Add Metrics

Gopkg.lock

@@ -701,7 +701,7 @@
   version = "v1.41.0"
 
 [[projects]]
-  digest = "1:9e53c5e9ee65a2c587d6ade11761ef2f976abfcd9599c5016b7046e63c1f7fb2"
+  digest = "1:bed40e7a58536b77890de9fc4911a1322a31cd2495bbcad8446d182063eb1ae4"
   name = "github.com/go-kit/kit"
   packages = [
     "log",
@@ -716,8 +716,8 @@
     "util/conn",
   ]
   pruneopts = "NUT"
-  revision = "ca4112baa34cb55091301bdc13b1420a122b1b9e"
-  version = "v0.7.0"
+  revision = "150a65a7ec6156b4b640c1fd55f26fd3d475d656"
+  version = "v0.9.0"
 
 [[projects]]
   digest = "1:341a7df38da99fe91ed40e4008c13cc5d02dcc98ed1a094360cb7d5df26d6d26"
@@ -735,14 +735,6 @@
   revision = "d4920dcf5b7689548a6db640278a9b35a5b48ec6"
   version = "v1.9.1"
 
-[[projects]]
-  digest = "1:8cf58169eb0a8c009ed3a4c36486980d602ab4cc4e478130493d6cd0404f889b"
-  name = "github.com/go-stack/stack"
-  packages = ["."]
-  pruneopts = "NUT"
-  revision = "54be5f394ed2c3e19dac9134a40a95ba5a017f7b"
-  version = "v1.5.4"
-
 [[projects]]
   digest = "1:6689652ec1f6e30455551da19c707f2bfac75e4df5c7bbe3f0ad7b49b9aa2cfc"
   name = "github.com/gogo/protobuf"
@@ -938,16 +930,16 @@
   version = "0.2.4"
 
 [[projects]]
-  digest = "1:9813d5a93abcc5690fa5830bf7186c835493516986be7a2b11b46e7b12e13317"
-  name = "github.com/influxdata/influxdb"
+  branch = "master"
+  digest = "1:50708c8fc92aec981df5c446581cf9f90ba9e2a5692118e0ce75d4534aaa14a2"
+  name = "github.com/influxdata/influxdb1-client"
   packages = [
-    "client/v2",
     "models",
     "pkg/escape",
+    "v2",
   ]
   pruneopts = "NUT"
-  revision = "2d474a3089bcfce6b472779be9470a1f0ef3d5e4"
-  version = "v1.3.7"
+  revision = "8ff2fc3824fcb533795f9a2f233275f0bb18d6c5"
 
 [[projects]]
   digest = "1:78efd72f12ed0244e5fbe82bd0ecdbaf3e21402ee9176525ef1138a2fc0d3b17"
@@ -1362,14 +1354,16 @@
   version = "v1.0.0"
 
 [[projects]]
-  digest = "1:d05ebef91c056e176dc4dfe905002bd3dd7b1dc8703b53bf6e88761053236a75"
+  digest = "1:097cc61836050f45cbb712ae3bb45d66fba464c16b8fac09907fa3c1f753eff6"
   name = "github.com/prometheus/client_golang"
   packages = [
     "prometheus",
+    "prometheus/internal",
     "prometheus/promhttp",
   ]
   pruneopts = "NUT"
-  revision = "08fd2e12372a66e68e30523c7642e0cbc3e4fbde"
+  revision = "4ab88e80c249ed361d3299e2930427d9ac43ef8d"
+  version = "v1.0.0"
 
 [[projects]]
   digest = "1:32d10bdfa8f09ecf13598324dba86ab891f11db3c538b6a34d1c3b5b99d7c36b"
@@ -1379,7 +1373,7 @@
   revision = "6f3806018612930941127f2a7c6c453ba2c527d2"
 
 [[projects]]
-  digest = "1:65f12bb82877d6e049a41b5feec5f79f11e3e0ea5748f677d68f206ac408c403"
+  digest = "1:d03ca24670416dc8fccc78b05d6736ec655416ca7db0a028e8fb92cfdfe3b55e"
   name = "github.com/prometheus/common"
   packages = [
     "expfmt",
@@ -1387,17 +1381,19 @@
     "model",
   ]
   pruneopts = "NUT"
-  revision = "49fee292b27bfff7f354ee0f64e1bc4850462edf"
+  revision = "31bed53e4047fd6c510e43a941f90cb31be0972a"
+  version = "v0.6.0"
 
 [[projects]]
-  digest = "1:60d19aad385900a8aa4a755524e68965fcb31b444ec30e673812e06c98674f2e"
+  digest = "1:19305fc369377c111c865a7a01e11c675c57c52a932353bbd4ea360bd5b72d99"
   name = "github.com/prometheus/procfs"
   packages = [
     ".",
-    "xfs",
+    "internal/fs",
   ]
   pruneopts = "NUT"
-  revision = "a1dba9ce8baed984a2495b658c82687f8157b98f"
+  revision = "3f98efb27840a48a7a2898ec80be07674d19f9c8"
+  version = "v0.0.3"
 
 [[projects]]
   branch = "containous-fork"
@@ -1857,7 +1853,7 @@
   version = "v1.20.1"
 
 [[projects]]
-  digest = "1:b49eceff862a3048ec28dad1fce40bcbdc1703119dbad35d7e5f1beb4f9a4527"
+  digest = "1:d732242a429138da899dfecea82b3c65b4157bdf0b5317c229d9c559b6c3450e"
   name = "gopkg.in/DataDog/dd-trace-go.v1"
   packages = [
     "ddtrace",
@@ -1866,10 +1862,12 @@
     "ddtrace/opentracer",
     "ddtrace/tracer",
     "internal/globalconfig",
+    "internal/log",
+    "internal/version",
   ]
   pruneopts = "NUT"
-  revision = "c19e9e56d5b5b71b6507ce1b0ec06d85aa3705a1"
-  version = "v1.14.0"
+  revision = "8d2998bc69008aa4553846ac9a044aa730bd4ce4"
+  version = "v1.15.0"
 
 [[projects]]
   digest = "1:c970218a20933dd0a2eb2006de922217fa9276f57d25009b2a934eb1c50031cc"
@@ -2263,7 +2261,7 @@
     "github.com/google/go-github/github",
     "github.com/gorilla/websocket",
     "github.com/hashicorp/go-version",
-    "github.com/influxdata/influxdb/client/v2",
+    "github.com/influxdata/influxdb1-client/v2",
     "github.com/instana/go-sensor",
     "github.com/libkermit/compose/check",
     "github.com/libkermit/docker",

Gopkg.toml

@@ -111,7 +111,11 @@ required = [
 
 [[constraint]]
   name = "github.com/go-kit/kit"
-  version = "0.7.0"
+  version = "v0.9.0"
+
+[[constraint]]
+  name = "github.com/prometheus/client_golang"
+  version = "v1.0.0"
 
 [[constraint]]
   branch = "master"
@@ -121,10 +125,6 @@ required = [
 #  name = "github.com/hashicorp/consul"
 #  version = "1.0.6"
 
-[[constraint]]
-  name = "github.com/influxdata/influxdb"
-  version = "1.3.7"
-
 #[[constraint]]
 #  branch = "master"
 #  name = "github.com/jjcollinge/servicefabric"
@@ -273,7 +273,7 @@ required = [
 
 [[constraint]]
   name = "gopkg.in/DataDog/dd-trace-go.v1"
-  version = "1.13.0"
+  version = "1.15.0"
 
 [[constraint]]
   name = "github.com/instana/go-sensor"

docs/content/observability/metrics/datadog.md

@@ -0,0 +1,106 @@
+# DataDog
+
+To enable the DataDog:
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.dataDog]
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.datadog
+```
+
+#### `address`
+
+_Required, Default="127.0.0.1:8125"_
+
+Address instructs exporter to send metrics to datadog-agent at this address.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.dataDog]
+    address = "127.0.0.1:8125"
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  dataDog:
+    address: 127.0.0.1:8125
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.datadog.address="127.0.0.1:8125"
+```
+
+#### `addEntryPointsLabels`
+
+_Optional, Default=true_
+
+Enable metrics on entry points.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.dataDog]
+    addEntryPointsLabels = true
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  dataDog:
+    addEntryPointsLabels: true
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.datadog.addEntryPointsLabels=true
+```
+
+#### `addServicesLabels`
+
+_Optional, Default=true_
+
+Enable metrics on services.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.dataDog]
+    addServicesLabels = true
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  dataDog:
+    addServicesLabels: true
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.datadog.addServicesLabels=true
+```
+
+#### `pushInterval`
+
+_Optional, Default=10s_
+
+The interval used by the exporter to push metrics to datadog-agent.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.dataDog]
+    pushInterval = 10s
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  dataDog:
+    pushInterval: 10s
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.datadog.pushInterval=10s
+```
+

docs/content/observability/metrics/influxdb.md

@@ -0,0 +1,225 @@
+# InfluxDB
+
+To enable the InfluxDB:
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb: {}
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb
+```
+
+#### `address`
+
+_Required, Default="localhost:8089"_
+
+Address instructs exporter to send metrics to influxdb at this address.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    address = "localhost:8089"
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    address: localhost:8089
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.address="localhost:8089"
+```
+
+#### `protocol`
+
+_Required, Default="udp"_
+
+InfluxDB's address protocol (udp or http).
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    protocol = "upd"
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    protocol: udp
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.protocol="udp"
+```
+
+#### `database`
+
+_Optional, Default=""_
+
+InfluxDB database used when protocol is http.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    database = ""
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    database: ""
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.database=""
+```
+
+#### `retentionPolicy`
+
+_Optional, Default=""_
+
+InfluxDB retention policy used when protocol is http.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    retentionPolicy = ""
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    retentionPolicy: ""
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.retentionPolicy=""
+```
+
+#### `username`
+
+_Optional, Default=""_
+
+InfluxDB username (only with http).
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    username = ""
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    username: ""
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.username=""
+```
+
+#### `password`
+
+_Optional, Default=""_
+
+InfluxDB password (only with http).
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    password = ""
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    password: ""
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.password=""
+```
+
+#### `addEntryPointsLabels`
+
+_Optional, Default=true_
+
+Enable metrics on entry points.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    addEntryPointsLabels = true
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    addEntryPointsLabels: true
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.addEntryPointsLabels=true
+```
+
+#### `addServicesLabels`
+
+_Optional, Default=true_
+
+Enable metrics on services.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    addServicesLabels = true
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    addServicesLabels: true
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.addServicesLabels=true
+```
+
+#### `pushInterval`
+
+_Optional, Default=10s_
+
+The interval used by the exporter to push metrics to influxdb.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.influxdb]
+    pushInterval = 10s
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  influxdb:
+    pushInterval: 10s
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.influxdb.pushInterval=10s
+```

docs/content/observability/metrics/overview.md

@@ -0,0 +1,26 @@
+# Metrics
+Metrics system
+{: .subtitle }
+
+Traefik supports 4 metrics backends:
+
+- [DataDog](./datadog.md)
+- [InfluxDB](./influxdb.md)
+- [Prometheus](./prometheus.md)
+- [StatsD](./statsd.md)
+
+## Configuration
+
+To enable metrics:
+
+```toml tab="File (TOML)"
+[metrics]
+```
+
+```yaml tab="File (TOML)"
+metrics: {}
+```
+
+```bash tab="CLI"
+--metrics
+```

docs/content/observability/metrics/prometheus.md

@@ -0,0 +1,139 @@
+# Prometheus
+
+To enable the Prometheus:
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.prometheus]
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  prometheus: {}
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.prometheus
+```
+
+#### `buckets`
+
+_Optional, Default="0.100000, 0.300000, 1.200000, 5.000000"_
+
+Buckets for latency metrics.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.prometheus]
+    buckets = [0.1,0.3,1.2,5.0]
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  prometheus:
+    buckets:
+    - 0.1
+    - 0.3
+    - 1.2
+    - 5.0
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.prometheus.buckets=0.100000, 0.300000, 1.200000, 5.000000
+```
+
+#### `entryPoint`
+
+_Optional, Default=traefik_
+
+Entry-point used by prometheus to expose metrics.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.prometheus]
+    entryPoint = traefik
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  prometheus:
+    entryPoint: traefik
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.prometheus.entryPoint=traefik
+```
+
+#### `middlewares`
+
+_Optional, Default=""_
+
+Middlewares.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.prometheus]
+    middlewares = ["xxx", "yyy"]
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  prometheus:
+    middlewares:
+    - xxx
+    - yyy
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.prometheus.middlewares="xxx,yyy"
+```
+
+#### `addEntryPointsLabels`
+
+_Optional, Default=true_
+
+Enable metrics on entry points.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.prometheus]
+    addEntryPointsLabels = true
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  prometheus:
+    addEntryPointsLabels: true
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.prometheus.addEntryPointsLabels=true
+```
+
+#### `addServicesLabels`
+
+_Optional, Default=true_
+
+Enable metrics on services.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.prometheus]
+    addServicesLabels = true
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  prometheus:
+    addServicesLabels: true
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.prometheus.addServicesLabels=true
+```

docs/content/observability/metrics/statsd.md

@@ -0,0 +1,110 @@
+# StatsD
+
+To enable the Statsd:
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.statsd]
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  statsd: {}
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.statsd
+```
+
+#### `address`
+
+_Required, Default="localhost:8125"_
+
+Address instructs exporter to send metrics to statsd at this address.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.statsd]
+    address = "localhost:8125"
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  statsd:
+    address: localhost:8125
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.statsd.address="localhost:8125"
+```
+
+#### `addEntryPointsLabels`
+
+_Optional, Default=true_
+
+Enable metrics on entry points.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.statsd]
+    addEntryPointsLabels = true
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  statsd:
+    addEntryPointsLabels: true
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.statsd.addEntryPointsLabels=true
+```
+
+#### `addServicesLabels`
+
+_Optional, Default=true_
+
+Enable metrics on services.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.statsd]
+    addServicesLabels = true
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  statsd:
+    addServicesLabels: true
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.statsd.addServicesLabels=true
+```
+
+#### `pushInterval`
+
+_Optional, Default=10s_
+
+The interval used by the exporter to push metrics to statsD.
+
+```toml tab="File (TOML)"
+[metrics]
+  [metrics.statsd]
+    pushInterval = 10s
+```
+
+```yaml tab="File (TOML)"
+metrics:
+  statsd:
+    pushInterval: 10s
+```
+
+```bash tab="CLI"
+--metrics
+--metrics.statsd.pushInterval=10s
+```

docs/content/reference/static-configuration/cli-ref.md

@@ -180,18 +180,30 @@ Log level set to traefik logs. (Default: ```ERROR```)
 `--metrics.datadog`:  
 DataDog metrics exporter type. (Default: ```false```)
 
+`--metrics.datadog.addentrypointslabels`:  
+Enable metrics on entry points. (Default: ```true```)
+
 `--metrics.datadog.address`:  
 DataDog's address. (Default: ```localhost:8125```)
 
+`--metrics.datadog.addserviceslabels`:  
+Enable metrics on services. (Default: ```true```)
+
 `--metrics.datadog.pushinterval`:  
 DataDog push interval. (Default: ```10```)
 
 `--metrics.influxdb`:  
 InfluxDB metrics exporter type. (Default: ```false```)
 
+`--metrics.influxdb.addentrypointslabels`:  
+Enable metrics on entry points. (Default: ```true```)
+
 `--metrics.influxdb.address`:  
 InfluxDB address. (Default: ```localhost:8089```)
 
+`--metrics.influxdb.addserviceslabels`:  
+Enable metrics on services. (Default: ```true```)
+
 `--metrics.influxdb.database`:  
 InfluxDB database used when protocol is http.
 
@@ -213,6 +225,12 @@ InfluxDB username (only with http).
 `--metrics.prometheus`:  
 Prometheus metrics exporter type. (Default: ```false```)
 
+`--metrics.prometheus.addentrypointslabels`:  
+Enable metrics on entry points. (Default: ```true```)
+
+`--metrics.prometheus.addserviceslabels`:  
+Enable metrics on services. (Default: ```true```)
+
 `--metrics.prometheus.buckets`:  
 Buckets for latency metrics. (Default: ```0.100000, 0.300000, 1.200000, 5.000000```)
 
@@ -225,9 +243,15 @@ Middlewares.
 `--metrics.statsd`:  
 StatsD metrics exporter type. (Default: ```false```)
 
+`--metrics.statsd.addentrypointslabels`:  
+Enable metrics on entry points. (Default: ```true```)
+
 `--metrics.statsd.address`:  
 StatsD address. (Default: ```localhost:8125```)
 
+`--metrics.statsd.addserviceslabels`:  
+Enable metrics on services. (Default: ```true```)
+
 `--metrics.statsd.pushinterval`:  
 StatsD push interval. (Default: ```10```)
 

docs/content/reference/static-configuration/env-ref.md

@@ -180,18 +180,30 @@ Log level set to traefik logs. (Default: ```ERROR```)
 `TRAEFIK_METRICS_DATADOG`:  
 DataDog metrics exporter type. (Default: ```false```)
 
+`TRAEFIK_METRICS_DATADOG_ADDENTRYPOINTSLABELS`:  
+Enable metrics on entry points. (Default: ```true```)
+
 `TRAEFIK_METRICS_DATADOG_ADDRESS`:  
 DataDog's address. (Default: ```localhost:8125```)
 
+`TRAEFIK_METRICS_DATADOG_ADDSERVICESLABELS`:  
+Enable metrics on services. (Default: ```true```)
+
 `TRAEFIK_METRICS_DATADOG_PUSHINTERVAL`:  
 DataDog push interval. (Default: ```10```)
 
 `TRAEFIK_METRICS_INFLUXDB`:  
 InfluxDB metrics exporter type. (Default: ```false```)
 
+`TRAEFIK_METRICS_INFLUXDB_ADDENTRYPOINTSLABELS`:  
+Enable metrics on entry points. (Default: ```true```)
+
 `TRAEFIK_METRICS_INFLUXDB_ADDRESS`:  
 InfluxDB address. (Default: ```localhost:8089```)
 
+`TRAEFIK_METRICS_INFLUXDB_ADDSERVICESLABELS`:  
+Enable metrics on services. (Default: ```true```)
+
 `TRAEFIK_METRICS_INFLUXDB_DATABASE`:  
 InfluxDB database used when protocol is http.
 
@@ -213,6 +225,12 @@ InfluxDB username (only with http).
 `TRAEFIK_METRICS_PROMETHEUS`:  
 Prometheus metrics exporter type. (Default: ```false```)
 
+`TRAEFIK_METRICS_PROMETHEUS_ADDENTRYPOINTSLABELS`:  
+Enable metrics on entry points. (Default: ```true```)
+
+`TRAEFIK_METRICS_PROMETHEUS_ADDSERVICESLABELS`:  
+Enable metrics on services. (Default: ```true```)
+
 `TRAEFIK_METRICS_PROMETHEUS_BUCKETS`:  
 Buckets for latency metrics. (Default: ```0.100000, 0.300000, 1.200000, 5.000000```)
 
@@ -225,9 +243,15 @@ Middlewares.
 `TRAEFIK_METRICS_STATSD`:  
 StatsD metrics exporter type. (Default: ```false```)
 
+`TRAEFIK_METRICS_STATSD_ADDENTRYPOINTSLABELS`:  
+Enable metrics on entry points. (Default: ```true```)
+
 `TRAEFIK_METRICS_STATSD_ADDRESS`:  
 StatsD address. (Default: ```localhost:8125```)
 
+`TRAEFIK_METRICS_STATSD_ADDSERVICESLABELS`:  
+Enable metrics on services. (Default: ```true```)
+
 `TRAEFIK_METRICS_STATSD_PUSHINTERVAL`:  
 StatsD push interval. (Default: ```10```)
 

docs/content/reference/static-configuration/file.toml

@@ -120,12 +120,18 @@
     buckets = [42.0, 42.0]
     entryPoint = "foobar"
     middlewares = ["foobar", "foobar"]
+    addEntryPointsLabels = true
+    addServicesLabels = true
   [metrics.dataDog]
     address = "foobar"
     pushInterval = "10s"
+    addEntryPointsLabels = true
+    addServicesLabels = true
   [metrics.statsD]
     address = "foobar"
     pushInterval = "10s"
+    addEntryPointsLabels = true
+    addServicesLabels = true
   [metrics.influxDB]
     address = "foobar"
     protocol = "foobar"
@@ -134,6 +140,8 @@
     retentionPolicy = "foobar"
     username = "foobar"
     password = "foobar"
+    addEntryPointsLabels = true
+    addServicesLabels = true
 
 [ping]
   entryPoint = "foobar"

docs/content/reference/static-configuration/file.yaml

@@ -131,12 +131,18 @@ metrics:
     middlewares:
     - foobar
     - foobar
+    addEntryPointsLabels: true
+    addServicesLabels: true
   dataDog:
     address: foobar
     pushInterval: 42
+    addEntryPointsLabels: true
+    addServicesLabels: true
   statsD:
     address: foobar
     pushInterval: 42
+    addEntryPointsLabels: true
+    addServicesLabels: true
   influxDB:
     address: foobar
     protocol: foobar
@@ -145,6 +151,8 @@ metrics:
     retentionPolicy: foobar
     username: foobar
     password: foobar
+    addEntryPointsLabels: true
+    addServicesLabels: true
 ping:
   entryPoint: foobar
   middlewares:

docs/mkdocs.yml

@@ -119,6 +119,12 @@ nav:
   - 'Observability':
       - 'Logs': 'observability/logs.md'
       - 'Access Logs': 'observability/access-logs.md'
+      - 'Metrics':
+          - 'Overview': 'observability/metrics/overview.md'
+          - 'DataDog': 'observability/metrics/datadog.md'
+          - 'InfluxDB': 'observability/metrics/influxdb.md'
+          - 'Prometheus': 'observability/metrics/prometheus.md'
+          - 'StatsD': 'observability/metrics/statsd.md'
       - 'Tracing':
           - 'Overview': 'observability/tracing/overview.md'
           - 'Jaeger': 'observability/tracing/jaeger.md'

pkg/metrics/datadog.go

@@ -20,18 +20,18 @@ var datadogTicker *time.Ticker
 
 // Metric names consistent with https://github.com/DataDog/integrations-extras/pull/64
 const (
-	ddMetricsBackendReqsName      = "backend.request.total"
-	ddMetricsBackendLatencyName   = "backend.request.duration"
-	ddRetriesTotalName            = "backend.retries.total"
+	ddMetricsServiceReqsName      = "service.request.total"
+	ddMetricsServiceLatencyName   = "service.request.duration"
+	ddRetriesTotalName            = "service.retries.total"
 	ddConfigReloadsName           = "config.reload.total"
 	ddConfigReloadsFailureTagName = "failure"
 	ddLastConfigReloadSuccessName = "config.reload.lastSuccessTimestamp"
 	ddLastConfigReloadFailureName = "config.reload.lastFailureTimestamp"
-	ddEntrypointReqsName          = "entrypoint.request.total"
-	ddEntrypointReqDurationName   = "entrypoint.request.duration"
-	ddEntrypointOpenConnsName     = "entrypoint.connections.open"
-	ddOpenConnsName               = "backend.connections.open"
-	ddServerUpName                = "backend.server.up"
+	ddEntryPointReqsName          = "entrypoint.request.total"
+	ddEntryPointReqDurationName   = "entrypoint.request.duration"
+	ddEntryPointOpenConnsName     = "entrypoint.connections.open"
+	ddOpenConnsName               = "service.connections.open"
+	ddServerUpName                = "service.server.up"
 )
 
 // RegisterDatadog registers the metrics pusher if this didn't happen yet and creates a datadog Registry instance.
@@ -41,19 +41,26 @@ func RegisterDatadog(ctx context.Context, config *types.DataDog) Registry {
 	}
 
 	registry := &standardRegistry{
-		enabled:                        true,
-		configReloadsCounter:           datadogClient.NewCounter(ddConfigReloadsName, 1.0),
-		configReloadsFailureCounter:    datadogClient.NewCounter(ddConfigReloadsName, 1.0).With(ddConfigReloadsFailureTagName, "true"),
-		lastConfigReloadSuccessGauge:   datadogClient.NewGauge(ddLastConfigReloadSuccessName),
-		lastConfigReloadFailureGauge:   datadogClient.NewGauge(ddLastConfigReloadFailureName),
-		entrypointReqsCounter:          datadogClient.NewCounter(ddEntrypointReqsName, 1.0),
-		entrypointReqDurationHistogram: datadogClient.NewHistogram(ddEntrypointReqDurationName, 1.0),
-		entrypointOpenConnsGauge:       datadogClient.NewGauge(ddEntrypointOpenConnsName),
-		backendReqsCounter:             datadogClient.NewCounter(ddMetricsBackendReqsName, 1.0),
-		backendReqDurationHistogram:    datadogClient.NewHistogram(ddMetricsBackendLatencyName, 1.0),
-		backendRetriesCounter:          datadogClient.NewCounter(ddRetriesTotalName, 1.0),
-		backendOpenConnsGauge:          datadogClient.NewGauge(ddOpenConnsName),
-		backendServerUpGauge:           datadogClient.NewGauge(ddServerUpName),
+		configReloadsCounter:         datadogClient.NewCounter(ddConfigReloadsName, 1.0),
+		configReloadsFailureCounter:  datadogClient.NewCounter(ddConfigReloadsName, 1.0).With(ddConfigReloadsFailureTagName, "true"),
+		lastConfigReloadSuccessGauge: datadogClient.NewGauge(ddLastConfigReloadSuccessName),
+		lastConfigReloadFailureGauge: datadogClient.NewGauge(ddLastConfigReloadFailureName),
+	}
+
+	if config.AddEntryPointsLabels {
+		registry.epEnabled = config.AddEntryPointsLabels
+		registry.entryPointReqsCounter = datadogClient.NewCounter(ddEntryPointReqsName, 1.0)
+		registry.entryPointReqDurationHistogram = datadogClient.NewHistogram(ddEntryPointReqDurationName, 1.0)
+		registry.entryPointOpenConnsGauge = datadogClient.NewGauge(ddEntryPointOpenConnsName)
+	}
+
+	if config.AddServicesLabels {
+		registry.svcEnabled = config.AddServicesLabels
+		registry.serviceReqsCounter = datadogClient.NewCounter(ddMetricsServiceReqsName, 1.0)
+		registry.serviceReqDurationHistogram = datadogClient.NewHistogram(ddMetricsServiceLatencyName, 1.0)
+		registry.serviceRetriesCounter = datadogClient.NewCounter(ddRetriesTotalName, 1.0)
+		registry.serviceOpenConnsGauge = datadogClient.NewGauge(ddOpenConnsName)
+		registry.serviceServerUpGauge = datadogClient.NewGauge(ddServerUpName)
 	}
 
 	return registry
@@ -68,7 +75,7 @@ func initDatadogClient(ctx context.Context, config *types.DataDog) *time.Ticker
 	report := time.NewTicker(time.Duration(config.PushInterval))
 
 	safe.Go(func() {
-		datadogClient.SendLoop(report.C, "udp", address)
+		datadogClient.SendLoop(ctx, report.C, "udp", address)
 	})
 
 	return report

pkg/metrics/datadog_test.go

@@ -16,38 +16,38 @@ func TestDatadog(t *testing.T) {
 	// This is needed to make sure that UDP Listener listens for data a bit longer, otherwise it will quit after a millisecond
 	udp.Timeout = 5 * time.Second
 
-	datadogRegistry := RegisterDatadog(context.Background(), &types.DataDog{Address: ":18125", PushInterval: types.Duration(time.Second)})
+	datadogRegistry := RegisterDatadog(context.Background(), &types.DataDog{Address: ":18125", PushInterval: types.Duration(time.Second), AddEntryPointsLabels: true, AddServicesLabels: true})
 	defer StopDatadog()
 
-	if !datadogRegistry.IsEnabled() {
+	if !datadogRegistry.IsEpEnabled() || !datadogRegistry.IsSvcEnabled() {
 		t.Errorf("DatadogRegistry should return true for IsEnabled()")
 	}
 
 	expected := []string{
 		// We are only validating counts, as it is nearly impossible to validate latency, since it varies every run
-		"traefik.backend.request.total:1.000000|c|#service:test,code:404,method:GET\n",
-		"traefik.backend.request.total:1.000000|c|#service:test,code:200,method:GET\n",
-		"traefik.backend.retries.total:2.000000|c|#service:test\n",
-		"traefik.backend.request.duration:10000.000000|h|#service:test,code:200\n",
+		"traefik.service.request.total:1.000000|c|#service:test,code:404,method:GET\n",
+		"traefik.service.request.total:1.000000|c|#service:test,code:200,method:GET\n",
+		"traefik.service.retries.total:2.000000|c|#service:test\n",
+		"traefik.service.request.duration:10000.000000|h|#service:test,code:200\n",
 		"traefik.config.reload.total:1.000000|c\n",
 		"traefik.config.reload.total:1.000000|c|#failure:true\n",
 		"traefik.entrypoint.request.total:1.000000|c|#entrypoint:test\n",
 		"traefik.entrypoint.request.duration:10000.000000|h|#entrypoint:test\n",
 		"traefik.entrypoint.connections.open:1.000000|g|#entrypoint:test\n",
-		"traefik.backend.server.up:1.000000|g|#backend:test,url:http://127.0.0.1,one:two\n",
+		"traefik.service.server.up:1.000000|g|#service:test,url:http://127.0.0.1,one:two\n",
 	}
 
 	udp.ShouldReceiveAll(t, expected, func() {
-		datadogRegistry.BackendReqsCounter().With("service", "test", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet).Add(1)
-		datadogRegistry.BackendReqsCounter().With("service", "test", "code", strconv.Itoa(http.StatusNotFound), "method", http.MethodGet).Add(1)
-		datadogRegistry.BackendReqDurationHistogram().With("service", "test", "code", strconv.Itoa(http.StatusOK)).Observe(10000)
-		datadogRegistry.BackendRetriesCounter().With("service", "test").Add(1)
-		datadogRegistry.BackendRetriesCounter().With("service", "test").Add(1)
+		datadogRegistry.ServiceReqsCounter().With("service", "test", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet).Add(1)
+		datadogRegistry.ServiceReqsCounter().With("service", "test", "code", strconv.Itoa(http.StatusNotFound), "method", http.MethodGet).Add(1)
+		datadogRegistry.ServiceReqDurationHistogram().With("service", "test", "code", strconv.Itoa(http.StatusOK)).Observe(10000)
+		datadogRegistry.ServiceRetriesCounter().With("service", "test").Add(1)
+		datadogRegistry.ServiceRetriesCounter().With("service", "test").Add(1)
 		datadogRegistry.ConfigReloadsCounter().Add(1)
 		datadogRegistry.ConfigReloadsFailureCounter().Add(1)
-		datadogRegistry.EntrypointReqsCounter().With("entrypoint", "test").Add(1)
-		datadogRegistry.EntrypointReqDurationHistogram().With("entrypoint", "test").Observe(10000)
-		datadogRegistry.EntrypointOpenConnsGauge().With("entrypoint", "test").Set(1)
-		datadogRegistry.BackendServerUpGauge().With("backend", "test", "url", "http://127.0.0.1", "one", "two").Set(1)
+		datadogRegistry.EntryPointReqsCounter().With("entrypoint", "test").Add(1)
+		datadogRegistry.EntryPointReqDurationHistogram().With("entrypoint", "test").Observe(10000)
+		datadogRegistry.EntryPointOpenConnsGauge().With("entrypoint", "test").Set(1)
+		datadogRegistry.ServiceServerUpGauge().With("service", "test", "url", "http://127.0.0.1", "one", "two").Set(1)
 	})
 }

pkg/metrics/influxdb.go

@@ -13,7 +13,7 @@ import (
 	"github.com/containous/traefik/pkg/types"
 	kitlog "github.com/go-kit/kit/log"
 	"github.com/go-kit/kit/metrics/influx"
-	influxdb "github.com/influxdata/influxdb/client/v2"
+	influxdb "github.com/influxdata/influxdb1-client/v2"
 )
 
 var influxDBClient *influx.Influx
@@ -26,18 +26,18 @@ type influxDBWriter struct {
 var influxDBTicker *time.Ticker
 
 const (
-	influxDBMetricsBackendReqsName      = "traefik.backend.requests.total"
-	influxDBMetricsBackendLatencyName   = "traefik.backend.request.duration"
-	influxDBRetriesTotalName            = "traefik.backend.retries.total"
+	influxDBMetricsServiceReqsName      = "traefik.service.requests.total"
+	influxDBMetricsServiceLatencyName   = "traefik.service.request.duration"
+	influxDBRetriesTotalName            = "traefik.service.retries.total"
 	influxDBConfigReloadsName           = "traefik.config.reload.total"
 	influxDBConfigReloadsFailureName    = influxDBConfigReloadsName + ".failure"
 	influxDBLastConfigReloadSuccessName = "traefik.config.reload.lastSuccessTimestamp"
 	influxDBLastConfigReloadFailureName = "traefik.config.reload.lastFailureTimestamp"
-	influxDBEntrypointReqsName          = "traefik.entrypoint.requests.total"
-	influxDBEntrypointReqDurationName   = "traefik.entrypoint.request.duration"
-	influxDBEntrypointOpenConnsName     = "traefik.entrypoint.connections.open"
-	influxDBOpenConnsName               = "traefik.backend.connections.open"
-	influxDBServerUpName                = "traefik.backend.server.up"
+	influxDBEntryPointReqsName          = "traefik.entrypoint.requests.total"
+	influxDBEntryPointReqDurationName   = "traefik.entrypoint.request.duration"
+	influxDBEntryPointOpenConnsName     = "traefik.entrypoint.connections.open"
+	influxDBOpenConnsName               = "traefik.service.connections.open"
+	influxDBServerUpName                = "traefik.service.server.up"
 )
 
 const (
@@ -51,24 +51,33 @@ func RegisterInfluxDB(ctx context.Context, config *types.InfluxDB) Registry {
 		influxDBClient = initInfluxDBClient(ctx, config)
 	}
 	if influxDBTicker == nil {
-		influxDBTicker = initInfluxDBTicker(config)
+		influxDBTicker = initInfluxDBTicker(ctx, config)
 	}
 
-	return &standardRegistry{
-		enabled:                        true,
-		configReloadsCounter:           influxDBClient.NewCounter(influxDBConfigReloadsName),
-		configReloadsFailureCounter:    influxDBClient.NewCounter(influxDBConfigReloadsFailureName),
-		lastConfigReloadSuccessGauge:   influxDBClient.NewGauge(influxDBLastConfigReloadSuccessName),
-		lastConfigReloadFailureGauge:   influxDBClient.NewGauge(influxDBLastConfigReloadFailureName),
-		entrypointReqsCounter:          influxDBClient.NewCounter(influxDBEntrypointReqsName),
-		entrypointReqDurationHistogram: influxDBClient.NewHistogram(influxDBEntrypointReqDurationName),
-		entrypointOpenConnsGauge:       influxDBClient.NewGauge(influxDBEntrypointOpenConnsName),
-		backendReqsCounter:             influxDBClient.NewCounter(influxDBMetricsBackendReqsName),
-		backendReqDurationHistogram:    influxDBClient.NewHistogram(influxDBMetricsBackendLatencyName),
-		backendRetriesCounter:          influxDBClient.NewCounter(influxDBRetriesTotalName),
-		backendOpenConnsGauge:          influxDBClient.NewGauge(influxDBOpenConnsName),
-		backendServerUpGauge:           influxDBClient.NewGauge(influxDBServerUpName),
+	registry := &standardRegistry{
+		configReloadsCounter:         influxDBClient.NewCounter(influxDBConfigReloadsName),
+		configReloadsFailureCounter:  influxDBClient.NewCounter(influxDBConfigReloadsFailureName),
+		lastConfigReloadSuccessGauge: influxDBClient.NewGauge(influxDBLastConfigReloadSuccessName),
+		lastConfigReloadFailureGauge: influxDBClient.NewGauge(influxDBLastConfigReloadFailureName),
 	}
+
+	if config.AddEntryPointsLabels {
+		registry.epEnabled = config.AddEntryPointsLabels
+		registry.entryPointReqsCounter = influxDBClient.NewCounter(influxDBEntryPointReqsName)
+		registry.entryPointReqDurationHistogram = influxDBClient.NewHistogram(influxDBEntryPointReqDurationName)
+		registry.entryPointOpenConnsGauge = influxDBClient.NewGauge(influxDBEntryPointOpenConnsName)
+	}
+
+	if config.AddServicesLabels {
+		registry.svcEnabled = config.AddServicesLabels
+		registry.serviceReqsCounter = influxDBClient.NewCounter(influxDBMetricsServiceReqsName)
+		registry.serviceReqDurationHistogram = influxDBClient.NewHistogram(influxDBMetricsServiceLatencyName)
+		registry.serviceRetriesCounter = influxDBClient.NewCounter(influxDBRetriesTotalName)
+		registry.serviceOpenConnsGauge = influxDBClient.NewGauge(influxDBOpenConnsName)
+		registry.serviceServerUpGauge = influxDBClient.NewGauge(influxDBServerUpName)
+	}
+
+	return registry
 }
 
 // initInfluxDBTicker creates a influxDBClient
@@ -115,12 +124,12 @@ func initInfluxDBClient(ctx context.Context, config *types.InfluxDB) *influx.Inf
 }
 
 // initInfluxDBTicker initializes metrics pusher
-func initInfluxDBTicker(config *types.InfluxDB) *time.Ticker {
+func initInfluxDBTicker(ctx context.Context, config *types.InfluxDB) *time.Ticker {
 	report := time.NewTicker(time.Duration(config.PushInterval))
 
 	safe.Go(func() {
 		var buf bytes.Buffer
-		influxDBClient.WriteLoop(report.C, &influxDBWriter{buf: buf, config: config})
+		influxDBClient.WriteLoop(ctx, report.C, &influxDBWriter{buf: buf, config: config})
 	})
 
 	return report

pkg/metrics/influxdb_test.go

@@ -20,35 +20,35 @@ func TestInfluxDB(t *testing.T) {
 	// This is needed to make sure that UDP Listener listens for data a bit longer, otherwise it will quit after a millisecond
 	udp.Timeout = 5 * time.Second
 
-	influxDBRegistry := RegisterInfluxDB(context.Background(), &types.InfluxDB{Address: ":8089", PushInterval: types.Duration(time.Second)})
+	influxDBRegistry := RegisterInfluxDB(context.Background(), &types.InfluxDB{Address: ":8089", PushInterval: types.Duration(time.Second), AddEntryPointsLabels: true, AddServicesLabels: true})
 	defer StopInfluxDB()
 
-	if !influxDBRegistry.IsEnabled() {
-		t.Fatalf("InfluxDB registry must be enabled")
+	if !influxDBRegistry.IsEpEnabled() || !influxDBRegistry.IsSvcEnabled() {
+		t.Fatalf("InfluxDB registry must be epEnabled")
 	}
 
-	expectedBackend := []string{
-		`(traefik\.backend\.requests\.total,backend=test,code=200,method=GET count=1) [\d]{19}`,
-		`(traefik\.backend\.requests\.total,backend=test,code=404,method=GET count=1) [\d]{19}`,
-		`(traefik\.backend\.request\.duration,backend=test,code=200 p50=10000,p90=10000,p95=10000,p99=10000) [\d]{19}`,
-		`(traefik\.backend\.retries\.total(?:,code=[\d]{3},method=GET)?,backend=test count=2) [\d]{19}`,
+	expectedService := []string{
+		`(traefik\.service\.requests\.total,code=200,method=GET,service=test count=1) [\d]{19}`,
+		`(traefik\.service\.requests\.total,code=404,method=GET,service=test count=1) [\d]{19}`,
+		`(traefik\.service\.request\.duration,code=200,service=test p50=10000,p90=10000,p95=10000,p99=10000) [\d]{19}`,
+		`(traefik\.service\.retries\.total(?:,code=[\d]{3},method=GET)?,service=test count=2) [\d]{19}`,
 		`(traefik\.config\.reload\.total(?:[a-z=0-9A-Z,]+)? count=1) [\d]{19}`,
 		`(traefik\.config\.reload\.total\.failure(?:[a-z=0-9A-Z,]+)? count=1) [\d]{19}`,
-		`(traefik\.backend\.server\.up,backend=test(?:[a-z=0-9A-Z,]+)?,url=http://127.0.0.1 value=1) [\d]{19}`,
+		`(traefik\.service\.server\.up,service=test(?:[a-z=0-9A-Z,]+)?,url=http://127.0.0.1 value=1) [\d]{19}`,
 	}
 
-	msgBackend := udp.ReceiveString(t, func() {
-		influxDBRegistry.BackendReqsCounter().With("backend", "test", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet).Add(1)
-		influxDBRegistry.BackendReqsCounter().With("backend", "test", "code", strconv.Itoa(http.StatusNotFound), "method", http.MethodGet).Add(1)
-		influxDBRegistry.BackendRetriesCounter().With("backend", "test").Add(1)
-		influxDBRegistry.BackendRetriesCounter().With("backend", "test").Add(1)
-		influxDBRegistry.BackendReqDurationHistogram().With("backend", "test", "code", strconv.Itoa(http.StatusOK)).Observe(10000)
+	msgService := udp.ReceiveString(t, func() {
+		influxDBRegistry.ServiceReqsCounter().With("service", "test", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet).Add(1)
+		influxDBRegistry.ServiceReqsCounter().With("service", "test", "code", strconv.Itoa(http.StatusNotFound), "method", http.MethodGet).Add(1)
+		influxDBRegistry.ServiceRetriesCounter().With("service", "test").Add(1)
+		influxDBRegistry.ServiceRetriesCounter().With("service", "test").Add(1)
+		influxDBRegistry.ServiceReqDurationHistogram().With("service", "test", "code", strconv.Itoa(http.StatusOK)).Observe(10000)
 		influxDBRegistry.ConfigReloadsCounter().Add(1)
 		influxDBRegistry.ConfigReloadsFailureCounter().Add(1)
-		influxDBRegistry.BackendServerUpGauge().With("backend", "test", "url", "http://127.0.0.1").Set(1)
+		influxDBRegistry.ServiceServerUpGauge().With("service", "test", "url", "http://127.0.0.1").Set(1)
 	})
 
-	assertMessage(t, msgBackend, expectedBackend)
+	assertMessage(t, msgService, expectedService)
 
 	expectedEntrypoint := []string{
 		`(traefik\.entrypoint\.requests\.total,entrypoint=test(?:[a-z=0-9A-Z,:/.]+)? count=1) [\d]{19}`,
@@ -57,9 +57,9 @@ func TestInfluxDB(t *testing.T) {
 	}
 
 	msgEntrypoint := udp.ReceiveString(t, func() {
-		influxDBRegistry.EntrypointReqsCounter().With("entrypoint", "test").Add(1)
-		influxDBRegistry.EntrypointReqDurationHistogram().With("entrypoint", "test").Observe(10000)
-		influxDBRegistry.EntrypointOpenConnsGauge().With("entrypoint", "test").Set(1)
+		influxDBRegistry.EntryPointReqsCounter().With("entrypoint", "test").Add(1)
+		influxDBRegistry.EntryPointReqDurationHistogram().With("entrypoint", "test").Observe(10000)
+		influxDBRegistry.EntryPointOpenConnsGauge().With("entrypoint", "test").Set(1)
 
 	})
 
@@ -76,38 +76,38 @@ func TestInfluxDBHTTP(t *testing.T) {
 		}
 		bodyStr := string(body)
 		c <- &bodyStr
-		fmt.Fprintln(w, "ok")
+		_, _ = fmt.Fprintln(w, "ok")
 	}))
 	defer ts.Close()
 
-	influxDBRegistry := RegisterInfluxDB(context.Background(), &types.InfluxDB{Address: ts.URL, Protocol: "http", PushInterval: types.Duration(time.Second), Database: "test", RetentionPolicy: "autogen"})
+	influxDBRegistry := RegisterInfluxDB(context.Background(), &types.InfluxDB{Address: ts.URL, Protocol: "http", PushInterval: types.Duration(time.Second), Database: "test", RetentionPolicy: "autogen", AddEntryPointsLabels: true, AddServicesLabels: true})
 	defer StopInfluxDB()
 
-	if !influxDBRegistry.IsEnabled() {
-		t.Fatalf("InfluxDB registry must be enabled")
+	if !influxDBRegistry.IsEpEnabled() || !influxDBRegistry.IsSvcEnabled() {
+		t.Fatalf("InfluxDB registry must be epEnabled")
 	}
 
-	expectedBackend := []string{
-		`(traefik\.backend\.requests\.total,backend=test,code=200,method=GET count=1) [\d]{19}`,
-		`(traefik\.backend\.requests\.total,backend=test,code=404,method=GET count=1) [\d]{19}`,
-		`(traefik\.backend\.request\.duration,backend=test,code=200 p50=10000,p90=10000,p95=10000,p99=10000) [\d]{19}`,
-		`(traefik\.backend\.retries\.total(?:,code=[\d]{3},method=GET)?,backend=test count=2) [\d]{19}`,
+	expectedService := []string{
+		`(traefik\.service\.requests\.total,code=200,method=GET,service=test count=1) [\d]{19}`,
+		`(traefik\.service\.requests\.total,code=404,method=GET,service=test count=1) [\d]{19}`,
+		`(traefik\.service\.request\.duration,code=200,service=test p50=10000,p90=10000,p95=10000,p99=10000) [\d]{19}`,
+		`(traefik\.service\.retries\.total(?:,code=[\d]{3},method=GET)?,service=test count=2) [\d]{19}`,
 		`(traefik\.config\.reload\.total(?:[a-z=0-9A-Z,]+)? count=1) [\d]{19}`,
 		`(traefik\.config\.reload\.total\.failure(?:[a-z=0-9A-Z,]+)? count=1) [\d]{19}`,
-		`(traefik\.backend\.server\.up,backend=test(?:[a-z=0-9A-Z,]+)?,url=http://127.0.0.1 value=1) [\d]{19}`,
+		`(traefik\.service\.server\.up,service=test(?:[a-z=0-9A-Z,]+)?,url=http://127.0.0.1 value=1) [\d]{19}`,
 	}
 
-	influxDBRegistry.BackendReqsCounter().With("backend", "test", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet).Add(1)
-	influxDBRegistry.BackendReqsCounter().With("backend", "test", "code", strconv.Itoa(http.StatusNotFound), "method", http.MethodGet).Add(1)
-	influxDBRegistry.BackendRetriesCounter().With("backend", "test").Add(1)
-	influxDBRegistry.BackendRetriesCounter().With("backend", "test").Add(1)
-	influxDBRegistry.BackendReqDurationHistogram().With("backend", "test", "code", strconv.Itoa(http.StatusOK)).Observe(10000)
+	influxDBRegistry.ServiceReqsCounter().With("service", "test", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet).Add(1)
+	influxDBRegistry.ServiceReqsCounter().With("service", "test", "code", strconv.Itoa(http.StatusNotFound), "method", http.MethodGet).Add(1)
+	influxDBRegistry.ServiceRetriesCounter().With("service", "test").Add(1)
+	influxDBRegistry.ServiceRetriesCounter().With("service", "test").Add(1)
+	influxDBRegistry.ServiceReqDurationHistogram().With("service", "test", "code", strconv.Itoa(http.StatusOK)).Observe(10000)
 	influxDBRegistry.ConfigReloadsCounter().Add(1)
 	influxDBRegistry.ConfigReloadsFailureCounter().Add(1)
-	influxDBRegistry.BackendServerUpGauge().With("backend", "test", "url", "http://127.0.0.1").Set(1)
-	msgBackend := <-c
+	influxDBRegistry.ServiceServerUpGauge().With("service", "test", "url", "http://127.0.0.1").Set(1)
+	msgService := <-c
 
-	assertMessage(t, *msgBackend, expectedBackend)
+	assertMessage(t, *msgService, expectedService)
 
 	expectedEntrypoint := []string{
 		`(traefik\.entrypoint\.requests\.total,entrypoint=test(?:[a-z=0-9A-Z,:/.]+)? count=1) [\d]{19}`,
@@ -115,9 +115,9 @@ func TestInfluxDBHTTP(t *testing.T) {
 		`(traefik\.entrypoint\.connections\.open,entrypoint=test value=1) [\d]{19}`,
 	}
 
-	influxDBRegistry.EntrypointReqsCounter().With("entrypoint", "test").Add(1)
-	influxDBRegistry.EntrypointReqDurationHistogram().With("entrypoint", "test").Observe(10000)
-	influxDBRegistry.EntrypointOpenConnsGauge().With("entrypoint", "test").Set(1)
+	influxDBRegistry.EntryPointReqsCounter().With("entrypoint", "test").Add(1)
+	influxDBRegistry.EntryPointReqDurationHistogram().With("entrypoint", "test").Observe(10000)
+	influxDBRegistry.EntryPointOpenConnsGauge().With("entrypoint", "test").Set(1)
 	msgEntrypoint := <-c
 
 	assertMessage(t, *msgEntrypoint, expectedEntrypoint)

pkg/metrics/metrics.go

@@ -7,8 +7,10 @@ import (
 
 // Registry has to implemented by any system that wants to monitor and expose metrics.
 type Registry interface {
-	// IsEnabled shows whether metrics instrumentation is enabled.
-	IsEnabled() bool
+	// IsEpEnabled shows whether metrics instrumentation is enabled on entry points.
+	IsEpEnabled() bool
+	// IsSvcEnabled shows whether metrics instrumentation is enabled on services.
+	IsSvcEnabled() bool
 
 	// server metrics
 	ConfigReloadsCounter() metrics.Counter
@@ -17,16 +19,16 @@ type Registry interface {
 	LastConfigReloadFailureGauge() metrics.Gauge
 
 	// entry point metrics
-	EntrypointReqsCounter() metrics.Counter
-	EntrypointReqDurationHistogram() metrics.Histogram
-	EntrypointOpenConnsGauge() metrics.Gauge
+	EntryPointReqsCounter() metrics.Counter
+	EntryPointReqDurationHistogram() metrics.Histogram
+	EntryPointOpenConnsGauge() metrics.Gauge
 
-	// backend metrics
-	BackendReqsCounter() metrics.Counter
-	BackendReqDurationHistogram() metrics.Histogram
-	BackendOpenConnsGauge() metrics.Gauge
-	BackendRetriesCounter() metrics.Counter
-	BackendServerUpGauge() metrics.Gauge
+	// service metrics
+	ServiceReqsCounter() metrics.Counter
+	ServiceReqDurationHistogram() metrics.Histogram
+	ServiceOpenConnsGauge() metrics.Gauge
+	ServiceRetriesCounter() metrics.Counter
+	ServiceServerUpGauge() metrics.Gauge
 }
 
 // NewVoidRegistry is a noop implementation of metrics.Registry.
@@ -43,14 +45,14 @@ func NewMultiRegistry(registries []Registry) Registry {
 	var configReloadsFailureCounter []metrics.Counter
 	var lastConfigReloadSuccessGauge []metrics.Gauge
 	var lastConfigReloadFailureGauge []metrics.Gauge
-	var entrypointReqsCounter []metrics.Counter
-	var entrypointReqDurationHistogram []metrics.Histogram
-	var entrypointOpenConnsGauge []metrics.Gauge
-	var backendReqsCounter []metrics.Counter
-	var backendReqDurationHistogram []metrics.Histogram
-	var backendOpenConnsGauge []metrics.Gauge
-	var backendRetriesCounter []metrics.Counter
-	var backendServerUpGauge []metrics.Gauge
+	var entryPointReqsCounter []metrics.Counter
+	var entryPointReqDurationHistogram []metrics.Histogram
+	var entryPointOpenConnsGauge []metrics.Gauge
+	var serviceReqsCounter []metrics.Counter
+	var serviceReqDurationHistogram []metrics.Histogram
+	var serviceOpenConnsGauge []metrics.Gauge
+	var serviceRetriesCounter []metrics.Counter
+	var serviceServerUpGauge []metrics.Gauge
 
 	for _, r := range registries {
 		if r.ConfigReloadsCounter() != nil {
@@ -65,67 +67,73 @@ func NewMultiRegistry(registries []Registry) Registry {
 		if r.LastConfigReloadFailureGauge() != nil {
 			lastConfigReloadFailureGauge = append(lastConfigReloadFailureGauge, r.LastConfigReloadFailureGauge())
 		}
-		if r.EntrypointReqsCounter() != nil {
-			entrypointReqsCounter = append(entrypointReqsCounter, r.EntrypointReqsCounter())
+		if r.EntryPointReqsCounter() != nil {
+			entryPointReqsCounter = append(entryPointReqsCounter, r.EntryPointReqsCounter())
 		}
-		if r.EntrypointReqDurationHistogram() != nil {
-			entrypointReqDurationHistogram = append(entrypointReqDurationHistogram, r.EntrypointReqDurationHistogram())
+		if r.EntryPointReqDurationHistogram() != nil {
+			entryPointReqDurationHistogram = append(entryPointReqDurationHistogram, r.EntryPointReqDurationHistogram())
 		}
-		if r.EntrypointOpenConnsGauge() != nil {
-			entrypointOpenConnsGauge = append(entrypointOpenConnsGauge, r.EntrypointOpenConnsGauge())
+		if r.EntryPointOpenConnsGauge() != nil {
+			entryPointOpenConnsGauge = append(entryPointOpenConnsGauge, r.EntryPointOpenConnsGauge())
 		}
-		if r.BackendReqsCounter() != nil {
-			backendReqsCounter = append(backendReqsCounter, r.BackendReqsCounter())
+		if r.ServiceReqsCounter() != nil {
+			serviceReqsCounter = append(serviceReqsCounter, r.ServiceReqsCounter())
 		}
-		if r.BackendReqDurationHistogram() != nil {
-			backendReqDurationHistogram = append(backendReqDurationHistogram, r.BackendReqDurationHistogram())
+		if r.ServiceReqDurationHistogram() != nil {
+			serviceReqDurationHistogram = append(serviceReqDurationHistogram, r.ServiceReqDurationHistogram())
 		}
-		if r.BackendOpenConnsGauge() != nil {
-			backendOpenConnsGauge = append(backendOpenConnsGauge, r.BackendOpenConnsGauge())
+		if r.ServiceOpenConnsGauge() != nil {
+			serviceOpenConnsGauge = append(serviceOpenConnsGauge, r.ServiceOpenConnsGauge())
 		}
-		if r.BackendRetriesCounter() != nil {
-			backendRetriesCounter = append(backendRetriesCounter, r.BackendRetriesCounter())
+		if r.ServiceRetriesCounter() != nil {
+			serviceRetriesCounter = append(serviceRetriesCounter, r.ServiceRetriesCounter())
 		}
-		if r.BackendServerUpGauge() != nil {
-			backendServerUpGauge = append(backendServerUpGauge, r.BackendServerUpGauge())
+		if r.ServiceServerUpGauge() != nil {
+			serviceServerUpGauge = append(serviceServerUpGauge, r.ServiceServerUpGauge())
 		}
 	}
 
 	return &standardRegistry{
-		enabled:                        len(registries) > 0,
+		epEnabled:                      len(entryPointReqsCounter) > 0 || len(entryPointReqDurationHistogram) > 0 || len(entryPointOpenConnsGauge) > 0,
+		svcEnabled:                     len(serviceReqsCounter) > 0 || len(serviceReqDurationHistogram) > 0 || len(serviceOpenConnsGauge) > 0 || len(serviceRetriesCounter) > 0 || len(serviceServerUpGauge) > 0,
 		configReloadsCounter:           multi.NewCounter(configReloadsCounter...),
 		configReloadsFailureCounter:    multi.NewCounter(configReloadsFailureCounter...),
 		lastConfigReloadSuccessGauge:   multi.NewGauge(lastConfigReloadSuccessGauge...),
 		lastConfigReloadFailureGauge:   multi.NewGauge(lastConfigReloadFailureGauge...),
-		entrypointReqsCounter:          multi.NewCounter(entrypointReqsCounter...),
-		entrypointReqDurationHistogram: multi.NewHistogram(entrypointReqDurationHistogram...),
-		entrypointOpenConnsGauge:       multi.NewGauge(entrypointOpenConnsGauge...),
-		backendReqsCounter:             multi.NewCounter(backendReqsCounter...),
-		backendReqDurationHistogram:    multi.NewHistogram(backendReqDurationHistogram...),
-		backendOpenConnsGauge:          multi.NewGauge(backendOpenConnsGauge...),
-		backendRetriesCounter:          multi.NewCounter(backendRetriesCounter...),
-		backendServerUpGauge:           multi.NewGauge(backendServerUpGauge...),
+		entryPointReqsCounter:          multi.NewCounter(entryPointReqsCounter...),
+		entryPointReqDurationHistogram: multi.NewHistogram(entryPointReqDurationHistogram...),
+		entryPointOpenConnsGauge:       multi.NewGauge(entryPointOpenConnsGauge...),
+		serviceReqsCounter:             multi.NewCounter(serviceReqsCounter...),
+		serviceReqDurationHistogram:    multi.NewHistogram(serviceReqDurationHistogram...),
+		serviceOpenConnsGauge:          multi.NewGauge(serviceOpenConnsGauge...),
+		serviceRetriesCounter:          multi.NewCounter(serviceRetriesCounter...),
+		serviceServerUpGauge:           multi.NewGauge(serviceServerUpGauge...),
 	}
 }
 
 type standardRegistry struct {
-	enabled                        bool
+	epEnabled                      bool
+	svcEnabled                     bool
 	configReloadsCounter           metrics.Counter
 	configReloadsFailureCounter    metrics.Counter
 	lastConfigReloadSuccessGauge   metrics.Gauge
 	lastConfigReloadFailureGauge   metrics.Gauge
-	entrypointReqsCounter          metrics.Counter
-	entrypointReqDurationHistogram metrics.Histogram
-	entrypointOpenConnsGauge       metrics.Gauge
-	backendReqsCounter             metrics.Counter
-	backendReqDurationHistogram    metrics.Histogram
-	backendOpenConnsGauge          metrics.Gauge
-	backendRetriesCounter          metrics.Counter
-	backendServerUpGauge           metrics.Gauge
+	entryPointReqsCounter          metrics.Counter
+	entryPointReqDurationHistogram metrics.Histogram
+	entryPointOpenConnsGauge       metrics.Gauge
+	serviceReqsCounter             metrics.Counter
+	serviceReqDurationHistogram    metrics.Histogram
+	serviceOpenConnsGauge          metrics.Gauge
+	serviceRetriesCounter          metrics.Counter
+	serviceServerUpGauge           metrics.Gauge
 }
 
-func (r *standardRegistry) IsEnabled() bool {
-	return r.enabled
+func (r *standardRegistry) IsEpEnabled() bool {
+	return r.epEnabled
+}
+
+func (r *standardRegistry) IsSvcEnabled() bool {
+	return r.svcEnabled
 }
 
 func (r *standardRegistry) ConfigReloadsCounter() metrics.Counter {
@@ -144,34 +152,34 @@ func (r *standardRegistry) LastConfigReloadFailureGauge() metrics.Gauge {
 	return r.lastConfigReloadFailureGauge
 }
 
-func (r *standardRegistry) EntrypointReqsCounter() metrics.Counter {
-	return r.entrypointReqsCounter
+func (r *standardRegistry) EntryPointReqsCounter() metrics.Counter {
+	return r.entryPointReqsCounter
 }
 
-func (r *standardRegistry) EntrypointReqDurationHistogram() metrics.Histogram {
-	return r.entrypointReqDurationHistogram
+func (r *standardRegistry) EntryPointReqDurationHistogram() metrics.Histogram {
+	return r.entryPointReqDurationHistogram
 }
 
-func (r *standardRegistry) EntrypointOpenConnsGauge() metrics.Gauge {
-	return r.entrypointOpenConnsGauge
+func (r *standardRegistry) EntryPointOpenConnsGauge() metrics.Gauge {
+	return r.entryPointOpenConnsGauge
 }
 
-func (r *standardRegistry) BackendReqsCounter() metrics.Counter {
-	return r.backendReqsCounter
+func (r *standardRegistry) ServiceReqsCounter() metrics.Counter {
+	return r.serviceReqsCounter
 }
 
-func (r *standardRegistry) BackendReqDurationHistogram() metrics.Histogram {
-	return r.backendReqDurationHistogram
+func (r *standardRegistry) ServiceReqDurationHistogram() metrics.Histogram {
+	return r.serviceReqDurationHistogram
 }
 
-func (r *standardRegistry) BackendOpenConnsGauge() metrics.Gauge {
-	return r.backendOpenConnsGauge
+func (r *standardRegistry) ServiceOpenConnsGauge() metrics.Gauge {
+	return r.serviceOpenConnsGauge
 }
 
-func (r *standardRegistry) BackendRetriesCounter() metrics.Counter {
-	return r.backendRetriesCounter
+func (r *standardRegistry) ServiceRetriesCounter() metrics.Counter {
+	return r.serviceRetriesCounter
 }
 
-func (r *standardRegistry) BackendServerUpGauge() metrics.Gauge {
-	return r.backendServerUpGauge
+func (r *standardRegistry) ServiceServerUpGauge() metrics.Gauge {
+	return r.serviceServerUpGauge
 }

pkg/metrics/metrics_test.go

@@ -11,14 +11,14 @@ func TestNewMultiRegistry(t *testing.T) {
 	registries := []Registry{newCollectingRetryMetrics(), newCollectingRetryMetrics()}
 	registry := NewMultiRegistry(registries)
 
-	registry.BackendReqsCounter().With("key", "requests").Add(1)
-	registry.BackendReqDurationHistogram().With("key", "durations").Observe(2)
-	registry.BackendRetriesCounter().With("key", "retries").Add(3)
+	registry.ServiceReqsCounter().With("key", "requests").Add(1)
+	registry.ServiceReqDurationHistogram().With("key", "durations").Observe(2)
+	registry.ServiceRetriesCounter().With("key", "retries").Add(3)
 
 	for _, collectingRegistry := range registries {
-		cReqsCounter := collectingRegistry.BackendReqsCounter().(*counterMock)
-		cReqDurationHistogram := collectingRegistry.BackendReqDurationHistogram().(*histogramMock)
-		cRetriesCounter := collectingRegistry.BackendRetriesCounter().(*counterMock)
+		cReqsCounter := collectingRegistry.ServiceReqsCounter().(*counterMock)
+		cReqDurationHistogram := collectingRegistry.ServiceReqDurationHistogram().(*histogramMock)
+		cRetriesCounter := collectingRegistry.ServiceRetriesCounter().(*counterMock)
 
 		wantCounterValue := float64(1)
 		if cReqsCounter.counterValue != wantCounterValue {
@@ -41,9 +41,9 @@ func TestNewMultiRegistry(t *testing.T) {
 
 func newCollectingRetryMetrics() Registry {
 	return &standardRegistry{
-		backendReqsCounter:          &counterMock{},
-		backendReqDurationHistogram: &histogramMock{},
-		backendRetriesCounter:       &counterMock{},
+		serviceReqsCounter:          &counterMock{},
+		serviceReqDurationHistogram: &histogramMock{},
+		serviceRetriesCounter:       &counterMock{},
 	}
 }
 

pkg/metrics/prometheus.go

@@ -2,6 +2,7 @@ package metrics
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"sort"
 	"strings"
@@ -28,43 +29,45 @@ const (
 	configLastReloadSuccessName    = metricConfigPrefix + "last_reload_success"
 	configLastReloadFailureName    = metricConfigPrefix + "last_reload_failure"
 
-	// entrypoint
+	// entry point
 	metricEntryPointPrefix    = MetricNamePrefix + "entrypoint_"
-	entrypointReqsTotalName   = metricEntryPointPrefix + "requests_total"
-	entrypointReqDurationName = metricEntryPointPrefix + "request_duration_seconds"
-	entrypointOpenConnsName   = metricEntryPointPrefix + "open_connections"
+	entryPointReqsTotalName   = metricEntryPointPrefix + "requests_total"
+	entryPointReqDurationName = metricEntryPointPrefix + "request_duration_seconds"
+	entryPointOpenConnsName   = metricEntryPointPrefix + "open_connections"
 
-	// backend level.
+	// service level.
 
-	// MetricBackendPrefix prefix of all backend metric names
-	MetricBackendPrefix     = MetricNamePrefix + "backend_"
-	backendReqsTotalName    = MetricBackendPrefix + "requests_total"
-	backendReqDurationName  = MetricBackendPrefix + "request_duration_seconds"
-	backendOpenConnsName    = MetricBackendPrefix + "open_connections"
-	backendRetriesTotalName = MetricBackendPrefix + "retries_total"
-	backendServerUpName     = MetricBackendPrefix + "server_up"
+	// MetricServicePrefix prefix of all service metric names
+	MetricServicePrefix     = MetricNamePrefix + "service_"
+	serviceReqsTotalName    = MetricServicePrefix + "requests_total"
+	serviceReqDurationName  = MetricServicePrefix + "request_duration_seconds"
+	serviceOpenConnsName    = MetricServicePrefix + "open_connections"
+	serviceRetriesTotalName = MetricServicePrefix + "retries_total"
+	serviceServerUpName     = MetricServicePrefix + "server_up"
 )
 
 // promState holds all metric state internally and acts as the only Collector we register for Prometheus.
 //
 // This enables control to remove metrics that belong to outdated configuration.
 // As an example why this is required, consider Traefik learns about a new service.
-// It populates the 'traefik_server_backend_up' metric for it with a value of 1 (alive).
-// When the backend is undeployed now the metric is still there in the client library
+// It populates the 'traefik_server_service_up' metric for it with a value of 1 (alive).
+// When the service is undeployed now the metric is still there in the client library
 // and will be returned on the metrics endpoint until Traefik would be restarted.
 //
 // To solve this problem promState keeps track of Traefik's dynamic configuration.
-// Metrics that "belong" to a dynamic configuration part like backends or entrypoints
+// Metrics that "belong" to a dynamic configuration part like services or entryPoints
 // are removed after they were scraped at least once when the corresponding object
 // doesn't exist anymore.
 var promState = newPrometheusState()
 
+var promRegistry = stdprometheus.NewRegistry()
+
 // PrometheusHandler exposes Prometheus routes.
 type PrometheusHandler struct{}
 
 // Append adds Prometheus routes on a router.
 func (h PrometheusHandler) Append(router *mux.Router) {
-	router.Methods(http.MethodGet).Path("/metrics").Handler(promhttp.Handler())
+	router.Methods(http.MethodGet).Path("/metrics").Handler(promhttp.HandlerFor(promRegistry, promhttp.HandlerOpts{}))
 }
 
 // RegisterPrometheus registers all Prometheus metrics.
@@ -72,6 +75,17 @@ func (h PrometheusHandler) Append(router *mux.Router) {
 func RegisterPrometheus(ctx context.Context, config *types.Prometheus) Registry {
 	standardRegistry := initStandardRegistry(config)
 
+	if err := promRegistry.Register(stdprometheus.NewProcessCollector(stdprometheus.ProcessCollectorOpts{})); err != nil {
+		if _, ok := err.(stdprometheus.AlreadyRegisteredError); !ok {
+			log.FromContext(ctx).Warn("ProcessCollector is already registered")
+		}
+	}
+	if err := promRegistry.Register(stdprometheus.NewGoCollector()); err != nil {
+		if _, ok := err.(stdprometheus.AlreadyRegisteredError); !ok {
+			log.FromContext(ctx).Warn("GoCollector is already registered")
+		}
+	}
+
 	if !registerPromState(ctx) {
 		return nil
 	}
@@ -106,76 +120,89 @@ func initStandardRegistry(config *types.Prometheus) Registry {
 		Help: "Last config reload failure",
 	}, []string{})
 
-	entrypointReqs := newCounterFrom(promState.collectors, stdprometheus.CounterOpts{
-		Name: entrypointReqsTotalName,
-		Help: "How many HTTP requests processed on an entrypoint, partitioned by status code, protocol, and method.",
-	}, []string{"code", "method", "protocol", "entrypoint"})
-	entrypointReqDurations := newHistogramFrom(promState.collectors, stdprometheus.HistogramOpts{
-		Name:    entrypointReqDurationName,
-		Help:    "How long it took to process the request on an entrypoint, partitioned by status code, protocol, and method.",
-		Buckets: buckets,
-	}, []string{"code", "method", "protocol", "entrypoint"})
-	entrypointOpenConns := newGaugeFrom(promState.collectors, stdprometheus.GaugeOpts{
-		Name: entrypointOpenConnsName,
-		Help: "How many open connections exist on an entrypoint, partitioned by method and protocol.",
-	}, []string{"method", "protocol", "entrypoint"})
-
-	backendReqs := newCounterFrom(promState.collectors, stdprometheus.CounterOpts{
-		Name: backendReqsTotalName,
-		Help: "How many HTTP requests processed on a backend, partitioned by status code, protocol, and method.",
-	}, []string{"code", "method", "protocol", "backend"})
-	backendReqDurations := newHistogramFrom(promState.collectors, stdprometheus.HistogramOpts{
-		Name:    backendReqDurationName,
-		Help:    "How long it took to process the request on a backend, partitioned by status code, protocol, and method.",
-		Buckets: buckets,
-	}, []string{"code", "method", "protocol", "backend"})
-	backendOpenConns := newGaugeFrom(promState.collectors, stdprometheus.GaugeOpts{
-		Name: backendOpenConnsName,
-		Help: "How many open connections exist on a backend, partitioned by method and protocol.",
-	}, []string{"method", "protocol", "backend"})
-	backendRetries := newCounterFrom(promState.collectors, stdprometheus.CounterOpts{
-		Name: backendRetriesTotalName,
-		Help: "How many request retries happened on a backend.",
-	}, []string{"backend"})
-	backendServerUp := newGaugeFrom(promState.collectors, stdprometheus.GaugeOpts{
-		Name: backendServerUpName,
-		Help: "Backend server is up, described by gauge value of 0 or 1.",
-	}, []string{"backend", "url"})
-
 	promState.describers = []func(chan<- *stdprometheus.Desc){
 		configReloads.cv.Describe,
 		configReloadsFailures.cv.Describe,
 		lastConfigReloadSuccess.gv.Describe,
 		lastConfigReloadFailure.gv.Describe,
-		entrypointReqs.cv.Describe,
-		entrypointReqDurations.hv.Describe,
-		entrypointOpenConns.gv.Describe,
-		backendReqs.cv.Describe,
-		backendReqDurations.hv.Describe,
-		backendOpenConns.gv.Describe,
-		backendRetries.cv.Describe,
-		backendServerUp.gv.Describe,
 	}
 
-	return &standardRegistry{
-		enabled:                        true,
-		configReloadsCounter:           configReloads,
-		configReloadsFailureCounter:    configReloadsFailures,
-		lastConfigReloadSuccessGauge:   lastConfigReloadSuccess,
-		lastConfigReloadFailureGauge:   lastConfigReloadFailure,
-		entrypointReqsCounter:          entrypointReqs,
-		entrypointReqDurationHistogram: entrypointReqDurations,
-		entrypointOpenConnsGauge:       entrypointOpenConns,
-		backendReqsCounter:             backendReqs,
-		backendReqDurationHistogram:    backendReqDurations,
-		backendOpenConnsGauge:          backendOpenConns,
-		backendRetriesCounter:          backendRetries,
-		backendServerUpGauge:           backendServerUp,
+	reg := &standardRegistry{
+		epEnabled:                    config.AddEntryPointsLabels,
+		svcEnabled:                   config.AddServicesLabels,
+		configReloadsCounter:         configReloads,
+		configReloadsFailureCounter:  configReloadsFailures,
+		lastConfigReloadSuccessGauge: lastConfigReloadSuccess,
+		lastConfigReloadFailureGauge: lastConfigReloadFailure,
 	}
+
+	if config.AddEntryPointsLabels {
+		entryPointReqs := newCounterFrom(promState.collectors, stdprometheus.CounterOpts{
+			Name: entryPointReqsTotalName,
+			Help: "How many HTTP requests processed on an entrypoint, partitioned by status code, protocol, and method.",
+		}, []string{"code", "method", "protocol", "entrypoint"})
+		entryPointReqDurations := newHistogramFrom(promState.collectors, stdprometheus.HistogramOpts{
+			Name:    entryPointReqDurationName,
+			Help:    "How long it took to process the request on an entrypoint, partitioned by status code, protocol, and method.",
+			Buckets: buckets,
+		}, []string{"code", "method", "protocol", "entrypoint"})
+		entryPointOpenConns := newGaugeFrom(promState.collectors, stdprometheus.GaugeOpts{
+			Name: entryPointOpenConnsName,
+			Help: "How many open connections exist on an entrypoint, partitioned by method and protocol.",
+		}, []string{"method", "protocol", "entrypoint"})
+
+		promState.describers = append(promState.describers, []func(chan<- *stdprometheus.Desc){
+			entryPointReqs.cv.Describe,
+			entryPointReqDurations.hv.Describe,
+			entryPointOpenConns.gv.Describe,
+		}...)
+		reg.entryPointReqsCounter = entryPointReqs
+		reg.entryPointReqDurationHistogram = entryPointReqDurations
+		reg.entryPointOpenConnsGauge = entryPointOpenConns
+	}
+	if config.AddServicesLabels {
+		serviceReqs := newCounterFrom(promState.collectors, stdprometheus.CounterOpts{
+			Name: serviceReqsTotalName,
+			Help: "How many HTTP requests processed on a service, partitioned by status code, protocol, and method.",
+		}, []string{"code", "method", "protocol", "service"})
+		serviceReqDurations := newHistogramFrom(promState.collectors, stdprometheus.HistogramOpts{
+			Name:    serviceReqDurationName,
+			Help:    "How long it took to process the request on a service, partitioned by status code, protocol, and method.",
+			Buckets: buckets,
+		}, []string{"code", "method", "protocol", "service"})
+		serviceOpenConns := newGaugeFrom(promState.collectors, stdprometheus.GaugeOpts{
+			Name: serviceOpenConnsName,
+			Help: "How many open connections exist on a service, partitioned by method and protocol.",
+		}, []string{"method", "protocol", "service"})
+		serviceRetries := newCounterFrom(promState.collectors, stdprometheus.CounterOpts{
+			Name: serviceRetriesTotalName,
+			Help: "How many request retries happened on a service.",
+		}, []string{"service"})
+		serviceServerUp := newGaugeFrom(promState.collectors, stdprometheus.GaugeOpts{
+			Name: serviceServerUpName,
+			Help: "service server is up, described by gauge value of 0 or 1.",
+		}, []string{"service", "url"})
+
+		promState.describers = append(promState.describers, []func(chan<- *stdprometheus.Desc){
+			serviceReqs.cv.Describe,
+			serviceReqDurations.hv.Describe,
+			serviceOpenConns.gv.Describe,
+			serviceRetries.cv.Describe,
+			serviceServerUp.gv.Describe,
+		}...)
+
+		reg.serviceReqsCounter = serviceReqs
+		reg.serviceReqDurationHistogram = serviceReqDurations
+		reg.serviceOpenConnsGauge = serviceOpenConns
+		reg.serviceRetriesCounter = serviceRetries
+		reg.serviceServerUpGauge = serviceServerUp
+	}
+
+	return reg
 }
 
 func registerPromState(ctx context.Context) bool {
-	if err := stdprometheus.Register(promState); err != nil {
+	if err := promRegistry.Register(promState); err != nil {
 		logger := log.FromContext(ctx)
 		if _, ok := err.(stdprometheus.AlreadyRegisteredError); !ok {
 			logger.Errorf("Unable to register Traefik to Prometheus: %v", err)
@@ -189,24 +216,24 @@ func registerPromState(ctx context.Context) bool {
 // OnConfigurationUpdate receives the current configuration from Traefik.
 // It then converts the configuration to the optimized package internal format
 // and sets it to the promState.
-func OnConfigurationUpdate(configurations dynamic.Configurations) {
+func OnConfigurationUpdate(dynConf dynamic.Configurations, entryPoints []string) {
 	dynamicConfig := newDynamicConfig()
 
-	// FIXME metrics
-	// for _, config := range configurations {
-	// 	for _, frontend := range config.Frontends {
-	// 		for _, entrypointName := range frontend.EntryPoints {
-	// 			dynamicConfig.entrypoints[entrypointName] = true
-	// 		}
-	// 	}
-	//
-	// 	for backendName, backend := range config.Backends {
-	// 		dynamicConfig.backends[backendName] = make(map[string]bool)
-	// 		for _, server := range backend.Servers {
-	// 			dynamicConfig.backends[backendName][server.URL] = true
-	// 		}
-	// 	}
-	// }
+	for _, value := range entryPoints {
+		dynamicConfig.entryPoints[value] = true
+	}
+	for key, config := range dynConf {
+		for name := range config.HTTP.Routers {
+			dynamicConfig.routers[fmt.Sprintf("%s@%s", name, key)] = true
+		}
+
+		for serviceName, service := range config.HTTP.Services {
+			dynamicConfig.services[fmt.Sprintf("%s@%s", serviceName, key)] = make(map[string]bool)
+			for _, server := range service.LoadBalancer.Servers {
+				dynamicConfig.services[fmt.Sprintf("%s@%s", serviceName, key)][server.URL] = true
+			}
+		}
+	}
 
 	promState.SetDynamicConfig(dynamicConfig)
 }
@@ -279,15 +306,15 @@ func (ps *prometheusState) Collect(ch chan<- stdprometheus.Metric) {
 func (ps *prometheusState) isOutdated(collector *collector) bool {
 	labels := collector.labels
 
-	if entrypointName, ok := labels["entrypoint"]; ok && !ps.dynamicConfig.hasEntrypoint(entrypointName) {
+	if entrypointName, ok := labels["entrypoint"]; ok && !ps.dynamicConfig.hasEntryPoint(entrypointName) {
 		return true
 	}
 
-	if backendName, ok := labels["backend"]; ok {
-		if !ps.dynamicConfig.hasBackend(backendName) {
+	if serviceName, ok := labels["service"]; ok {
+		if !ps.dynamicConfig.hasService(serviceName) {
 			return true
 		}
-		if url, ok := labels["url"]; ok && !ps.dynamicConfig.hasServerURL(backendName, url) {
+		if url, ok := labels["url"]; ok && !ps.dynamicConfig.hasServerURL(serviceName, url) {
 			return true
 		}
 	}
@@ -297,33 +324,35 @@ func (ps *prometheusState) isOutdated(collector *collector) bool {
 
 func newDynamicConfig() *dynamicConfig {
 	return &dynamicConfig{
-		entrypoints: make(map[string]bool),
-		backends:    make(map[string]map[string]bool),
+		entryPoints: make(map[string]bool),
+		routers:     make(map[string]bool),
+		services:    make(map[string]map[string]bool),
 	}
 }
 
-// dynamicConfig holds the current configuration for entrypoints, backends,
+// dynamicConfig holds the current configuration for entryPoints, services,
 // and server URLs in an optimized way to check for existence. This provides
 // a performant way to check whether the collected metrics belong to the
 // current configuration or to an outdated one.
 type dynamicConfig struct {
-	entrypoints map[string]bool
-	backends    map[string]map[string]bool
+	entryPoints map[string]bool
+	routers     map[string]bool
+	services    map[string]map[string]bool
 }
 
-func (d *dynamicConfig) hasEntrypoint(entrypointName string) bool {
-	_, ok := d.entrypoints[entrypointName]
+func (d *dynamicConfig) hasEntryPoint(entrypointName string) bool {
+	_, ok := d.entryPoints[entrypointName]
 	return ok
 }
 
-func (d *dynamicConfig) hasBackend(backendName string) bool {
-	_, ok := d.backends[backendName]
+func (d *dynamicConfig) hasService(serviceName string) bool {
+	_, ok := d.services[serviceName]
 	return ok
 }
 
-func (d *dynamicConfig) hasServerURL(backendName, serverURL string) bool {
-	if backend, hasBackend := d.backends[backendName]; hasBackend {
-		_, ok := backend[serverURL]
+func (d *dynamicConfig) hasServerURL(serviceName, serverURL string) bool {
+	if service, hasService := d.services[serviceName]; hasService {
+		_, ok := service[serverURL]
 		return ok
 	}
 	return false
@@ -479,7 +508,7 @@ func (h *histogram) Observe(value float64) {
 	labels := h.labelNamesValues.ToLabels()
 	collector := h.hv.With(labels)
 	collector.Observe(value)
-	h.collectors <- newCollector(h.name, labels, collector, func() {
+	h.collectors <- newCollector(h.name, labels, h.hv, func() {
 		h.hv.Delete(labels)
 	})
 }

pkg/metrics/prometheus_test.go

@@ -30,61 +30,61 @@ func TestRegisterPromState(t *testing.T) {
 		{
 			desc:                 "Register once",
 			prometheusSlice:      []*types.Prometheus{{}},
-			expectedNbRegistries: 1,
 			initPromState:        true,
+			unregisterPromState:  false,
+			expectedNbRegistries: 1,
 		},
 		{
 			desc:                 "Register once with no promState init",
 			prometheusSlice:      []*types.Prometheus{{}},
-			expectedNbRegistries: 0,
+			initPromState:        false,
+			unregisterPromState:  false,
+			expectedNbRegistries: 1,
 		},
 		{
 			desc:                 "Register twice",
 			prometheusSlice:      []*types.Prometheus{{}, {}},
-			expectedNbRegistries: 2,
 			initPromState:        true,
+			unregisterPromState:  false,
+			expectedNbRegistries: 2,
 		},
 		{
 			desc:                 "Register twice with no promstate init",
 			prometheusSlice:      []*types.Prometheus{{}, {}},
-			expectedNbRegistries: 0,
+			initPromState:        false,
+			unregisterPromState:  false,
+			expectedNbRegistries: 2,
 		},
 		{
 			desc:                 "Register twice with unregister",
 			prometheusSlice:      []*types.Prometheus{{}, {}},
+			initPromState:        true,
 			unregisterPromState:  true,
 			expectedNbRegistries: 2,
-			initPromState:        true,
-		},
-		{
-			desc:                 "Register twice with unregister but no promstate init",
-			prometheusSlice:      []*types.Prometheus{{}, {}},
-			unregisterPromState:  true,
-			expectedNbRegistries: 0,
 		},
 	}
 
 	for _, test := range testCases {
-		actualNbRegistries := 0
-		for _, prom := range test.prometheusSlice {
-			if test.initPromState {
-				initStandardRegistry(prom)
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			actualNbRegistries := 0
+			for _, prom := range test.prometheusSlice {
+				if test.initPromState {
+					initStandardRegistry(prom)
+				}
+				if registerPromState(context.Background()) {
+					actualNbRegistries++
+				}
+				if test.unregisterPromState {
+					promRegistry.Unregister(promState)
+				}
+
+				promState.reset()
 			}
 
-			if registerPromState(context.Background()) {
-				actualNbRegistries++
-			}
-
-			if test.unregisterPromState {
-				prometheus.Unregister(promState)
-			}
-
-			promState.reset()
-		}
-
-		prometheus.Unregister(promState)
-
-		assert.Equal(t, test.expectedNbRegistries, actualNbRegistries)
+			promRegistry.Unregister(promState)
+			assert.Equal(t, test.expectedNbRegistries, actualNbRegistries)
+		})
 	}
 }
 
@@ -99,13 +99,15 @@ func (ps *prometheusState) reset() {
 }
 
 func TestPrometheus(t *testing.T) {
+	promState = newPrometheusState()
+	promRegistry = prometheus.NewRegistry()
 	// Reset state of global promState.
 	defer promState.reset()
 
-	prometheusRegistry := RegisterPrometheus(context.Background(), &types.Prometheus{})
-	defer prometheus.Unregister(promState)
+	prometheusRegistry := RegisterPrometheus(context.Background(), &types.Prometheus{AddEntryPointsLabels: true, AddServicesLabels: true})
+	defer promRegistry.Unregister(promState)
 
-	if !prometheusRegistry.IsEnabled() {
+	if !prometheusRegistry.IsEpEnabled() || !prometheusRegistry.IsSvcEnabled() {
 		t.Errorf("PrometheusRegistry should return true for IsEnabled()")
 	}
 
@@ -115,44 +117,44 @@ func TestPrometheus(t *testing.T) {
 	prometheusRegistry.LastConfigReloadFailureGauge().Set(float64(time.Now().Unix()))
 
 	prometheusRegistry.
-		EntrypointReqsCounter().
+		EntryPointReqsCounter().
 		With("code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http", "entrypoint", "http").
 		Add(1)
 	prometheusRegistry.
-		EntrypointReqDurationHistogram().
+		EntryPointReqDurationHistogram().
 		With("code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http", "entrypoint", "http").
 		Observe(1)
 	prometheusRegistry.
-		EntrypointOpenConnsGauge().
+		EntryPointOpenConnsGauge().
 		With("method", http.MethodGet, "protocol", "http", "entrypoint", "http").
 		Set(1)
 
 	prometheusRegistry.
-		BackendReqsCounter().
-		With("backend", "backend1", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http").
+		ServiceReqsCounter().
+		With("service", "service1", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http").
 		Add(1)
 	prometheusRegistry.
-		BackendReqDurationHistogram().
-		With("backend", "backend1", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http").
+		ServiceReqDurationHistogram().
+		With("service", "service1", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http").
 		Observe(10000)
 	prometheusRegistry.
-		BackendOpenConnsGauge().
-		With("backend", "backend1", "method", http.MethodGet, "protocol", "http").
+		ServiceOpenConnsGauge().
+		With("service", "service1", "method", http.MethodGet, "protocol", "http").
 		Set(1)
 	prometheusRegistry.
-		BackendRetriesCounter().
-		With("backend", "backend1").
+		ServiceRetriesCounter().
+		With("service", "service1").
 		Add(1)
 	prometheusRegistry.
-		BackendServerUpGauge().
-		With("backend", "backend1", "url", "http://127.0.0.10:80").
+		ServiceServerUpGauge().
+		With("service", "service1", "url", "http://127.0.0.10:80").
 		Set(1)
 
 	delayForTrackingCompletion()
 
 	metricsFamilies := mustScrape()
 
-	tests := []struct {
+	testCases := []struct {
 		name   string
 		labels map[string]string
 		assert func(*dto.MetricFamily)
@@ -174,107 +176,111 @@ func TestPrometheus(t *testing.T) {
 			assert: buildTimestampAssert(t, configLastReloadFailureName),
 		},
 		{
-			name: entrypointReqsTotalName,
+			name: entryPointReqsTotalName,
 			labels: map[string]string{
 				"code":       "200",
 				"method":     http.MethodGet,
 				"protocol":   "http",
 				"entrypoint": "http",
 			},
-			assert: buildCounterAssert(t, entrypointReqsTotalName, 1),
+			assert: buildCounterAssert(t, entryPointReqsTotalName, 1),
 		},
 		{
-			name: entrypointReqDurationName,
+			name: entryPointReqDurationName,
 			labels: map[string]string{
 				"code":       "200",
 				"method":     http.MethodGet,
 				"protocol":   "http",
 				"entrypoint": "http",
 			},
-			assert: buildHistogramAssert(t, entrypointReqDurationName, 1),
+			assert: buildHistogramAssert(t, entryPointReqDurationName, 1),
 		},
 		{
-			name: entrypointOpenConnsName,
+			name: entryPointOpenConnsName,
 			labels: map[string]string{
 				"method":     http.MethodGet,
 				"protocol":   "http",
 				"entrypoint": "http",
 			},
-			assert: buildGaugeAssert(t, entrypointOpenConnsName, 1),
+			assert: buildGaugeAssert(t, entryPointOpenConnsName, 1),
 		},
 		{
-			name: backendReqsTotalName,
+			name: serviceReqsTotalName,
 			labels: map[string]string{
 				"code":     "200",
 				"method":   http.MethodGet,
 				"protocol": "http",
-				"backend":  "backend1",
+				"service":  "service1",
 			},
-			assert: buildCounterAssert(t, backendReqsTotalName, 1),
+			assert: buildCounterAssert(t, serviceReqsTotalName, 1),
 		},
 		{
-			name: backendReqDurationName,
+			name: serviceReqDurationName,
 			labels: map[string]string{
 				"code":     "200",
 				"method":   http.MethodGet,
 				"protocol": "http",
-				"backend":  "backend1",
+				"service":  "service1",
 			},
-			assert: buildHistogramAssert(t, backendReqDurationName, 1),
+			assert: buildHistogramAssert(t, serviceReqDurationName, 1),
 		},
 		{
-			name: backendOpenConnsName,
+			name: serviceOpenConnsName,
 			labels: map[string]string{
 				"method":   http.MethodGet,
 				"protocol": "http",
-				"backend":  "backend1",
+				"service":  "service1",
 			},
-			assert: buildGaugeAssert(t, backendOpenConnsName, 1),
+			assert: buildGaugeAssert(t, serviceOpenConnsName, 1),
 		},
 		{
-			name: backendRetriesTotalName,
+			name: serviceRetriesTotalName,
 			labels: map[string]string{
-				"backend": "backend1",
+				"service": "service1",
 			},
-			assert: buildGreaterThanCounterAssert(t, backendRetriesTotalName, 1),
+			assert: buildGreaterThanCounterAssert(t, serviceRetriesTotalName, 1),
 		},
 		{
-			name: backendServerUpName,
+			name: serviceServerUpName,
 			labels: map[string]string{
-				"backend": "backend1",
+				"service": "service1",
 				"url":     "http://127.0.0.10:80",
 			},
-			assert: buildGaugeAssert(t, backendServerUpName, 1),
+			assert: buildGaugeAssert(t, serviceServerUpName, 1),
 		},
 	}
 
-	for _, test := range tests {
-		family := findMetricFamily(test.name, metricsFamilies)
-		if family == nil {
-			t.Errorf("gathered metrics do not contain %q", test.name)
-			continue
-		}
-		for _, label := range family.Metric[0].Label {
-			val, ok := test.labels[*label.Name]
-			if !ok {
-				t.Errorf("%q metric contains unexpected label %q", test.name, *label.Name)
-			} else if val != *label.Value {
-				t.Errorf("label %q in metric %q has wrong value %q, expected %q", *label.Name, test.name, *label.Value, val)
+	for _, test := range testCases {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			family := findMetricFamily(test.name, metricsFamilies)
+			if family == nil {
+				t.Errorf("gathered metrics do not contain %q", test.name)
+				return
 			}
-		}
-		test.assert(family)
+
+			for _, label := range family.Metric[0].Label {
+				val, ok := test.labels[*label.Name]
+				if !ok {
+					t.Errorf("%q metric contains unexpected label %q", test.name, *label.Name)
+				} else if val != *label.Value {
+					t.Errorf("label %q in metric %q has wrong value %q, expected %q", *label.Name, test.name, *label.Value, val)
+				}
+			}
+			test.assert(family)
+		})
+
 	}
 }
 
 func TestPrometheusMetricRemoval(t *testing.T) {
-	// FIXME metrics
-	t.Skip("waiting for metrics")
-
+	promState = newPrometheusState()
+	promRegistry = prometheus.NewRegistry()
 	// Reset state of global promState.
 	defer promState.reset()
 
-	prometheusRegistry := RegisterPrometheus(context.Background(), &types.Prometheus{})
-	defer prometheus.Unregister(promState)
+	prometheusRegistry := RegisterPrometheus(context.Background(), &types.Prometheus{AddEntryPointsLabels: true, AddServicesLabels: true})
+	defer promRegistry.Unregister(promState)
 
 	configurations := make(dynamic.Configurations)
 	configurations["providerName"] = &dynamic.Configuration{
@@ -289,78 +295,78 @@ func TestPrometheusMetricRemoval(t *testing.T) {
 		),
 	}
 
-	OnConfigurationUpdate(configurations)
+	OnConfigurationUpdate(configurations, []string{"entrypoint1"})
 
 	// Register some metrics manually that are not part of the active configuration.
 	// Those metrics should be part of the /metrics output on the first scrape but
 	// should be removed after that scrape.
 	prometheusRegistry.
-		EntrypointReqsCounter().
+		EntryPointReqsCounter().
 		With("entrypoint", "entrypoint2", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http").
 		Add(1)
 	prometheusRegistry.
-		BackendReqsCounter().
-		With("backend", "backend2", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http").
+		ServiceReqsCounter().
+		With("service", "service2", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http").
 		Add(1)
 	prometheusRegistry.
-		BackendServerUpGauge().
-		With("backend", "backend1", "url", "http://localhost:9999").
+		ServiceServerUpGauge().
+		With("service", "service1", "url", "http://localhost:9999").
 		Set(1)
 
 	delayForTrackingCompletion()
 
-	assertMetricsExist(t, mustScrape(), entrypointReqsTotalName, backendReqsTotalName, backendServerUpName)
-	assertMetricsAbsent(t, mustScrape(), entrypointReqsTotalName, backendReqsTotalName, backendServerUpName)
+	assertMetricsExist(t, mustScrape(), entryPointReqsTotalName, serviceReqsTotalName, serviceServerUpName)
+	assertMetricsAbsent(t, mustScrape(), entryPointReqsTotalName, serviceReqsTotalName, serviceServerUpName)
 
 	// To verify that metrics belonging to active configurations are not removed
 	// here the counter examples.
 	prometheusRegistry.
-		EntrypointReqsCounter().
+		EntryPointReqsCounter().
 		With("entrypoint", "entrypoint1", "code", strconv.Itoa(http.StatusOK), "method", http.MethodGet, "protocol", "http").
 		Add(1)
 
 	delayForTrackingCompletion()
 
-	assertMetricsExist(t, mustScrape(), entrypointReqsTotalName)
-	assertMetricsExist(t, mustScrape(), entrypointReqsTotalName)
+	assertMetricsExist(t, mustScrape(), entryPointReqsTotalName)
+	assertMetricsExist(t, mustScrape(), entryPointReqsTotalName)
 }
 
 func TestPrometheusRemovedMetricsReset(t *testing.T) {
 	// Reset state of global promState.
 	defer promState.reset()
 
-	prometheusRegistry := RegisterPrometheus(context.Background(), &types.Prometheus{})
-	defer prometheus.Unregister(promState)
+	prometheusRegistry := RegisterPrometheus(context.Background(), &types.Prometheus{AddEntryPointsLabels: true, AddServicesLabels: true})
+	defer promRegistry.Unregister(promState)
 
 	labelNamesValues := []string{
-		"backend", "backend",
+		"service", "service",
 		"code", strconv.Itoa(http.StatusOK),
 		"method", http.MethodGet,
 		"protocol", "http",
 	}
 	prometheusRegistry.
-		BackendReqsCounter().
+		ServiceReqsCounter().
 		With(labelNamesValues...).
 		Add(3)
 
 	delayForTrackingCompletion()
 
 	metricsFamilies := mustScrape()
-	assertCounterValue(t, 3, findMetricFamily(backendReqsTotalName, metricsFamilies), labelNamesValues...)
+	assertCounterValue(t, 3, findMetricFamily(serviceReqsTotalName, metricsFamilies), labelNamesValues...)
 
 	// There is no dynamic configuration and so this metric will be deleted
 	// after the first scrape.
-	assertMetricsAbsent(t, mustScrape(), backendReqsTotalName)
+	assertMetricsAbsent(t, mustScrape(), serviceReqsTotalName)
 
 	prometheusRegistry.
-		BackendReqsCounter().
+		ServiceReqsCounter().
 		With(labelNamesValues...).
 		Add(1)
 
 	delayForTrackingCompletion()
 
 	metricsFamilies = mustScrape()
-	assertCounterValue(t, 1, findMetricFamily(backendReqsTotalName, metricsFamilies), labelNamesValues...)
+	assertCounterValue(t, 1, findMetricFamily(serviceReqsTotalName, metricsFamilies), labelNamesValues...)
 }
 
 // Tracking and gathering the metrics happens concurrently.
@@ -374,7 +380,7 @@ func delayForTrackingCompletion() {
 }
 
 func mustScrape() []*dto.MetricFamily {
-	families, err := prometheus.DefaultGatherer.Gather()
+	families, err := promRegistry.Gather()
 	if err != nil {
 		panic(fmt.Sprintf("could not gather metrics families: %s", err))
 	}

pkg/metrics/statsd.go

@@ -19,18 +19,18 @@ var statsdClient = statsd.New("traefik.", kitlog.LoggerFunc(func(keyvals ...inte
 var statsdTicker *time.Ticker
 
 const (
-	statsdMetricsBackendReqsName      = "backend.request.total"
-	statsdMetricsBackendLatencyName   = "backend.request.duration"
-	statsdRetriesTotalName            = "backend.retries.total"
+	statsdMetricsServiceReqsName      = "service.request.total"
+	statsdMetricsServiceLatencyName   = "service.request.duration"
+	statsdRetriesTotalName            = "service.retries.total"
 	statsdConfigReloadsName           = "config.reload.total"
 	statsdConfigReloadsFailureName    = statsdConfigReloadsName + ".failure"
 	statsdLastConfigReloadSuccessName = "config.reload.lastSuccessTimestamp"
 	statsdLastConfigReloadFailureName = "config.reload.lastFailureTimestamp"
-	statsdEntrypointReqsName          = "entrypoint.request.total"
-	statsdEntrypointReqDurationName   = "entrypoint.request.duration"
-	statsdEntrypointOpenConnsName     = "entrypoint.connections.open"
-	statsdOpenConnsName               = "backend.connections.open"
-	statsdServerUpName                = "backend.server.up"
+	statsdEntryPointReqsName          = "entrypoint.request.total"
+	statsdEntryPointReqDurationName   = "entrypoint.request.duration"
+	statsdEntryPointOpenConnsName     = "entrypoint.connections.open"
+	statsdOpenConnsName               = "service.connections.open"
+	statsdServerUpName                = "service.server.up"
 )
 
 // RegisterStatsd registers the metrics pusher if this didn't happen yet and creates a statsd Registry instance.
@@ -39,21 +39,30 @@ func RegisterStatsd(ctx context.Context, config *types.Statsd) Registry {
 		statsdTicker = initStatsdTicker(ctx, config)
 	}
 
-	return &standardRegistry{
-		enabled:                        true,
-		configReloadsCounter:           statsdClient.NewCounter(statsdConfigReloadsName, 1.0),
-		configReloadsFailureCounter:    statsdClient.NewCounter(statsdConfigReloadsFailureName, 1.0),
-		lastConfigReloadSuccessGauge:   statsdClient.NewGauge(statsdLastConfigReloadSuccessName),
-		lastConfigReloadFailureGauge:   statsdClient.NewGauge(statsdLastConfigReloadFailureName),
-		entrypointReqsCounter:          statsdClient.NewCounter(statsdEntrypointReqsName, 1.0),
-		entrypointReqDurationHistogram: statsdClient.NewTiming(statsdEntrypointReqDurationName, 1.0),
-		entrypointOpenConnsGauge:       statsdClient.NewGauge(statsdEntrypointOpenConnsName),
-		backendReqsCounter:             statsdClient.NewCounter(statsdMetricsBackendReqsName, 1.0),
-		backendReqDurationHistogram:    statsdClient.NewTiming(statsdMetricsBackendLatencyName, 1.0),
-		backendRetriesCounter:          statsdClient.NewCounter(statsdRetriesTotalName, 1.0),
-		backendOpenConnsGauge:          statsdClient.NewGauge(statsdOpenConnsName),
-		backendServerUpGauge:           statsdClient.NewGauge(statsdServerUpName),
+	registry := &standardRegistry{
+		configReloadsCounter:         statsdClient.NewCounter(statsdConfigReloadsName, 1.0),
+		configReloadsFailureCounter:  statsdClient.NewCounter(statsdConfigReloadsFailureName, 1.0),
+		lastConfigReloadSuccessGauge: statsdClient.NewGauge(statsdLastConfigReloadSuccessName),
+		lastConfigReloadFailureGauge: statsdClient.NewGauge(statsdLastConfigReloadFailureName),
 	}
+
+	if config.AddEntryPointsLabels {
+		registry.epEnabled = config.AddEntryPointsLabels
+		registry.entryPointReqsCounter = statsdClient.NewCounter(statsdEntryPointReqsName, 1.0)
+		registry.entryPointReqDurationHistogram = statsdClient.NewTiming(statsdEntryPointReqDurationName, 1.0)
+		registry.entryPointOpenConnsGauge = statsdClient.NewGauge(statsdEntryPointOpenConnsName)
+	}
+
+	if config.AddServicesLabels {
+		registry.svcEnabled = config.AddServicesLabels
+		registry.serviceReqsCounter = statsdClient.NewCounter(statsdMetricsServiceReqsName, 1.0)
+		registry.serviceReqDurationHistogram = statsdClient.NewTiming(statsdMetricsServiceLatencyName, 1.0)
+		registry.serviceRetriesCounter = statsdClient.NewCounter(statsdRetriesTotalName, 1.0)
+		registry.serviceOpenConnsGauge = statsdClient.NewGauge(statsdOpenConnsName)
+		registry.serviceServerUpGauge = statsdClient.NewGauge(statsdServerUpName)
+	}
+
+	return registry
 }
 
 // initStatsdTicker initializes metrics pusher and creates a statsdClient if not created already
@@ -66,7 +75,7 @@ func initStatsdTicker(ctx context.Context, config *types.Statsd) *time.Ticker {
 	report := time.NewTicker(time.Duration(config.PushInterval))
 
 	safe.Go(func() {
-		statsdClient.SendLoop(report.C, "udp", address)
+		statsdClient.SendLoop(ctx, report.C, "udp", address)
 	})
 
 	return report

pkg/metrics/statsd_test.go

@@ -15,37 +15,37 @@ func TestStatsD(t *testing.T) {
 	// This is needed to make sure that UDP Listener listens for data a bit longer, otherwise it will quit after a millisecond
 	udp.Timeout = 5 * time.Second
 
-	statsdRegistry := RegisterStatsd(context.Background(), &types.Statsd{Address: ":18125", PushInterval: types.Duration(time.Second)})
+	statsdRegistry := RegisterStatsd(context.Background(), &types.Statsd{Address: ":18125", PushInterval: types.Duration(time.Second), AddEntryPointsLabels: true, AddServicesLabels: true})
 	defer StopStatsd()
 
-	if !statsdRegistry.IsEnabled() {
+	if !statsdRegistry.IsEpEnabled() || !statsdRegistry.IsSvcEnabled() {
 		t.Errorf("Statsd registry should return true for IsEnabled()")
 	}
 
 	expected := []string{
 		// We are only validating counts, as it is nearly impossible to validate latency, since it varies every run
-		"traefik.backend.request.total:2.000000|c\n",
-		"traefik.backend.retries.total:2.000000|c\n",
-		"traefik.backend.request.duration:10000.000000|ms",
+		"traefik.service.request.total:2.000000|c\n",
+		"traefik.service.retries.total:2.000000|c\n",
+		"traefik.service.request.duration:10000.000000|ms",
 		"traefik.config.reload.total:1.000000|c\n",
 		"traefik.config.reload.total:1.000000|c\n",
 		"traefik.entrypoint.request.total:1.000000|c\n",
 		"traefik.entrypoint.request.duration:10000.000000|ms",
 		"traefik.entrypoint.connections.open:1.000000|g\n",
-		"traefik.backend.server.up:1.000000|g\n",
+		"traefik.service.server.up:1.000000|g\n",
 	}
 
 	udp.ShouldReceiveAll(t, expected, func() {
-		statsdRegistry.BackendReqsCounter().With("service", "test", "code", string(http.StatusOK), "method", http.MethodGet).Add(1)
-		statsdRegistry.BackendReqsCounter().With("service", "test", "code", string(http.StatusNotFound), "method", http.MethodGet).Add(1)
-		statsdRegistry.BackendRetriesCounter().With("service", "test").Add(1)
-		statsdRegistry.BackendRetriesCounter().With("service", "test").Add(1)
-		statsdRegistry.BackendReqDurationHistogram().With("service", "test", "code", string(http.StatusOK)).Observe(10000)
+		statsdRegistry.ServiceReqsCounter().With("service", "test", "code", string(http.StatusOK), "method", http.MethodGet).Add(1)
+		statsdRegistry.ServiceReqsCounter().With("service", "test", "code", string(http.StatusNotFound), "method", http.MethodGet).Add(1)
+		statsdRegistry.ServiceRetriesCounter().With("service", "test").Add(1)
+		statsdRegistry.ServiceRetriesCounter().With("service", "test").Add(1)
+		statsdRegistry.ServiceReqDurationHistogram().With("service", "test", "code", string(http.StatusOK)).Observe(10000)
 		statsdRegistry.ConfigReloadsCounter().Add(1)
 		statsdRegistry.ConfigReloadsFailureCounter().Add(1)
-		statsdRegistry.EntrypointReqsCounter().With("entrypoint", "test").Add(1)
-		statsdRegistry.EntrypointReqDurationHistogram().With("entrypoint", "test").Observe(10000)
-		statsdRegistry.EntrypointOpenConnsGauge().With("entrypoint", "test").Set(1)
-		statsdRegistry.BackendServerUpGauge().With("backend:test", "url", "http://127.0.0.1").Set(1)
+		statsdRegistry.EntryPointReqsCounter().With("entrypoint", "test").Add(1)
+		statsdRegistry.EntryPointReqDurationHistogram().With("entrypoint", "test").Observe(10000)
+		statsdRegistry.EntryPointOpenConnsGauge().With("entrypoint", "test").Set(1)
+		statsdRegistry.ServiceServerUpGauge().With("service:test", "url", "http://127.0.0.1").Set(1)
 	})
 }

pkg/middlewares/metrics/metrics.go

@@ -0,0 +1,158 @@
+package metrics
+
+import (
+	"context"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync/atomic"
+	"time"
+	"unicode/utf8"
+
+	"github.com/containous/alice"
+	"github.com/containous/traefik/pkg/log"
+	"github.com/containous/traefik/pkg/metrics"
+	"github.com/containous/traefik/pkg/middlewares"
+	"github.com/containous/traefik/pkg/middlewares/retry"
+	gokitmetrics "github.com/go-kit/kit/metrics"
+)
+
+const (
+	protoHTTP      = "http"
+	protoSSE       = "sse"
+	protoWebsocket = "websocket"
+	typeName       = "Metrics"
+	nameEntrypoint = "metrics-entrypoint"
+	nameService    = "metrics-service"
+)
+
+type metricsMiddleware struct {
+	// Important: Since this int64 field is using sync/atomic, it has to be at the top of the struct due to a bug on 32-bit platform
+	// See: https://golang.org/pkg/sync/atomic/ for more information
+	openConns            int64
+	next                 http.Handler
+	reqsCounter          gokitmetrics.Counter
+	reqDurationHistogram gokitmetrics.Histogram
+	openConnsGauge       gokitmetrics.Gauge
+	baseLabels           []string
+}
+
+// NewEntryPointMiddleware creates a new metrics middleware for an Entrypoint.
+func NewEntryPointMiddleware(ctx context.Context, next http.Handler, registry metrics.Registry, entryPointName string) http.Handler {
+	middlewares.GetLogger(ctx, nameEntrypoint, typeName).Debug("Creating middleware")
+
+	return &metricsMiddleware{
+		next:                 next,
+		reqsCounter:          registry.EntryPointReqsCounter(),
+		reqDurationHistogram: registry.EntryPointReqDurationHistogram(),
+		openConnsGauge:       registry.EntryPointOpenConnsGauge(),
+		baseLabels:           []string{"entrypoint", entryPointName},
+	}
+}
+
+// NewServiceMiddleware creates a new metrics middleware for a Service.
+func NewServiceMiddleware(ctx context.Context, next http.Handler, registry metrics.Registry, serviceName string) http.Handler {
+	middlewares.GetLogger(ctx, nameService, typeName).Debug("Creating middleware")
+
+	return &metricsMiddleware{
+		next:                 next,
+		reqsCounter:          registry.ServiceReqsCounter(),
+		reqDurationHistogram: registry.ServiceReqDurationHistogram(),
+		openConnsGauge:       registry.ServiceOpenConnsGauge(),
+		baseLabels:           []string{"service", serviceName},
+	}
+}
+
+// WrapEntryPointHandler Wraps metrics entrypoint to alice.Constructor.
+func WrapEntryPointHandler(ctx context.Context, registry metrics.Registry, entryPointName string) alice.Constructor {
+	return func(next http.Handler) (http.Handler, error) {
+		return NewEntryPointMiddleware(ctx, next, registry, entryPointName), nil
+	}
+}
+
+// WrapServiceHandler Wraps metrics service to alice.Constructor.
+func WrapServiceHandler(ctx context.Context, registry metrics.Registry, serviceName string) alice.Constructor {
+	return func(next http.Handler) (http.Handler, error) {
+		return NewServiceMiddleware(ctx, next, registry, serviceName), nil
+	}
+}
+
+func (m *metricsMiddleware) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	labels := []string{"method", getMethod(req), "protocol", getRequestProtocol(req)}
+	labels = append(labels, m.baseLabels...)
+
+	openConns := atomic.AddInt64(&m.openConns, 1)
+	m.openConnsGauge.With(labels...).Set(float64(openConns))
+	defer func(labelValues []string) {
+		openConns := atomic.AddInt64(&m.openConns, -1)
+		m.openConnsGauge.With(labelValues...).Set(float64(openConns))
+	}(labels)
+
+	start := time.Now()
+	recorder := &responseRecorder{rw, http.StatusOK}
+	m.next.ServeHTTP(recorder, req)
+
+	labels = append(labels, "code", strconv.Itoa(recorder.statusCode))
+	m.reqsCounter.With(labels...).Add(1)
+	m.reqDurationHistogram.With(labels...).Observe(time.Since(start).Seconds())
+}
+
+func getRequestProtocol(req *http.Request) string {
+	switch {
+	case isWebsocketRequest(req):
+		return protoWebsocket
+	case isSSERequest(req):
+		return protoSSE
+	default:
+		return protoHTTP
+	}
+}
+
+// isWebsocketRequest determines if the specified HTTP request is a websocket handshake request.
+func isWebsocketRequest(req *http.Request) bool {
+	return containsHeader(req, "Connection", "upgrade") && containsHeader(req, "Upgrade", "websocket")
+}
+
+// isSSERequest determines if the specified HTTP request is a request for an event subscription.
+func isSSERequest(req *http.Request) bool {
+	return containsHeader(req, "Accept", "text/event-stream")
+}
+
+func containsHeader(req *http.Request, name, value string) bool {
+	items := strings.Split(req.Header.Get(name), ",")
+	for _, item := range items {
+		if value == strings.ToLower(strings.TrimSpace(item)) {
+			return true
+		}
+	}
+	return false
+}
+
+func getMethod(r *http.Request) string {
+	if !utf8.ValidString(r.Method) {
+		log.Warnf("Invalid HTTP method encoding: %s", r.Method)
+		return "NON_UTF8_HTTP_METHOD"
+	}
+	return r.Method
+}
+
+type retryMetrics interface {
+	ServiceRetriesCounter() gokitmetrics.Counter
+}
+
+// NewRetryListener instantiates a MetricsRetryListener with the given retryMetrics.
+func NewRetryListener(retryMetrics retryMetrics, serviceName string) retry.Listener {
+	return &RetryListener{retryMetrics: retryMetrics, serviceName: serviceName}
+}
+
+// RetryListener is an implementation of the RetryListener interface to
+// record RequestMetrics about retry attempts.
+type RetryListener struct {
+	retryMetrics retryMetrics
+	serviceName  string
+}
+
+// Retried tracks the retry in the RequestMetrics implementation.
+func (m *RetryListener) Retried(req *http.Request, attempt int) {
+	m.retryMetrics.ServiceRetriesCounter().With("service", m.serviceName).Add(1)
+}

pkg/middlewares/metrics/metrics_test.go

@@ -0,0 +1,58 @@
+package metrics
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"reflect"
+	"testing"
+
+	"github.com/go-kit/kit/metrics"
+)
+
+// CollectingCounter is a metrics.Counter implementation that enables access to the CounterValue and LastLabelValues.
+type CollectingCounter struct {
+	CounterValue    float64
+	LastLabelValues []string
+}
+
+// With is there to satisfy the metrics.Counter interface.
+func (c *CollectingCounter) With(labelValues ...string) metrics.Counter {
+	c.LastLabelValues = labelValues
+	return c
+}
+
+// Add is there to satisfy the metrics.Counter interface.
+func (c *CollectingCounter) Add(delta float64) {
+	c.CounterValue += delta
+}
+
+func TestMetricsRetryListener(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	retryMetrics := newCollectingRetryMetrics()
+	retryListener := NewRetryListener(retryMetrics, "serviceName")
+	retryListener.Retried(req, 1)
+	retryListener.Retried(req, 2)
+
+	wantCounterValue := float64(2)
+	if retryMetrics.retriesCounter.CounterValue != wantCounterValue {
+		t.Errorf("got counter value of %f, want %f", retryMetrics.retriesCounter.CounterValue, wantCounterValue)
+	}
+
+	wantLabelValues := []string{"service", "serviceName"}
+	if !reflect.DeepEqual(retryMetrics.retriesCounter.LastLabelValues, wantLabelValues) {
+		t.Errorf("wrong label values %v used, want %v", retryMetrics.retriesCounter.LastLabelValues, wantLabelValues)
+	}
+}
+
+// collectingRetryMetrics is an implementation of the retryMetrics interface that can be used inside tests to collect the times Add() was called.
+type collectingRetryMetrics struct {
+	retriesCounter *CollectingCounter
+}
+
+func newCollectingRetryMetrics() *collectingRetryMetrics {
+	return &collectingRetryMetrics{retriesCounter: &CollectingCounter{}}
+}
+
+func (m *collectingRetryMetrics) ServiceRetriesCounter() metrics.Counter {
+	return m.retriesCounter
+}

pkg/middlewares/metrics/recorder.go

@@ -0,0 +1,37 @@
+package metrics
+
+import (
+	"bufio"
+	"net"
+	"net/http"
+)
+
+// responseRecorder captures information from the response and preserves it for
+// later analysis.
+type responseRecorder struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+// WriteHeader captures the status code for later retrieval.
+func (r *responseRecorder) WriteHeader(status int) {
+	r.ResponseWriter.WriteHeader(status)
+	r.statusCode = status
+}
+
+// Hijack hijacks the connection
+func (r *responseRecorder) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return r.ResponseWriter.(http.Hijacker).Hijack()
+}
+
+// CloseNotify returns a channel that receives at most a
+// single value (true) when the client connection has gone
+// away.
+func (r *responseRecorder) CloseNotify() <-chan bool {
+	return r.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+
+// Flush sends any buffered data to the client.
+func (r *responseRecorder) Flush() {
+	r.ResponseWriter.(http.Flusher).Flush()
+}

pkg/server/router/router_test.go

@@ -306,7 +306,7 @@ func TestRouterManager_Get(t *testing.T) {
 					Middlewares: test.middlewaresConfig,
 				},
 			})
-			serviceManager := service.NewManager(rtConf.Services, http.DefaultTransport)
+			serviceManager := service.NewManager(rtConf.Services, http.DefaultTransport, nil)
 			middlewaresBuilder := middleware.NewBuilder(rtConf.Middlewares, serviceManager)
 			responseModifierFactory := responsemodifiers.NewBuilder(rtConf.Middlewares)
 			routerManager := NewManager(rtConf, serviceManager, middlewaresBuilder, responseModifierFactory)
@@ -407,7 +407,7 @@ func TestAccessLog(t *testing.T) {
 					Middlewares: test.middlewaresConfig,
 				},
 			})
-			serviceManager := service.NewManager(rtConf.Services, http.DefaultTransport)
+			serviceManager := service.NewManager(rtConf.Services, http.DefaultTransport, nil)
 			middlewaresBuilder := middleware.NewBuilder(rtConf.Middlewares, serviceManager)
 			responseModifierFactory := responsemodifiers.NewBuilder(rtConf.Middlewares)
 			routerManager := NewManager(rtConf, serviceManager, middlewaresBuilder, responseModifierFactory)
@@ -693,7 +693,7 @@ func TestRuntimeConfiguration(t *testing.T) {
 					Middlewares: test.middlewareConfig,
 				},
 			})
-			serviceManager := service.NewManager(rtConf.Services, http.DefaultTransport)
+			serviceManager := service.NewManager(rtConf.Services, http.DefaultTransport, nil)
 			middlewaresBuilder := middleware.NewBuilder(rtConf.Middlewares, serviceManager)
 			responseModifierFactory := responsemodifiers.NewBuilder(map[string]*runtime.MiddlewareInfo{})
 			routerManager := NewManager(rtConf, serviceManager, middlewaresBuilder, responseModifierFactory)
@@ -767,7 +767,7 @@ func BenchmarkRouterServe(b *testing.B) {
 			Middlewares: map[string]*dynamic.Middleware{},
 		},
 	})
-	serviceManager := service.NewManager(rtConf.Services, &staticTransport{res})
+	serviceManager := service.NewManager(rtConf.Services, &staticTransport{res}, nil)
 	middlewaresBuilder := middleware.NewBuilder(rtConf.Middlewares, serviceManager)
 	responseModifierFactory := responsemodifiers.NewBuilder(rtConf.Middlewares)
 	routerManager := NewManager(rtConf, serviceManager, middlewaresBuilder, responseModifierFactory)
@@ -808,7 +808,7 @@ func BenchmarkService(b *testing.B) {
 			Services: serviceConfig,
 		},
 	})
-	serviceManager := service.NewManager(rtConf.Services, &staticTransport{res})
+	serviceManager := service.NewManager(rtConf.Services, &staticTransport{res}, nil)
 	w := httptest.NewRecorder()
 	req := testhelpers.MustNewRequest(http.MethodGet, "http://foo.bar/", nil)
 

pkg/server/server_configuration.go

@@ -12,7 +12,9 @@ import (
 	"github.com/containous/traefik/pkg/config/dynamic"
 	"github.com/containous/traefik/pkg/config/runtime"
 	"github.com/containous/traefik/pkg/log"
+	"github.com/containous/traefik/pkg/metrics"
 	"github.com/containous/traefik/pkg/middlewares/accesslog"
+	metricsmiddleware "github.com/containous/traefik/pkg/middlewares/metrics"
 	"github.com/containous/traefik/pkg/middlewares/requestdecorator"
 	"github.com/containous/traefik/pkg/middlewares/tracing"
 	"github.com/containous/traefik/pkg/responsemodifiers"
@@ -49,7 +51,13 @@ func (s *Server) loadConfiguration(configMsg dynamic.Message) {
 		listener(*configMsg.Configuration)
 	}
 
-	s.postLoadConfiguration()
+	if s.metricsRegistry.IsEpEnabled() || s.metricsRegistry.IsSvcEnabled() {
+		var entrypoints []string
+		for key := range s.entryPointsTCP {
+			entrypoints = append(entrypoints, key)
+		}
+		metrics.OnConfigurationUpdate(newConfigurations, entrypoints)
+	}
 }
 
 // loadConfigurationTCP returns a new gorilla.mux Route from the specified global configuration and the dynamic
@@ -89,7 +97,7 @@ func (s *Server) createTCPRouters(ctx context.Context, configuration *runtime.Co
 
 // createHTTPHandlers returns, for the given configuration and entryPoints, the HTTP handlers for non-TLS connections, and for the TLS ones. the given configuration must not be nil. its fields will get mutated.
 func (s *Server) createHTTPHandlers(ctx context.Context, configuration *runtime.Configuration, entryPoints []string) (map[string]http.Handler, map[string]http.Handler) {
-	serviceManager := service.NewManager(configuration.Services, s.defaultRoundTripper)
+	serviceManager := service.NewManager(configuration.Services, s.defaultRoundTripper, s.metricsRegistry)
 	middlewaresBuilder := middleware.NewBuilder(configuration.Middlewares, serviceManager)
 	responseModifierFactory := responsemodifiers.NewBuilder(configuration.Middlewares)
 	routerManager := router.NewManager(configuration, serviceManager, middlewaresBuilder, responseModifierFactory)
@@ -128,6 +136,10 @@ func (s *Server) createHTTPHandlers(ctx context.Context, configuration *runtime.
 			chain = chain.Append(tracing.WrapEntryPointHandler(ctx, s.tracer, entryPointName))
 		}
 
+		if s.metricsRegistry.IsEpEnabled() {
+			chain = chain.Append(metricsmiddleware.WrapEntryPointHandler(ctx, s.metricsRegistry, entryPointName))
+		}
+
 		chain = chain.Append(requestdecorator.WrapHandler(s.requestDecorator))
 
 		handler, err := chain.Then(internalMuxRouter.NotFoundHandler)
@@ -266,15 +278,6 @@ func (s *Server) throttleProviderConfigReload(throttle time.Duration, publish ch
 	}
 }
 
-func (s *Server) postLoadConfiguration() {
-	// FIXME metrics
-	// if s.metricsRegistry.IsEnabled() {
-	// 	activeConfig := s.currentConfigurations.Get().(config.Configurations)
-	// 	metrics.OnConfigurationUpdate(activeConfig)
-	// }
-
-}
-
 func buildDefaultHTTPRouter() *mux.Router {
 	rt := mux.NewRouter()
 	rt.NotFoundHandler = http.HandlerFunc(http.NotFound)

pkg/server/service/service.go

@@ -13,8 +13,10 @@ import (
 	"github.com/containous/traefik/pkg/config/runtime"
 	"github.com/containous/traefik/pkg/healthcheck"
 	"github.com/containous/traefik/pkg/log"
+	"github.com/containous/traefik/pkg/metrics"
 	"github.com/containous/traefik/pkg/middlewares/accesslog"
 	"github.com/containous/traefik/pkg/middlewares/emptybackendhandler"
+	metricsMiddle "github.com/containous/traefik/pkg/middlewares/metrics"
 	"github.com/containous/traefik/pkg/middlewares/pipelining"
 	"github.com/containous/traefik/pkg/server/cookie"
 	"github.com/containous/traefik/pkg/server/internal"
@@ -27,8 +29,9 @@ const (
 )
 
 // NewManager creates a new Manager
-func NewManager(configs map[string]*runtime.ServiceInfo, defaultRoundTripper http.RoundTripper) *Manager {
+func NewManager(configs map[string]*runtime.ServiceInfo, defaultRoundTripper http.RoundTripper, metricsRegistry metrics.Registry) *Manager {
 	return &Manager{
+		metricsRegistry:     metricsRegistry,
 		bufferPool:          newBufferPool(),
 		defaultRoundTripper: defaultRoundTripper,
 		balancers:           make(map[string][]healthcheck.BalancerHandler),
@@ -38,6 +41,7 @@ func NewManager(configs map[string]*runtime.ServiceInfo, defaultRoundTripper htt
 
 // Manager The service manager
 type Manager struct {
+	metricsRegistry     metrics.Registry
 	bufferPool          httputil.BufferPool
 	defaultRoundTripper http.RoundTripper
 	balancers           map[string][]healthcheck.BalancerHandler
@@ -87,8 +91,12 @@ func (m *Manager) getLoadBalancerServiceHandler(
 	alHandler := func(next http.Handler) (http.Handler, error) {
 		return accesslog.NewFieldHandler(next, accesslog.ServiceName, serviceName, accesslog.AddServiceFields), nil
 	}
+	chain := alice.New()
+	if m.metricsRegistry != nil && m.metricsRegistry.IsSvcEnabled() {
+		chain = chain.Append(metricsMiddle.WrapServiceHandler(ctx, m.metricsRegistry, serviceName))
+	}
 
-	handler, err := alice.New().Append(alHandler).Then(pipelining.New(ctx, fwd, "pipelining"))
+	handler, err := chain.Append(alHandler).Then(pipelining.New(ctx, fwd, "pipelining"))
 	if err != nil {
 		return nil, err
 	}

pkg/server/service/service_test.go

@@ -80,7 +80,7 @@ func TestGetLoadBalancer(t *testing.T) {
 }
 
 func TestGetLoadBalancerServiceHandler(t *testing.T) {
-	sm := NewManager(nil, http.DefaultTransport)
+	sm := NewManager(nil, http.DefaultTransport, nil)
 
 	server1 := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("X-From", "first")
@@ -332,7 +332,7 @@ func TestManager_Build(t *testing.T) {
 		t.Run(test.desc, func(t *testing.T) {
 			t.Parallel()
 
-			manager := NewManager(test.configs, http.DefaultTransport)
+			manager := NewManager(test.configs, http.DefaultTransport, nil)
 
 			ctx := context.Background()
 			if len(test.providerName) > 0 {

pkg/types/metrics.go

@@ -4,7 +4,7 @@ import (
 	"time"
 )
 
-// Metrics provides options to expose and send Traefik metrics to different third party monitoring systems
+// Metrics provides options to expose and send Traefik metrics to different third party monitoring systems.
 type Metrics struct {
 	Prometheus *Prometheus `description:"Prometheus metrics exporter type." json:"prometheus,omitempty" toml:"prometheus,omitempty" yaml:"prometheus,omitempty" export:"true" label:"allowEmpty"`
 	DataDog    *DataDog    `description:"DataDog metrics exporter type." json:"dataDog,omitempty" toml:"dataDog,omitempty" yaml:"dataDog,omitempty" export:"true" label:"allowEmpty"`
@@ -12,52 +12,66 @@ type Metrics struct {
 	InfluxDB   *InfluxDB   `description:"InfluxDB metrics exporter type." json:"influxDB,omitempty" toml:"influxDB,omitempty" yaml:"influxDB,omitempty" label:"allowEmpty"`
 }
 
-// Prometheus can contain specific configuration used by the Prometheus Metrics exporter
+// Prometheus can contain specific configuration used by the Prometheus Metrics exporter.
 type Prometheus struct {
-	Buckets     []float64 `description:"Buckets for latency metrics." json:"buckets,omitempty" toml:"buckets,omitempty" yaml:"buckets,omitempty" export:"true"`
-	EntryPoint  string    `description:"EntryPoint." json:"entryPoint,omitempty" toml:"entryPoint,omitempty" yaml:"entryPoint,omitempty" export:"true"`
-	Middlewares []string  `description:"Middlewares." json:"middlewares,omitempty" toml:"middlewares,omitempty" yaml:"middlewares,omitempty" export:"true"`
+	Buckets              []float64 `description:"Buckets for latency metrics." json:"buckets,omitempty" toml:"buckets,omitempty" yaml:"buckets,omitempty" export:"true"`
+	EntryPoint           string    `description:"EntryPoint." json:"entryPoint,omitempty" toml:"entryPoint,omitempty" yaml:"entryPoint,omitempty" export:"true"`
+	Middlewares          []string  `description:"Middlewares." json:"middlewares,omitempty" toml:"middlewares,omitempty" yaml:"middlewares,omitempty" export:"true"`
+	AddEntryPointsLabels bool      `description:"Enable metrics on entry points." json:"addEntryPointsLabels,omitempty" toml:"addEntryPointsLabels,omitempty" yaml:"addEntryPointsLabels,omitempty" export:"true"`
+	AddServicesLabels    bool      `description:"Enable metrics on services." json:"addServicesLabels,omitempty" toml:"addServicesLabels,omitempty" yaml:"addServicesLabels,omitempty" export:"true"`
 }
 
 // SetDefaults sets the default values.
 func (p *Prometheus) SetDefaults() {
 	p.Buckets = []float64{0.1, 0.3, 1.2, 5}
 	p.EntryPoint = "traefik"
+	p.AddEntryPointsLabels = true
+	p.AddServicesLabels = true
 }
 
-// DataDog contains address and metrics pushing interval configuration
+// DataDog contains address and metrics pushing interval configuration.
 type DataDog struct {
-	Address      string   `description:"DataDog's address." json:"address,omitempty" toml:"address,omitempty" yaml:"address,omitempty"`
-	PushInterval Duration `description:"DataDog push interval." json:"pushInterval,omitempty" toml:"pushInterval,omitempty" yaml:"pushInterval,omitempty" export:"true"`
+	Address              string   `description:"DataDog's address." json:"address,omitempty" toml:"address,omitempty" yaml:"address,omitempty"`
+	PushInterval         Duration `description:"DataDog push interval." json:"pushInterval,omitempty" toml:"pushInterval,omitempty" yaml:"pushInterval,omitempty" export:"true"`
+	AddEntryPointsLabels bool     `description:"Enable metrics on entry points." json:"addEntryPointsLabels,omitempty" toml:"addEntryPointsLabels,omitempty" yaml:"addEntryPointsLabels,omitempty" export:"true"`
+	AddServicesLabels    bool     `description:"Enable metrics on services." json:"addServicesLabels,omitempty" toml:"addServicesLabels,omitempty" yaml:"addServicesLabels,omitempty" export:"true"`
 }
 
 // SetDefaults sets the default values.
 func (d *DataDog) SetDefaults() {
 	d.Address = "localhost:8125"
 	d.PushInterval = Duration(10 * time.Second)
+	d.AddEntryPointsLabels = true
+	d.AddServicesLabels = true
 }
 
-// Statsd contains address and metrics pushing interval configuration
+// Statsd contains address and metrics pushing interval configuration.
 type Statsd struct {
-	Address      string   `description:"StatsD address." json:"address,omitempty" toml:"address,omitempty" yaml:"address,omitempty"`
-	PushInterval Duration `description:"StatsD push interval." json:"pushInterval,omitempty" toml:"pushInterval,omitempty" yaml:"pushInterval,omitempty" export:"true"`
+	Address              string   `description:"StatsD address." json:"address,omitempty" toml:"address,omitempty" yaml:"address,omitempty"`
+	PushInterval         Duration `description:"StatsD push interval." json:"pushInterval,omitempty" toml:"pushInterval,omitempty" yaml:"pushInterval,omitempty" export:"true"`
+	AddEntryPointsLabels bool     `description:"Enable metrics on entry points." json:"addEntryPointsLabels,omitempty" toml:"addEntryPointsLabels,omitempty" yaml:"addEntryPointsLabels,omitempty" export:"true"`
+	AddServicesLabels    bool     `description:"Enable metrics on services." json:"addServicesLabels,omitempty" toml:"addServicesLabels,omitempty" yaml:"addServicesLabels,omitempty" export:"true"`
 }
 
 // SetDefaults sets the default values.
 func (s *Statsd) SetDefaults() {
 	s.Address = "localhost:8125"
 	s.PushInterval = Duration(10 * time.Second)
+	s.AddEntryPointsLabels = true
+	s.AddServicesLabels = true
 }
 
-// InfluxDB contains address, login and metrics pushing interval configuration
+// InfluxDB contains address, login and metrics pushing interval configuration.
 type InfluxDB struct {
-	Address         string   `description:"InfluxDB address." json:"address,omitempty" toml:"address,omitempty" yaml:"address,omitempty"`
-	Protocol        string   `description:"InfluxDB address protocol (udp or http)." json:"protocol,omitempty" toml:"protocol,omitempty" yaml:"protocol,omitempty"`
-	PushInterval    Duration `description:"InfluxDB push interval." json:"pushInterval,omitempty" toml:"pushInterval,omitempty" yaml:"pushInterval,omitempty" export:"true"`
-	Database        string   `description:"InfluxDB database used when protocol is http." json:"database,omitempty" toml:"database,omitempty" yaml:"database,omitempty" export:"true"`
-	RetentionPolicy string   `description:"InfluxDB retention policy used when protocol is http." json:"retentionPolicy,omitempty" toml:"retentionPolicy,omitempty" yaml:"retentionPolicy,omitempty" export:"true"`
-	Username        string   `description:"InfluxDB username (only with http)." json:"username,omitempty" toml:"username,omitempty" yaml:"username,omitempty" export:"true"`
-	Password        string   `description:"InfluxDB password (only with http)." json:"password,omitempty" toml:"password,omitempty" yaml:"password,omitempty" export:"true"`
+	Address              string   `description:"InfluxDB address." json:"address,omitempty" toml:"address,omitempty" yaml:"address,omitempty"`
+	Protocol             string   `description:"InfluxDB address protocol (udp or http)." json:"protocol,omitempty" toml:"protocol,omitempty" yaml:"protocol,omitempty"`
+	PushInterval         Duration `description:"InfluxDB push interval." json:"pushInterval,omitempty" toml:"pushInterval,omitempty" yaml:"pushInterval,omitempty" export:"true"`
+	Database             string   `description:"InfluxDB database used when protocol is http." json:"database,omitempty" toml:"database,omitempty" yaml:"database,omitempty" export:"true"`
+	RetentionPolicy      string   `description:"InfluxDB retention policy used when protocol is http." json:"retentionPolicy,omitempty" toml:"retentionPolicy,omitempty" yaml:"retentionPolicy,omitempty" export:"true"`
+	Username             string   `description:"InfluxDB username (only with http)." json:"username,omitempty" toml:"username,omitempty" yaml:"username,omitempty" export:"true"`
+	Password             string   `description:"InfluxDB password (only with http)." json:"password,omitempty" toml:"password,omitempty" yaml:"password,omitempty" export:"true"`
+	AddEntryPointsLabels bool     `description:"Enable metrics on entry points." json:"addEntryPointsLabels,omitempty" toml:"addEntryPointsLabels,omitempty" yaml:"addEntryPointsLabels,omitempty" export:"true"`
+	AddServicesLabels    bool     `description:"Enable metrics on services." json:"addServicesLabels,omitempty" toml:"addServicesLabels,omitempty" yaml:"addServicesLabels,omitempty" export:"true"`
 }
 
 // SetDefaults sets the default values.
@@ -65,9 +79,11 @@ func (i *InfluxDB) SetDefaults() {
 	i.Address = "localhost:8089"
 	i.Protocol = "udp"
 	i.PushInterval = Duration(10 * time.Second)
+	i.AddEntryPointsLabels = true
+	i.AddServicesLabels = true
 }
 
-// Statistics provides options for monitoring request and response stats
+// Statistics provides options for monitoring request and response stats.
 type Statistics struct {
 	RecentErrors int `description:"Number of recent errors logged." json:"recentErrors,omitempty" toml:"recentErrors,omitempty" yaml:"recentErrors,omitempty" export:"true"`
 }

vendor/github.com/go-kit/kit/log/value.go

@@ -1,9 +1,10 @@
 package log
 
 import (
+	"runtime"
+	"strconv"
+	"strings"
 	"time"
-
-	"github.com/go-stack/stack"
 )
 
 // A Valuer generates a log value. When passed to With or WithPrefix in a
@@ -81,7 +82,14 @@ func (tf timeFormat) MarshalText() (text []byte, err error) {
 // Caller returns a Valuer that returns a file and line from a specified depth
 // in the callstack. Users will probably want to use DefaultCaller.
 func Caller(depth int) Valuer {
-	return func() interface{} { return stack.Caller(depth) }
+	return func() interface{} {
+		_, file, line, _ := runtime.Caller(depth)
+		idx := strings.LastIndexByte(file, '/')
+		// using idx+1 below handles both of following cases:
+		// idx == -1 because no "/" was found, or
+		// idx >= 0 and we want to start at the character after the found "/".
+		return file[idx+1:] + ":" + strconv.Itoa(line)
+	}
 }
 
 var (

vendor/github.com/go-kit/kit/metrics/dogstatsd/dogstatsd.go

@@ -11,8 +11,10 @@
 package dogstatsd
 
 import (
+	"context"
 	"fmt"
 	"io"
+	"math/rand"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -72,7 +74,7 @@ func (d *Dogstatsd) NewCounter(name string, sampleRate float64) *Counter {
 	d.rates.Set(name, sampleRate)
 	return &Counter{
 		name: name,
-		obs:  d.counters.Observe,
+		obs:  sampleObservations(d.counters.Observe, sampleRate),
 	}
 }
 
@@ -94,7 +96,7 @@ func (d *Dogstatsd) NewTiming(name string, sampleRate float64) *Timing {
 	d.rates.Set(name, sampleRate)
 	return &Timing{
 		name: name,
-		obs:  d.timings.Observe,
+		obs:  sampleObservations(d.timings.Observe, sampleRate),
 	}
 }
 
@@ -104,29 +106,34 @@ func (d *Dogstatsd) NewHistogram(name string, sampleRate float64) *Histogram {
 	d.rates.Set(name, sampleRate)
 	return &Histogram{
 		name: name,
-		obs:  d.histograms.Observe,
+		obs:  sampleObservations(d.histograms.Observe, sampleRate),
 	}
 }
 
 // WriteLoop is a helper method that invokes WriteTo to the passed writer every
-// time the passed channel fires. This method blocks until the channel is
-// closed, so clients probably want to run it in its own goroutine. For typical
+// time the passed channel fires. This method blocks until ctx is canceled,
+// so clients probably want to run it in its own goroutine. For typical
 // usage, create a time.Ticker and pass its C channel to this method.
-func (d *Dogstatsd) WriteLoop(c <-chan time.Time, w io.Writer) {
-	for range c {
-		if _, err := d.WriteTo(w); err != nil {
-			d.logger.Log("during", "WriteTo", "err", err)
+func (d *Dogstatsd) WriteLoop(ctx context.Context, c <-chan time.Time, w io.Writer) {
+	for {
+		select {
+		case <-c:
+			if _, err := d.WriteTo(w); err != nil {
+				d.logger.Log("during", "WriteTo", "err", err)
+			}
+		case <-ctx.Done():
+			return
 		}
 	}
 }
 
 // SendLoop is a helper method that wraps WriteLoop, passing a managed
 // connection to the network and address. Like WriteLoop, this method blocks
-// until the channel is closed, so clients probably want to start it in its own
+// until ctx is canceled, so clients probably want to start it in its own
 // goroutine. For typical usage, create a time.Ticker and pass its C channel to
 // this method.
-func (d *Dogstatsd) SendLoop(c <-chan time.Time, network, address string) {
-	d.WriteLoop(c, conn.NewDefaultManager(network, address, d.logger))
+func (d *Dogstatsd) SendLoop(ctx context.Context, c <-chan time.Time, network, address string) {
+	d.WriteLoop(ctx, c, conn.NewDefaultManager(network, address, d.logger))
 }
 
 // WriteTo flushes the buffered content of the metrics to the writer, in
@@ -233,6 +240,19 @@ func (d *Dogstatsd) tagValues(labelValues []string) string {
 
 type observeFunc func(name string, lvs lv.LabelValues, value float64)
 
+// sampleObservations returns a modified observeFunc that samples observations.
+func sampleObservations(obs observeFunc, sampleRate float64) observeFunc {
+	if sampleRate >= 1 {
+		return obs
+	}
+	return func(name string, lvs lv.LabelValues, value float64) {
+		if rand.Float64() > sampleRate {
+			return
+		}
+		obs(name, lvs, value)
+	}
+}
+
 // Counter is a DogStatsD counter. Observations are forwarded to a Dogstatsd
 // object, and aggregated (summed) per timeseries.
 type Counter struct {

vendor/github.com/go-kit/kit/metrics/influx/influx.go

@@ -4,9 +4,10 @@
 package influx
 
 import (
+	"context"
 	"time"
 
-	influxdb "github.com/influxdata/influxdb/client/v2"
+	influxdb "github.com/influxdata/influxdb1-client/v2"
 
 	"github.com/go-kit/kit/log"
 	"github.com/go-kit/kit/metrics"
@@ -88,10 +89,15 @@ type BatchPointsWriter interface {
 // time the passed channel fires. This method blocks until the channel is
 // closed, so clients probably want to run it in its own goroutine. For typical
 // usage, create a time.Ticker and pass its C channel to this method.
-func (in *Influx) WriteLoop(c <-chan time.Time, w BatchPointsWriter) {
-	for range c {
-		if err := in.WriteTo(w); err != nil {
-			in.logger.Log("during", "WriteTo", "err", err)
+func (in *Influx) WriteLoop(ctx context.Context, c <-chan time.Time, w BatchPointsWriter) {
+	for {
+		select {
+		case <-c:
+			if err := in.WriteTo(w); err != nil {
+				in.logger.Log("during", "WriteTo", "err", err)
+			}
+		case <-ctx.Done():
+			return
 		}
 	}
 }

vendor/github.com/go-kit/kit/metrics/internal/lv/space.go

@@ -79,7 +79,7 @@ type pair struct{ label, value string }
 func (n *node) observe(lvs LabelValues, value float64) {
 	n.mtx.Lock()
 	defer n.mtx.Unlock()
-	if len(lvs) == 0 {
+	if len(lvs) <= 0 {
 		n.observations = append(n.observations, value)
 		return
 	}
@@ -101,7 +101,7 @@ func (n *node) observe(lvs LabelValues, value float64) {
 func (n *node) add(lvs LabelValues, delta float64) {
 	n.mtx.Lock()
 	defer n.mtx.Unlock()
-	if len(lvs) == 0 {
+	if len(lvs) <= 0 {
 		var value float64
 		if len(n.observations) > 0 {
 			value = last(n.observations) + delta

vendor/github.com/go-kit/kit/metrics/statsd/statsd.go

@@ -9,6 +9,7 @@
 package statsd
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"time"
@@ -89,24 +90,29 @@ func (s *Statsd) NewTiming(name string, sampleRate float64) *Timing {
 }
 
 // WriteLoop is a helper method that invokes WriteTo to the passed writer every
-// time the passed channel fires. This method blocks until the channel is
-// closed, so clients probably want to run it in its own goroutine. For typical
+// time the passed channel fires. This method blocks until ctx is canceled,
+// so clients probably want to run it in its own goroutine. For typical
 // usage, create a time.Ticker and pass its C channel to this method.
-func (s *Statsd) WriteLoop(c <-chan time.Time, w io.Writer) {
-	for range c {
-		if _, err := s.WriteTo(w); err != nil {
-			s.logger.Log("during", "WriteTo", "err", err)
+func (s *Statsd) WriteLoop(ctx context.Context, c <-chan time.Time, w io.Writer) {
+	for {
+		select {
+		case <-c:
+			if _, err := s.WriteTo(w); err != nil {
+				s.logger.Log("during", "WriteTo", "err", err)
+			}
+		case <-ctx.Done():
+			return
 		}
 	}
 }
 
 // SendLoop is a helper method that wraps WriteLoop, passing a managed
 // connection to the network and address. Like WriteLoop, this method blocks
-// until the channel is closed, so clients probably want to start it in its own
+// until ctx is canceled, so clients probably want to start it in its own
 // goroutine. For typical usage, create a time.Ticker and pass its C channel to
 // this method.
-func (s *Statsd) SendLoop(c <-chan time.Time, network, address string) {
-	s.WriteLoop(c, conn.NewDefaultManager(network, address, s.logger))
+func (s *Statsd) SendLoop(ctx context.Context, c <-chan time.Time, network, address string) {
+	s.WriteLoop(ctx, c, conn.NewDefaultManager(network, address, s.logger))
 }
 
 // WriteTo flushes the buffered content of the metrics to the writer, in

vendor/github.com/go-kit/kit/util/conn/manager.go

@@ -2,6 +2,7 @@ package conn
 
 import (
 	"errors"
+	"math/rand"
 	"net"
 	"time"
 
@@ -103,7 +104,7 @@ func (m *Manager) loop() {
 		case conn = <-connc:
 			if conn == nil {
 				// didn't work
-				backoff = exponential(backoff) // wait longer
+				backoff = Exponential(backoff) // wait longer
 				reconnectc = m.after(backoff)  // try again
 			} else {
 				// worked!
@@ -132,12 +133,18 @@ func dial(d Dialer, network, address string, logger log.Logger) net.Conn {
 	return conn
 }
 
-func exponential(d time.Duration) time.Duration {
+// Exponential takes a duration and returns another one that is twice as long, +/- 50%. It is
+// used to provide backoff for operations that may fail and should avoid thundering herds.
+// See https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/ for rationale
+func Exponential(d time.Duration) time.Duration {
 	d *= 2
+	jitter := rand.Float64() + 0.5
+	d = time.Duration(int64(float64(d.Nanoseconds()) * jitter))
 	if d > time.Minute {
 		d = time.Minute
 	}
 	return d
+
 }
 
 // ErrConnectionUnavailable is returned by the Manager's Write method when the

vendor/github.com/go-stack/stack/stack.go

@@ -1,322 +0,0 @@
-// Package stack implements utilities to capture, manipulate, and format call
-// stacks. It provides a simpler API than package runtime.
-//
-// The implementation takes care of the minutia and special cases of
-// interpreting the program counter (pc) values returned by runtime.Callers.
-//
-// Package stack's types implement fmt.Formatter, which provides a simple and
-// flexible way to declaratively configure formatting when used with logging
-// or error tracking packages.
-package stack
-
-import (
-	"bytes"
-	"errors"
-	"fmt"
-	"io"
-	"runtime"
-	"strconv"
-	"strings"
-)
-
-// Call records a single function invocation from a goroutine stack.
-type Call struct {
-	fn *runtime.Func
-	pc uintptr
-}
-
-// Caller returns a Call from the stack of the current goroutine. The argument
-// skip is the number of stack frames to ascend, with 0 identifying the
-// calling function.
-func Caller(skip int) Call {
-	var pcs [2]uintptr
-	n := runtime.Callers(skip+1, pcs[:])
-
-	var c Call
-
-	if n < 2 {
-		return c
-	}
-
-	c.pc = pcs[1]
-	if runtime.FuncForPC(pcs[0]).Name() != "runtime.sigpanic" {
-		c.pc--
-	}
-	c.fn = runtime.FuncForPC(c.pc)
-	return c
-}
-
-// String implements fmt.Stinger. It is equivalent to fmt.Sprintf("%v", c).
-func (c Call) String() string {
-	return fmt.Sprint(c)
-}
-
-// MarshalText implements encoding.TextMarshaler. It formats the Call the same
-// as fmt.Sprintf("%v", c).
-func (c Call) MarshalText() ([]byte, error) {
-	if c.fn == nil {
-		return nil, ErrNoFunc
-	}
-	buf := bytes.Buffer{}
-	fmt.Fprint(&buf, c)
-	return buf.Bytes(), nil
-}
-
-// ErrNoFunc means that the Call has a nil *runtime.Func. The most likely
-// cause is a Call with the zero value.
-var ErrNoFunc = errors.New("no call stack information")
-
-// Format implements fmt.Formatter with support for the following verbs.
-//
-//    %s    source file
-//    %d    line number
-//    %n    function name
-//    %v    equivalent to %s:%d
-//
-// It accepts the '+' and '#' flags for most of the verbs as follows.
-//
-//    %+s   path of source file relative to the compile time GOPATH
-//    %#s   full path of source file
-//    %+n   import path qualified function name
-//    %+v   equivalent to %+s:%d
-//    %#v   equivalent to %#s:%d
-func (c Call) Format(s fmt.State, verb rune) {
-	if c.fn == nil {
-		fmt.Fprintf(s, "%%!%c(NOFUNC)", verb)
-		return
-	}
-
-	switch verb {
-	case 's', 'v':
-		file, line := c.fn.FileLine(c.pc)
-		switch {
-		case s.Flag('#'):
-			// done
-		case s.Flag('+'):
-			file = file[pkgIndex(file, c.fn.Name()):]
-		default:
-			const sep = "/"
-			if i := strings.LastIndex(file, sep); i != -1 {
-				file = file[i+len(sep):]
-			}
-		}
-		io.WriteString(s, file)
-		if verb == 'v' {
-			buf := [7]byte{':'}
-			s.Write(strconv.AppendInt(buf[:1], int64(line), 10))
-		}
-
-	case 'd':
-		_, line := c.fn.FileLine(c.pc)
-		buf := [6]byte{}
-		s.Write(strconv.AppendInt(buf[:0], int64(line), 10))
-
-	case 'n':
-		name := c.fn.Name()
-		if !s.Flag('+') {
-			const pathSep = "/"
-			if i := strings.LastIndex(name, pathSep); i != -1 {
-				name = name[i+len(pathSep):]
-			}
-			const pkgSep = "."
-			if i := strings.Index(name, pkgSep); i != -1 {
-				name = name[i+len(pkgSep):]
-			}
-		}
-		io.WriteString(s, name)
-	}
-}
-
-// PC returns the program counter for this call frame; multiple frames may
-// have the same PC value.
-func (c Call) PC() uintptr {
-	return c.pc
-}
-
-// name returns the import path qualified name of the function containing the
-// call.
-func (c Call) name() string {
-	if c.fn == nil {
-		return "???"
-	}
-	return c.fn.Name()
-}
-
-func (c Call) file() string {
-	if c.fn == nil {
-		return "???"
-	}
-	file, _ := c.fn.FileLine(c.pc)
-	return file
-}
-
-func (c Call) line() int {
-	if c.fn == nil {
-		return 0
-	}
-	_, line := c.fn.FileLine(c.pc)
-	return line
-}
-
-// CallStack records a sequence of function invocations from a goroutine
-// stack.
-type CallStack []Call
-
-// String implements fmt.Stinger. It is equivalent to fmt.Sprintf("%v", cs).
-func (cs CallStack) String() string {
-	return fmt.Sprint(cs)
-}
-
-var (
-	openBracketBytes  = []byte("[")
-	closeBracketBytes = []byte("]")
-	spaceBytes        = []byte(" ")
-)
-
-// MarshalText implements encoding.TextMarshaler. It formats the CallStack the
-// same as fmt.Sprintf("%v", cs).
-func (cs CallStack) MarshalText() ([]byte, error) {
-	buf := bytes.Buffer{}
-	buf.Write(openBracketBytes)
-	for i, pc := range cs {
-		if pc.fn == nil {
-			return nil, ErrNoFunc
-		}
-		if i > 0 {
-			buf.Write(spaceBytes)
-		}
-		fmt.Fprint(&buf, pc)
-	}
-	buf.Write(closeBracketBytes)
-	return buf.Bytes(), nil
-}
-
-// Format implements fmt.Formatter by printing the CallStack as square brackets
-// ([, ]) surrounding a space separated list of Calls each formatted with the
-// supplied verb and options.
-func (cs CallStack) Format(s fmt.State, verb rune) {
-	s.Write(openBracketBytes)
-	for i, pc := range cs {
-		if i > 0 {
-			s.Write(spaceBytes)
-		}
-		pc.Format(s, verb)
-	}
-	s.Write(closeBracketBytes)
-}
-
-// Trace returns a CallStack for the current goroutine with element 0
-// identifying the calling function.
-func Trace() CallStack {
-	var pcs [512]uintptr
-	n := runtime.Callers(2, pcs[:])
-	cs := make([]Call, n)
-
-	for i, pc := range pcs[:n] {
-		pcFix := pc
-		if i > 0 && cs[i-1].fn.Name() != "runtime.sigpanic" {
-			pcFix--
-		}
-		cs[i] = Call{
-			fn: runtime.FuncForPC(pcFix),
-			pc: pcFix,
-		}
-	}
-
-	return cs
-}
-
-// TrimBelow returns a slice of the CallStack with all entries below c
-// removed.
-func (cs CallStack) TrimBelow(c Call) CallStack {
-	for len(cs) > 0 && cs[0].pc != c.pc {
-		cs = cs[1:]
-	}
-	return cs
-}
-
-// TrimAbove returns a slice of the CallStack with all entries above c
-// removed.
-func (cs CallStack) TrimAbove(c Call) CallStack {
-	for len(cs) > 0 && cs[len(cs)-1].pc != c.pc {
-		cs = cs[:len(cs)-1]
-	}
-	return cs
-}
-
-// pkgIndex returns the index that results in file[index:] being the path of
-// file relative to the compile time GOPATH, and file[:index] being the
-// $GOPATH/src/ portion of file. funcName must be the name of a function in
-// file as returned by runtime.Func.Name.
-func pkgIndex(file, funcName string) int {
-	// As of Go 1.6.2 there is no direct way to know the compile time GOPATH
-	// at runtime, but we can infer the number of path segments in the GOPATH.
-	// We note that runtime.Func.Name() returns the function name qualified by
-	// the import path, which does not include the GOPATH. Thus we can trim
-	// segments from the beginning of the file path until the number of path
-	// separators remaining is one more than the number of path separators in
-	// the function name. For example, given:
-	//
-	//    GOPATH     /home/user
-	//    file       /home/user/src/pkg/sub/file.go
-	//    fn.Name()  pkg/sub.Type.Method
-	//
-	// We want to produce:
-	//
-	//    file[:idx] == /home/user/src/
-	//    file[idx:] == pkg/sub/file.go
-	//
-	// From this we can easily see that fn.Name() has one less path separator
-	// than our desired result for file[idx:]. We count separators from the
-	// end of the file path until it finds two more than in the function name
-	// and then move one character forward to preserve the initial path
-	// segment without a leading separator.
-	const sep = "/"
-	i := len(file)
-	for n := strings.Count(funcName, sep) + 2; n > 0; n-- {
-		i = strings.LastIndex(file[:i], sep)
-		if i == -1 {
-			i = -len(sep)
-			break
-		}
-	}
-	// get back to 0 or trim the leading separator
-	return i + len(sep)
-}
-
-var runtimePath string
-
-func init() {
-	var pcs [1]uintptr
-	runtime.Callers(0, pcs[:])
-	fn := runtime.FuncForPC(pcs[0])
-	file, _ := fn.FileLine(pcs[0])
-
-	idx := pkgIndex(file, fn.Name())
-
-	runtimePath = file[:idx]
-	if runtime.GOOS == "windows" {
-		runtimePath = strings.ToLower(runtimePath)
-	}
-}
-
-func inGoroot(c Call) bool {
-	file := c.file()
-	if len(file) == 0 || file[0] == '?' {
-		return true
-	}
-	if runtime.GOOS == "windows" {
-		file = strings.ToLower(file)
-	}
-	return strings.HasPrefix(file, runtimePath) || strings.HasSuffix(file, "/_testmain.go")
-}
-
-// TrimRuntime returns a slice of the CallStack with the topmost entries from
-// the go runtime removed. It considers any calls originating from unknown
-// files, files under GOROOT, or _testmain.go as part of the runtime.
-func (cs CallStack) TrimRuntime() CallStack {
-	for len(cs) > 0 && inGoroot(cs[len(cs)-1]) {
-		cs = cs[:len(cs)-1]
-	}
-	return cs
-}

vendor/github.com/influxdata/influxdb/LICENSE

@@ -1,20 +0,0 @@
-The MIT License (MIT)
-
-Copyright (c) 2013-2016 Errplane Inc.
-
-Permission is hereby granted, free of charge, to any person obtaining a copy of
-this software and associated documentation files (the "Software"), to deal in
-the Software without restriction, including without limitation the rights to
-use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
-the Software, and to permit persons to whom the Software is furnished to do so,
-subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
-COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
-IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/influxdata/influxdb/LICENSE_OF_DEPENDENCIES.md

@@ -1,25 +0,0 @@
-# List
-- bootstrap 3.3.5 [MIT LICENSE](https://github.com/twbs/bootstrap/blob/master/LICENSE)
-- collectd.org [ISC LICENSE](https://github.com/collectd/go-collectd/blob/master/LICENSE)
-- github.com/BurntSushi/toml [WTFPL LICENSE](https://github.com/BurntSushi/toml/blob/master/COPYING)
-- github.com/bmizerany/pat [MIT LICENSE](https://github.com/bmizerany/pat#license)
-- github.com/boltdb/bolt [MIT LICENSE](https://github.com/boltdb/bolt/blob/master/LICENSE)
-- github.com/cespare/xxhash [MIT LICENSE](https://github.com/cespare/xxhash/blob/master/LICENSE.txt)
-- github.com/clarkduvall/hyperloglog [MIT LICENSE](https://github.com/clarkduvall/hyperloglog/blob/master/LICENSE)
-- github.com/davecgh/go-spew/spew [ISC LICENSE](https://github.com/davecgh/go-spew/blob/master/LICENSE)
-- github.com/dgrijalva/jwt-go [MIT LICENSE](https://github.com/dgrijalva/jwt-go/blob/master/LICENSE)
-- github.com/dgryski/go-bits [MIT LICENSE](https://github.com/dgryski/go-bits/blob/master/LICENSE)
-- github.com/dgryski/go-bitstream [MIT LICENSE](https://github.com/dgryski/go-bitstream/blob/master/LICENSE)
-- github.com/gogo/protobuf/proto [BSD LICENSE](https://github.com/gogo/protobuf/blob/master/LICENSE)
-- github.com/golang/snappy [BSD LICENSE](https://github.com/golang/snappy/blob/master/LICENSE)
-- github.com/google/go-cmp [BSD LICENSE](https://github.com/google/go-cmp/blob/master/LICENSE)
-- github.com/influxdata/usage-client [MIT LICENSE](https://github.com/influxdata/usage-client/blob/master/LICENSE.txt)
-- github.com/jwilder/encoding [MIT LICENSE](https://github.com/jwilder/encoding/blob/master/LICENSE)
-- github.com/paulbellamy/ratecounter [MIT LICENSE](https://github.com/paulbellamy/ratecounter/blob/master/LICENSE)
-- github.com/peterh/liner [MIT LICENSE](https://github.com/peterh/liner/blob/master/COPYING)
-- github.com/rakyll/statik [APACHE LICENSE](https://github.com/rakyll/statik/blob/master/LICENSE)
-- github.com/retailnext/hllpp [BSD LICENSE](https://github.com/retailnext/hllpp/blob/master/LICENSE)
-- github.com/uber-go/atomic [MIT LICENSE](https://github.com/uber-go/atomic/blob/master/LICENSE.txt)
-- github.com/uber-go/zap [MIT LICENSE](https://github.com/uber-go/zap/blob/master/LICENSE.txt)
-- golang.org/x/crypto [BSD LICENSE](https://github.com/golang/crypto/blob/master/LICENSE)
-- jquery 2.1.4 [MIT LICENSE](https://github.com/jquery/jquery/blob/master/LICENSE.txt)

vendor/github.com/influxdata/influxdb/models/consistency.go

@@ -1,48 +0,0 @@
-package models
-
-import (
-	"errors"
-	"strings"
-)
-
-// ConsistencyLevel represent a required replication criteria before a write can
-// be returned as successful.
-//
-// The consistency level is handled in open-source InfluxDB but only applicable to clusters.
-type ConsistencyLevel int
-
-const (
-	// ConsistencyLevelAny allows for hinted handoff, potentially no write happened yet.
-	ConsistencyLevelAny ConsistencyLevel = iota
-
-	// ConsistencyLevelOne requires at least one data node acknowledged a write.
-	ConsistencyLevelOne
-
-	// ConsistencyLevelQuorum requires a quorum of data nodes to acknowledge a write.
-	ConsistencyLevelQuorum
-
-	// ConsistencyLevelAll requires all data nodes to acknowledge a write.
-	ConsistencyLevelAll
-)
-
-var (
-	// ErrInvalidConsistencyLevel is returned when parsing the string version
-	// of a consistency level.
-	ErrInvalidConsistencyLevel = errors.New("invalid consistency level")
-)
-
-// ParseConsistencyLevel converts a consistency level string to the corresponding ConsistencyLevel const.
-func ParseConsistencyLevel(level string) (ConsistencyLevel, error) {
-	switch strings.ToLower(level) {
-	case "any":
-		return ConsistencyLevelAny, nil
-	case "one":
-		return ConsistencyLevelOne, nil
-	case "quorum":
-		return ConsistencyLevelQuorum, nil
-	case "all":
-		return ConsistencyLevelAll, nil
-	default:
-		return 0, ErrInvalidConsistencyLevel
-	}
-}

vendor/github.com/influxdata/influxdb1-client/LICENSE

@@ -1,6 +1,6 @@
-The MIT License (MIT)
+MIT License
 
-Copyright (c) 2014 Chris Hines
+Copyright (c) 2019 InfluxData
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

vendor/github.com/influxdata/influxdb1-client/models/inline_fnv.go

@@ -1,4 +1,4 @@
-package models // import "github.com/influxdata/influxdb/models"
+package models // import "github.com/influxdata/influxdb1-client/models"
 
 // from stdlib hash/fnv/fnv.go
 const (

vendor/github.com/influxdata/influxdb1-client/models/inline_strconv_parse.go

@@ -1,4 +1,4 @@
-package models // import "github.com/influxdata/influxdb/models"
+package models // import "github.com/influxdata/influxdb1-client/models"
 
 import (
 	"reflect"
@@ -12,6 +12,12 @@ func parseIntBytes(b []byte, base int, bitSize int) (i int64, err error) {
 	return strconv.ParseInt(s, base, bitSize)
 }
 
+// parseUintBytes is a zero-alloc wrapper around strconv.ParseUint.
+func parseUintBytes(b []byte, base int, bitSize int) (i uint64, err error) {
+	s := unsafeBytesToString(b)
+	return strconv.ParseUint(s, base, bitSize)
+}
+
 // parseFloatBytes is a zero-alloc wrapper around strconv.ParseFloat.
 func parseFloatBytes(b []byte, bitSize int) (float64, error) {
 	s := unsafeBytesToString(b)

vendor/github.com/influxdata/influxdb1-client/models/points.go

@@ -1,5 +1,5 @@
 // Package models implements basic objects used throughout the TICK stack.
-package models // import "github.com/influxdata/influxdb/models"
+package models // import "github.com/influxdata/influxdb1-client/models"
 
 import (
 	"bytes"
@@ -12,20 +12,27 @@ import (
 	"strconv"
 	"strings"
 	"time"
+	"unicode"
+	"unicode/utf8"
 
-	"github.com/influxdata/influxdb/pkg/escape"
+	"github.com/influxdata/influxdb1-client/pkg/escape"
 )
 
+type escapeSet struct {
+	k   [1]byte
+	esc [2]byte
+}
+
 var (
-	measurementEscapeCodes = map[byte][]byte{
-		',': []byte(`\,`),
-		' ': []byte(`\ `),
+	measurementEscapeCodes = [...]escapeSet{
+		{k: [1]byte{','}, esc: [2]byte{'\\', ','}},
+		{k: [1]byte{' '}, esc: [2]byte{'\\', ' '}},
 	}
 
-	tagEscapeCodes = map[byte][]byte{
-		',': []byte(`\,`),
-		' ': []byte(`\ `),
-		'=': []byte(`\=`),
+	tagEscapeCodes = [...]escapeSet{
+		{k: [1]byte{','}, esc: [2]byte{'\\', ','}},
+		{k: [1]byte{' '}, esc: [2]byte{'\\', ' '}},
+		{k: [1]byte{'='}, esc: [2]byte{'\\', '='}},
 	}
 
 	// ErrPointMustHaveAField is returned when operating on a point that does not have any fields.
@@ -43,6 +50,16 @@ const (
 	MaxKeyLength = 65535
 )
 
+// enableUint64Support will enable uint64 support if set to true.
+var enableUint64Support = false
+
+// EnableUintSupport manually enables uint support for the point parser.
+// This function will be removed in the future and only exists for unit tests during the
+// transition.
+func EnableUintSupport() {
+	enableUint64Support = true
+}
+
 // Point defines the values that will be written to the database.
 type Point interface {
 	// Name return the measurement name for the point.
@@ -54,6 +71,9 @@ type Point interface {
 	// Tags returns the tag set for the point.
 	Tags() Tags
 
+	// ForEachTag iterates over each tag invoking fn.  If fn return false, iteration stops.
+	ForEachTag(fn func(k, v []byte) bool)
+
 	// AddTag adds or replaces a tag value for a point.
 	AddTag(key, value string)
 
@@ -137,6 +157,9 @@ const (
 
 	// Empty is used to indicate that there is no field.
 	Empty
+
+	// Unsigned indicates the field's type is an unsigned integer.
+	Unsigned
 )
 
 // FieldIterator provides a low-allocation interface to iterate through a point's fields.
@@ -156,6 +179,9 @@ type FieldIterator interface {
 	// IntegerValue returns the integer value of the current field.
 	IntegerValue() (int64, error)
 
+	// UnsignedValue returns the unsigned value of the current field.
+	UnsignedValue() (uint64, error)
+
 	// BooleanValue returns the boolean value of the current field.
 	BooleanValue() (bool, error)
 
@@ -205,6 +231,12 @@ type point struct {
 	it fieldIterator
 }
 
+// type assertions
+var (
+	_ Point         = (*point)(nil)
+	_ FieldIterator = (*point)(nil)
+)
+
 const (
 	// the number of characters for the largest possible int64 (9223372036854775807)
 	maxInt64Digits = 19
@@ -212,6 +244,9 @@ const (
 	// the number of characters for the smallest possible int64 (-9223372036854775808)
 	minInt64Digits = 20
 
+	// the number of characters for the largest possible uint64 (18446744073709551615)
+	maxUint64Digits = 20
+
 	// the number of characters required for the largest float64 before a range check
 	// would occur during parsing
 	maxFloat64Digits = 25
@@ -238,31 +273,46 @@ func ParsePointsString(buf string) ([]Point, error) {
 // NOTE: to minimize heap allocations, the returned Tags will refer to subslices of buf.
 // This can have the unintended effect preventing buf from being garbage collected.
 func ParseKey(buf []byte) (string, Tags) {
+	name, tags := ParseKeyBytes(buf)
+	return string(name), tags
+}
+
+func ParseKeyBytes(buf []byte) ([]byte, Tags) {
+	return ParseKeyBytesWithTags(buf, nil)
+}
+
+func ParseKeyBytesWithTags(buf []byte, tags Tags) ([]byte, Tags) {
 	// Ignore the error because scanMeasurement returns "missing fields" which we ignore
 	// when just parsing a key
 	state, i, _ := scanMeasurement(buf, 0)
 
-	var tags Tags
+	var name []byte
 	if state == tagKeyState {
-		tags = parseTags(buf)
+		tags = parseTags(buf, tags)
 		// scanMeasurement returns the location of the comma if there are tags, strip that off
-		return string(buf[:i-1]), tags
+		name = buf[:i-1]
+	} else {
+		name = buf[:i]
 	}
-	return string(buf[:i]), tags
+	return unescapeMeasurement(name), tags
 }
 
-func ParseTags(buf []byte) (Tags, error) {
-	return parseTags(buf), nil
+func ParseTags(buf []byte) Tags {
+	return parseTags(buf, nil)
 }
 
-func ParseName(buf []byte) ([]byte, error) {
+func ParseName(buf []byte) []byte {
 	// Ignore the error because scanMeasurement returns "missing fields" which we ignore
 	// when just parsing a key
 	state, i, _ := scanMeasurement(buf, 0)
+	var name []byte
 	if state == tagKeyState {
-		return buf[:i-1], nil
+		name = buf[:i-1]
+	} else {
+		name = buf[:i]
 	}
-	return buf[:i], nil
+
+	return unescapeMeasurement(name)
 }
 
 // ParsePointsWithPrecision is similar to ParsePoints, but allows the
@@ -285,7 +335,6 @@ func ParsePointsWithPrecision(buf []byte, defaultTime time.Time, precision strin
 			continue
 		}
 
-		// lines which start with '#' are comments
 		start := skipWhitespace(block, 0)
 
 		// If line is all whitespace, just skip it
@@ -293,6 +342,7 @@ func ParsePointsWithPrecision(buf []byte, defaultTime time.Time, precision strin
 			continue
 		}
 
+		// lines which start with '#' are comments
 		if block[start] == '#' {
 			continue
 		}
@@ -318,7 +368,7 @@ func ParsePointsWithPrecision(buf []byte, defaultTime time.Time, precision strin
 }
 
 func parsePoint(buf []byte, defaultTime time.Time, precision string) (Point, error) {
-	// scan the first block which is measurement[,tag1=value1,tag2=value=2...]
+	// scan the first block which is measurement[,tag1=value1,tag2=value2...]
 	pos, key, err := scanKey(buf, 0)
 	if err != nil {
 		return nil, err
@@ -345,7 +395,7 @@ func parsePoint(buf []byte, defaultTime time.Time, precision string) (Point, err
 	}
 
 	var maxKeyErr error
-	walkFields(fields, func(k, v []byte) bool {
+	err = walkFields(fields, func(k, v []byte) bool {
 		if sz := seriesKeySize(key, k); sz > MaxKeyLength {
 			maxKeyErr = fmt.Errorf("max key length exceeded: %v > %v", sz, MaxKeyLength)
 			return false
@@ -353,6 +403,10 @@ func parsePoint(buf []byte, defaultTime time.Time, precision string) (Point, err
 		return true
 	})
 
+	if err != nil {
+		return nil, err
+	}
+
 	if maxKeyErr != nil {
 		return nil, maxKeyErr
 	}
@@ -815,7 +869,7 @@ func isNumeric(b byte) bool {
 // error if a invalid number is scanned.
 func scanNumber(buf []byte, i int) (int, error) {
 	start := i
-	var isInt bool
+	var isInt, isUnsigned bool
 
 	// Is negative number?
 	if i < len(buf) && buf[i] == '-' {
@@ -841,10 +895,14 @@ func scanNumber(buf []byte, i int) (int, error) {
 			break
 		}
 
-		if buf[i] == 'i' && i > start && !isInt {
+		if buf[i] == 'i' && i > start && !(isInt || isUnsigned) {
 			isInt = true
 			i++
 			continue
+		} else if buf[i] == 'u' && i > start && !(isInt || isUnsigned) {
+			isUnsigned = true
+			i++
+			continue
 		}
 
 		if buf[i] == '.' {
@@ -879,7 +937,7 @@ func scanNumber(buf []byte, i int) (int, error) {
 		i++
 	}
 
-	if isInt && (decimal || scientific) {
+	if (isInt || isUnsigned) && (decimal || scientific) {
 		return i, ErrInvalidNumber
 	}
 
@@ -914,6 +972,26 @@ func scanNumber(buf []byte, i int) (int, error) {
 				return i, fmt.Errorf("unable to parse integer %s: %s", buf[start:i-1], err)
 			}
 		}
+	} else if isUnsigned {
+		// Return an error if uint64 support has not been enabled.
+		if !enableUint64Support {
+			return i, ErrInvalidNumber
+		}
+		// Make sure the last char is a 'u' for unsigned
+		if buf[i-1] != 'u' {
+			return i, ErrInvalidNumber
+		}
+		// Make sure the first char is not a '-' for unsigned
+		if buf[start] == '-' {
+			return i, ErrInvalidNumber
+		}
+		// Parse the uint to check bounds the number of digits could be larger than the max range
+		// We subtract 1 from the index to remove the `u` from our tests
+		if len(buf[start:i-1]) >= maxUint64Digits {
+			if _, err := parseUintBytes(buf[start:i-1], 10, 64); err != nil {
+				return i, fmt.Errorf("unable to parse unsigned %s: %s", buf[start:i-1], err)
+			}
+		}
 	} else {
 		// Parse the float to check bounds if it's scientific or the number of digits could be larger than the max range
 		if scientific || len(buf[start:i]) >= maxFloat64Digits || len(buf[start:i]) >= minFloat64Digits {
@@ -1015,7 +1093,7 @@ func scanLine(buf []byte, i int) (int, []byte) {
 		}
 
 		// skip past escaped characters
-		if buf[i] == '\\' {
+		if buf[i] == '\\' && i+2 < len(buf) {
 			i += 2
 			continue
 		}
@@ -1144,24 +1222,34 @@ func scanFieldValue(buf []byte, i int) (int, []byte) {
 	return i, buf[start:i]
 }
 
-func escapeMeasurement(in []byte) []byte {
-	for b, esc := range measurementEscapeCodes {
-		in = bytes.Replace(in, []byte{b}, esc, -1)
+func EscapeMeasurement(in []byte) []byte {
+	for _, c := range measurementEscapeCodes {
+		if bytes.IndexByte(in, c.k[0]) != -1 {
+			in = bytes.Replace(in, c.k[:], c.esc[:], -1)
+		}
 	}
 	return in
 }
 
 func unescapeMeasurement(in []byte) []byte {
-	for b, esc := range measurementEscapeCodes {
-		in = bytes.Replace(in, esc, []byte{b}, -1)
+	if bytes.IndexByte(in, '\\') == -1 {
+		return in
+	}
+
+	for i := range measurementEscapeCodes {
+		c := &measurementEscapeCodes[i]
+		if bytes.IndexByte(in, c.k[0]) != -1 {
+			in = bytes.Replace(in, c.esc[:], c.k[:], -1)
+		}
 	}
 	return in
 }
 
 func escapeTag(in []byte) []byte {
-	for b, esc := range tagEscapeCodes {
-		if bytes.IndexByte(in, b) != -1 {
-			in = bytes.Replace(in, []byte{b}, esc, -1)
+	for i := range tagEscapeCodes {
+		c := &tagEscapeCodes[i]
+		if bytes.IndexByte(in, c.k[0]) != -1 {
+			in = bytes.Replace(in, c.k[:], c.esc[:], -1)
 		}
 	}
 	return in
@@ -1172,9 +1260,10 @@ func unescapeTag(in []byte) []byte {
 		return in
 	}
 
-	for b, esc := range tagEscapeCodes {
-		if bytes.IndexByte(in, b) != -1 {
-			in = bytes.Replace(in, esc, []byte{b}, -1)
+	for i := range tagEscapeCodes {
+		c := &tagEscapeCodes[i]
+		if bytes.IndexByte(in, c.k[0]) != -1 {
+			in = bytes.Replace(in, c.esc[:], c.k[:], -1)
 		}
 	}
 	return in
@@ -1226,7 +1315,8 @@ func unescapeStringField(in string) string {
 }
 
 // NewPoint returns a new point with the given measurement name, tags, fields and timestamp.  If
-// an unsupported field value (NaN) or out of range time is passed, this function returns an error.
+// an unsupported field value (NaN, or +/-Inf) or out of range time is passed, this function
+// returns an error.
 func NewPoint(name string, tags Tags, fields Fields, t time.Time) (Point, error) {
 	key, err := pointKey(name, tags, fields, t)
 	if err != nil {
@@ -1257,11 +1347,17 @@ func pointKey(measurement string, tags Tags, fields Fields, t time.Time) ([]byte
 		switch value := value.(type) {
 		case float64:
 			// Ensure the caller validates and handles invalid field values
+			if math.IsInf(value, 0) {
+				return nil, fmt.Errorf("+/-Inf is an unsupported value for field %s", key)
+			}
 			if math.IsNaN(value) {
 				return nil, fmt.Errorf("NaN is an unsupported value for field %s", key)
 			}
 		case float32:
 			// Ensure the caller validates and handles invalid field values
+			if math.IsInf(float64(value), 0) {
+				return nil, fmt.Errorf("+/-Inf is an unsupported value for field %s", key)
+			}
 			if math.IsNaN(float64(value)) {
 				return nil, fmt.Errorf("NaN is an unsupported value for field %s", key)
 			}
@@ -1315,6 +1411,11 @@ func NewPointFromBytes(b []byte) (Point, error) {
 			if err != nil {
 				return nil, fmt.Errorf("unable to unmarshal field %s: %s", string(iter.FieldKey()), err)
 			}
+		case Unsigned:
+			_, err := iter.UnsignedValue()
+			if err != nil {
+				return nil, fmt.Errorf("unable to unmarshal field %s: %s", string(iter.FieldKey()), err)
+			}
 		case String:
 			// Skip since this won't return an error
 		case Boolean:
@@ -1382,10 +1483,14 @@ func (p *point) Tags() Tags {
 	if p.cachedTags != nil {
 		return p.cachedTags
 	}
-	p.cachedTags = parseTags(p.key)
+	p.cachedTags = parseTags(p.key, nil)
 	return p.cachedTags
 }
 
+func (p *point) ForEachTag(fn func(k, v []byte) bool) {
+	walkTags(p.key, fn)
+}
+
 func (p *point) HasTag(tag []byte) bool {
 	if len(p.key) == 0 {
 		return false
@@ -1445,11 +1550,14 @@ func walkTags(buf []byte, fn func(key, value []byte) bool) {
 
 // walkFields walks each field key and value via fn.  If fn returns false, the iteration
 // is stopped.  The values are the raw byte slices and not the converted types.
-func walkFields(buf []byte, fn func(key, value []byte) bool) {
+func walkFields(buf []byte, fn func(key, value []byte) bool) error {
 	var i int
 	var key, val []byte
 	for len(buf) > 0 {
 		i, key = scanTo(buf, 0, '=')
+		if i > len(buf)-2 {
+			return fmt.Errorf("invalid value: field-key=%s", key)
+		}
 		buf = buf[i+1:]
 		i, val = scanFieldValue(buf, 0)
 		buf = buf[i:]
@@ -1462,26 +1570,52 @@ func walkFields(buf []byte, fn func(key, value []byte) bool) {
 			buf = buf[1:]
 		}
 	}
+	return nil
 }
 
-func parseTags(buf []byte) Tags {
+// parseTags parses buf into the provided destination tags, returning destination
+// Tags, which may have a different length and capacity.
+func parseTags(buf []byte, dst Tags) Tags {
 	if len(buf) == 0 {
 		return nil
 	}
 
-	tags := make(Tags, 0, bytes.Count(buf, []byte(",")))
+	n := bytes.Count(buf, []byte(","))
+	if cap(dst) < n {
+		dst = make(Tags, n)
+	} else {
+		dst = dst[:n]
+	}
+
+	// Ensure existing behaviour when point has no tags and nil slice passed in.
+	if dst == nil {
+		dst = Tags{}
+	}
+
+	// Series keys can contain escaped commas, therefore the number of commas
+	// in a series key only gives an estimation of the upper bound on the number
+	// of tags.
+	var i int
 	walkTags(buf, func(key, value []byte) bool {
-		tags = append(tags, NewTag(key, value))
+		dst[i].Key, dst[i].Value = key, value
+		i++
 		return true
 	})
-	return tags
+	return dst[:i]
 }
 
 // MakeKey creates a key for a set of tags.
 func MakeKey(name []byte, tags Tags) []byte {
+	return AppendMakeKey(nil, name, tags)
+}
+
+// AppendMakeKey appends the key derived from name and tags to dst and returns the extended buffer.
+func AppendMakeKey(dst []byte, name []byte, tags Tags) []byte {
 	// unescape the name and then re-escape it to avoid double escaping.
 	// The key should always be stored in escaped form.
-	return append(escapeMeasurement(unescapeMeasurement(name)), tags.HashKey()...)
+	dst = append(dst, EscapeMeasurement(unescapeMeasurement(name))...)
+	dst = tags.AppendHashKey(dst)
+	return dst
 }
 
 // SetTags replaces the tags for the point.
@@ -1630,10 +1764,7 @@ func (p *point) UnmarshalBinary(b []byte) error {
 	p.fields, b = b[:n], b[n:]
 
 	// Read timestamp.
-	if err := p.time.UnmarshalBinary(b); err != nil {
-		return err
-	}
-	return nil
+	return p.time.UnmarshalBinary(b)
 }
 
 // PrecisionString returns a string representation of the point. If there
@@ -1678,6 +1809,12 @@ func (p *point) unmarshalBinary() (Fields, error) {
 				return nil, fmt.Errorf("unable to unmarshal field %s: %s", string(iter.FieldKey()), err)
 			}
 			fields[string(iter.FieldKey())] = v
+		case Unsigned:
+			v, err := iter.UnsignedValue()
+			if err != nil {
+				return nil, fmt.Errorf("unable to unmarshal field %s: %s", string(iter.FieldKey()), err)
+			}
+			fields[string(iter.FieldKey())] = v
 		case String:
 			fields[string(iter.FieldKey())] = iter.StringValue()
 		case Boolean:
@@ -1708,7 +1845,7 @@ func (p *point) UnixNano() int64 {
 // string representations are no longer than size. Points with a single field or
 // a point without a timestamp may exceed the requested size.
 func (p *point) Split(size int) []Point {
-	if p.time.IsZero() || len(p.String()) <= size {
+	if p.time.IsZero() || p.StringSize() <= size {
 		return []Point{p}
 	}
 
@@ -1803,6 +1940,82 @@ func NewTags(m map[string]string) Tags {
 	return a
 }
 
+// HashKey hashes all of a tag's keys.
+func (a Tags) HashKey() []byte {
+	return a.AppendHashKey(nil)
+}
+
+func (a Tags) needsEscape() bool {
+	for i := range a {
+		t := &a[i]
+		for j := range tagEscapeCodes {
+			c := &tagEscapeCodes[j]
+			if bytes.IndexByte(t.Key, c.k[0]) != -1 || bytes.IndexByte(t.Value, c.k[0]) != -1 {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// AppendHashKey appends the result of hashing all of a tag's keys and values to dst and returns the extended buffer.
+func (a Tags) AppendHashKey(dst []byte) []byte {
+	// Empty maps marshal to empty bytes.
+	if len(a) == 0 {
+		return dst
+	}
+
+	// Type invariant: Tags are sorted
+
+	sz := 0
+	var escaped Tags
+	if a.needsEscape() {
+		var tmp [20]Tag
+		if len(a) < len(tmp) {
+			escaped = tmp[:len(a)]
+		} else {
+			escaped = make(Tags, len(a))
+		}
+
+		for i := range a {
+			t := &a[i]
+			nt := &escaped[i]
+			nt.Key = escapeTag(t.Key)
+			nt.Value = escapeTag(t.Value)
+			sz += len(nt.Key) + len(nt.Value)
+		}
+	} else {
+		sz = a.Size()
+		escaped = a
+	}
+
+	sz += len(escaped) + (len(escaped) * 2) // separators
+
+	// Generate marshaled bytes.
+	if cap(dst)-len(dst) < sz {
+		nd := make([]byte, len(dst), len(dst)+sz)
+		copy(nd, dst)
+		dst = nd
+	}
+	buf := dst[len(dst) : len(dst)+sz]
+	idx := 0
+	for i := range escaped {
+		k := &escaped[i]
+		if len(k.Value) == 0 {
+			continue
+		}
+		buf[idx] = ','
+		idx++
+		copy(buf[idx:], k.Key)
+		idx += len(k.Key)
+		buf[idx] = '='
+		idx++
+		copy(buf[idx:], k.Value)
+		idx += len(k.Value)
+	}
+	return dst[:len(dst)+idx]
+}
+
 // String returns the string representation of the tags.
 func (a Tags) String() string {
 	var buf bytes.Buffer
@@ -1822,8 +2035,8 @@ func (a Tags) String() string {
 // for data structures or delimiters for example.
 func (a Tags) Size() int {
 	var total int
-	for _, t := range a {
-		total += t.Size()
+	for i := range a {
+		total += a[i].Size()
 	}
 	return total
 }
@@ -1919,18 +2132,6 @@ func (a *Tags) SetString(key, value string) {
 	a.Set([]byte(key), []byte(value))
 }
 
-// Delete removes a tag by key.
-func (a *Tags) Delete(key []byte) {
-	for i, t := range *a {
-		if bytes.Equal(t.Key, key) {
-			copy((*a)[i:], (*a)[i+1:])
-			(*a)[len(*a)-1] = Tag{}
-			*a = (*a)[:len(*a)-1]
-			return
-		}
-	}
-}
-
 // Map returns a map representation of the tags.
 func (a Tags) Map() map[string]string {
 	m := make(map[string]string, len(a))
@@ -1940,60 +2141,6 @@ func (a Tags) Map() map[string]string {
 	return m
 }
 
-// Merge merges the tags combining the two. If both define a tag with the
-// same key, the merged value overwrites the old value.
-// A new map is returned.
-func (a Tags) Merge(other map[string]string) Tags {
-	merged := make(map[string]string, len(a)+len(other))
-	for _, t := range a {
-		merged[string(t.Key)] = string(t.Value)
-	}
-	for k, v := range other {
-		merged[k] = v
-	}
-	return NewTags(merged)
-}
-
-// HashKey hashes all of a tag's keys.
-func (a Tags) HashKey() []byte {
-	// Empty maps marshal to empty bytes.
-	if len(a) == 0 {
-		return nil
-	}
-
-	// Type invariant: Tags are sorted
-
-	escaped := make(Tags, 0, len(a))
-	sz := 0
-	for _, t := range a {
-		ek := escapeTag(t.Key)
-		ev := escapeTag(t.Value)
-
-		if len(ev) > 0 {
-			escaped = append(escaped, Tag{Key: ek, Value: ev})
-			sz += len(ek) + len(ev)
-		}
-	}
-
-	sz += len(escaped) + (len(escaped) * 2) // separators
-
-	// Generate marshaled bytes.
-	b := make([]byte, sz)
-	buf := b
-	idx := 0
-	for _, k := range escaped {
-		buf[idx] = ','
-		idx++
-		copy(buf[idx:idx+len(k.Key)], k.Key)
-		idx += len(k.Key)
-		buf[idx] = '='
-		idx++
-		copy(buf[idx:idx+len(k.Value)], k.Value)
-		idx += len(k.Value)
-	}
-	return b[:idx]
-}
-
 // CopyTags returns a shallow copy of tags.
 func CopyTags(a Tags) Tags {
 	other := make(Tags, len(a))
@@ -2071,10 +2218,13 @@ func (p *point) Next() bool {
 		return true
 	}
 
-	if strings.IndexByte(`0123456789-.nNiI`, c) >= 0 {
+	if strings.IndexByte(`0123456789-.nNiIu`, c) >= 0 {
 		if p.it.valueBuf[len(p.it.valueBuf)-1] == 'i' {
 			p.it.fieldType = Integer
 			p.it.valueBuf = p.it.valueBuf[:len(p.it.valueBuf)-1]
+		} else if p.it.valueBuf[len(p.it.valueBuf)-1] == 'u' {
+			p.it.fieldType = Unsigned
+			p.it.valueBuf = p.it.valueBuf[:len(p.it.valueBuf)-1]
 		} else {
 			p.it.fieldType = Float
 		}
@@ -2110,6 +2260,15 @@ func (p *point) IntegerValue() (int64, error) {
 	return n, nil
 }
 
+// UnsignedValue returns the unsigned value of the current field.
+func (p *point) UnsignedValue() (uint64, error) {
+	n, err := parseUintBytes(p.it.valueBuf, 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("unable to parse unsigned value %q: %v", p.it.valueBuf, err)
+	}
+	return n, nil
+}
+
 // BooleanValue returns the boolean value of the current field.
 func (p *point) BooleanValue() (bool, error) {
 	b, err := parseBoolBytes(p.it.valueBuf)
@@ -2192,6 +2351,9 @@ func appendField(b []byte, k string, v interface{}) []byte {
 	case int:
 		b = strconv.AppendInt(b, int64(v), 10)
 		b = append(b, 'i')
+	case uint64:
+		b = strconv.AppendUint(b, v, 10)
+		b = append(b, 'u')
 	case uint32:
 		b = strconv.AppendInt(b, int64(v), 10)
 		b = append(b, 'i')
@@ -2201,10 +2363,9 @@ func appendField(b []byte, k string, v interface{}) []byte {
 	case uint8:
 		b = strconv.AppendInt(b, int64(v), 10)
 		b = append(b, 'i')
-	// TODO: 'uint' should be considered just as "dangerous" as a uint64,
-	// perhaps the value should be checked and capped at MaxInt64? We could
-	// then include uint64 as an accepted value
 	case uint:
+		// TODO: 'uint' should be converted to writing as an unsigned integer,
+		// but we cannot since that would break backwards compatibility.
 		b = strconv.AppendInt(b, int64(v), 10)
 		b = append(b, 'i')
 	case float32:
@@ -2224,8 +2385,29 @@ func appendField(b []byte, k string, v interface{}) []byte {
 	return b
 }
 
-type byteSlices [][]byte
+// ValidKeyToken returns true if the token used for measurement, tag key, or tag
+// value is a valid unicode string and only contains printable, non-replacement characters.
+func ValidKeyToken(s string) bool {
+	if !utf8.ValidString(s) {
+		return false
+	}
+	for _, r := range s {
+		if !unicode.IsPrint(r) || r == unicode.ReplacementChar {
+			return false
+		}
+	}
+	return true
+}
 
-func (a byteSlices) Len() int           { return len(a) }
-func (a byteSlices) Less(i, j int) bool { return bytes.Compare(a[i], a[j]) == -1 }
-func (a byteSlices) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+// ValidKeyTokens returns true if the measurement name and all tags are valid.
+func ValidKeyTokens(name string, tags Tags) bool {
+	if !ValidKeyToken(name) {
+		return false
+	}
+	for _, tag := range tags {
+		if !ValidKeyToken(string(tag.Key)) || !ValidKeyToken(string(tag.Value)) {
+			return false
+		}
+	}
+	return true
+}

vendor/github.com/influxdata/influxdb1-client/models/uint_support.go

@@ -0,0 +1,7 @@
+// +build uint uint64
+
+package models
+
+func init() {
+	EnableUintSupport()
+}

vendor/github.com/influxdata/influxdb1-client/pkg/escape/bytes.go

@@ -1,6 +1,6 @@
 // Package escape contains utilities for escaping parts of InfluxQL
 // and InfluxDB line protocol.
-package escape // import "github.com/influxdata/influxdb/pkg/escape"
+package escape // import "github.com/influxdata/influxdb1-client/pkg/escape"
 
 import (
 	"bytes"
@@ -78,7 +78,11 @@ func Unescape(in []byte) []byte {
 
 	i := 0
 	inLen := len(in)
-	var out []byte
+
+	// The output size will be no more than inLen. Preallocating the
+	// capacity of the output is faster and uses less memory than
+	// letting append() do its own (over)allocation.
+	out := make([]byte, 0, inLen)
 
 	for {
 		if i >= inLen {

vendor/github.com/influxdata/influxdb1-client/v2/client.go

@@ -1,5 +1,5 @@
 // Package client (v2) is the current official Go client for InfluxDB.
-package client // import "github.com/influxdata/influxdb/client/v2"
+package client // import "github.com/influxdata/influxdb1-client/v2"
 
 import (
 	"bytes"
@@ -9,13 +9,15 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"mime"
 	"net/http"
 	"net/url"
+	"path"
 	"strconv"
 	"strings"
 	"time"
 
-	"github.com/influxdata/influxdb/models"
+	"github.com/influxdata/influxdb1-client/models"
 )
 
 // HTTPConfig is the config data needed to create an HTTP Client.
@@ -43,6 +45,9 @@ type HTTPConfig struct {
 	// TLSConfig allows the user to set their own TLS config for the HTTP
 	// Client. If set, this option overrides InsecureSkipVerify.
 	TLSConfig *tls.Config
+
+	// Proxy configures the Proxy function on the HTTP client.
+	Proxy func(req *http.Request) (*url.URL, error)
 }
 
 // BatchPointsConfig is the config data needed to create an instance of the BatchPoints struct.
@@ -73,6 +78,10 @@ type Client interface {
 	// the UDP client.
 	Query(q Query) (*Response, error)
 
+	// QueryAsChunk makes an InfluxDB Query on the database. This will fail if using
+	// the UDP client.
+	QueryAsChunk(q Query) (*ChunkedResponse, error)
+
 	// Close releases any resources a Client may be using.
 	Close() error
 }
@@ -97,6 +106,7 @@ func NewHTTPClient(conf HTTPConfig) (Client, error) {
 		TLSClientConfig: &tls.Config{
 			InsecureSkipVerify: conf.InsecureSkipVerify,
 		},
+		Proxy: conf.Proxy,
 	}
 	if conf.TLSConfig != nil {
 		tr.TLSClientConfig = conf.TLSConfig
@@ -118,8 +128,9 @@ func NewHTTPClient(conf HTTPConfig) (Client, error) {
 // Ping returns how long the request took, the version of the server it connected to, and an error if one occurred.
 func (c *client) Ping(timeout time.Duration) (time.Duration, string, error) {
 	now := time.Now()
+
 	u := c.url
-	u.Path = "ping"
+	u.Path = path.Join(u.Path, "ping")
 
 	req, err := http.NewRequest("GET", u.String(), nil)
 	if err != nil {
@@ -150,7 +161,7 @@ func (c *client) Ping(timeout time.Duration) (time.Duration, string, error) {
 	}
 
 	if resp.StatusCode != http.StatusNoContent {
-		var err = fmt.Errorf(string(body))
+		var err = errors.New(string(body))
 		return 0, "", err
 	}
 
@@ -168,7 +179,7 @@ func (c *client) Close() error {
 // once the client is instantiated.
 type client struct {
 	// N.B - if url.UserInfo is accessed in future modifications to the
-	// methods on client, you will need to syncronise access to url.
+	// methods on client, you will need to synchronize access to url.
 	url        url.URL
 	username   string
 	password   string
@@ -318,8 +329,8 @@ func (p *Point) String() string {
 
 // PrecisionString returns a line-protocol string of the Point,
 // with the timestamp formatted for the given precision.
-func (p *Point) PrecisionString(precison string) string {
-	return p.pt.PrecisionString(precison)
+func (p *Point) PrecisionString(precision string) string {
+	return p.pt.PrecisionString(precision)
 }
 
 // Name returns the measurement name of the point.
@@ -356,6 +367,9 @@ func (c *client) Write(bp BatchPoints) error {
 	var b bytes.Buffer
 
 	for _, p := range bp.Points() {
+		if p == nil {
+			continue
+		}
 		if _, err := b.WriteString(p.pt.PrecisionString(bp.Precision())); err != nil {
 			return err
 		}
@@ -366,7 +380,8 @@ func (c *client) Write(bp BatchPoints) error {
 	}
 
 	u := c.url
-	u.Path = "write"
+	u.Path = path.Join(u.Path, "write")
+
 	req, err := http.NewRequest("POST", u.String(), &b)
 	if err != nil {
 		return err
@@ -396,7 +411,7 @@ func (c *client) Write(bp BatchPoints) error {
 	}
 
 	if resp.StatusCode != http.StatusNoContent && resp.StatusCode != http.StatusOK {
-		var err = fmt.Errorf(string(body))
+		var err = errors.New(string(body))
 		return err
 	}
 
@@ -405,12 +420,13 @@ func (c *client) Write(bp BatchPoints) error {
 
 // Query defines a query to send to the server.
 type Query struct {
-	Command    string
-	Database   string
-	Precision  string
-	Chunked    bool
-	ChunkSize  int
-	Parameters map[string]interface{}
+	Command         string
+	Database        string
+	RetentionPolicy string
+	Precision       string
+	Chunked         bool
+	ChunkSize       int
+	Parameters      map[string]interface{}
 }
 
 // NewQuery returns a query object.
@@ -424,6 +440,19 @@ func NewQuery(command, database, precision string) Query {
 	}
 }
 
+// NewQueryWithRP returns a query object.
+// The database, retention policy, and precision arguments can be empty strings if they are not needed
+// for the query. Setting the retention policy only works on InfluxDB versions 1.6 or greater.
+func NewQueryWithRP(command, database, retentionPolicy, precision string) Query {
+	return Query{
+		Command:         command,
+		Database:        database,
+		RetentionPolicy: retentionPolicy,
+		Precision:       precision,
+		Parameters:      make(map[string]interface{}),
+	}
+}
+
 // NewQueryWithParameters returns a query object.
 // The database and precision arguments can be empty strings if they are not needed for the query.
 // parameters is a map of the parameter names used in the command to their values.
@@ -446,11 +475,11 @@ type Response struct {
 // It returns nil if no errors occurred on any statements.
 func (r *Response) Error() error {
 	if r.Err != "" {
-		return fmt.Errorf(r.Err)
+		return errors.New(r.Err)
 	}
 	for _, result := range r.Results {
 		if result.Err != "" {
-			return fmt.Errorf(result.Err)
+			return errors.New(result.Err)
 		}
 	}
 	return nil
@@ -471,55 +500,37 @@ type Result struct {
 
 // Query sends a command to the server and returns the Response.
 func (c *client) Query(q Query) (*Response, error) {
-	u := c.url
-	u.Path = "query"
-
-	jsonParameters, err := json.Marshal(q.Parameters)
-
+	req, err := c.createDefaultRequest(q)
 	if err != nil {
 		return nil, err
 	}
-
-	req, err := http.NewRequest("POST", u.String(), nil)
-	if err != nil {
-		return nil, err
-	}
-
-	req.Header.Set("Content-Type", "")
-	req.Header.Set("User-Agent", c.useragent)
-
-	if c.username != "" {
-		req.SetBasicAuth(c.username, c.password)
-	}
-
 	params := req.URL.Query()
-	params.Set("q", q.Command)
-	params.Set("db", q.Database)
-	params.Set("params", string(jsonParameters))
 	if q.Chunked {
 		params.Set("chunked", "true")
 		if q.ChunkSize > 0 {
 			params.Set("chunk_size", strconv.Itoa(q.ChunkSize))
 		}
+		req.URL.RawQuery = params.Encode()
 	}
-
-	if q.Precision != "" {
-		params.Set("epoch", q.Precision)
-	}
-	req.URL.RawQuery = params.Encode()
-
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
 		return nil, err
 	}
 	defer resp.Body.Close()
 
+	if err := checkResponse(resp); err != nil {
+		return nil, err
+	}
+
 	var response Response
 	if q.Chunked {
 		cr := NewChunkedResponse(resp.Body)
 		for {
 			r, err := cr.NextResponse()
 			if err != nil {
+				if err == io.EOF {
+					break
+				}
 				// If we got an error while decoding the response, send that back.
 				return nil, err
 			}
@@ -548,19 +559,108 @@ func (c *client) Query(q Query) (*Response, error) {
 			return nil, fmt.Errorf("unable to decode json: received status code %d err: %s", resp.StatusCode, decErr)
 		}
 	}
+
 	// If we don't have an error in our json response, and didn't get statusOK
 	// then send back an error
 	if resp.StatusCode != http.StatusOK && response.Error() == nil {
-		return &response, fmt.Errorf("received status code %d from server",
-			resp.StatusCode)
+		return &response, fmt.Errorf("received status code %d from server", resp.StatusCode)
 	}
 	return &response, nil
 }
 
+// QueryAsChunk sends a command to the server and returns the Response.
+func (c *client) QueryAsChunk(q Query) (*ChunkedResponse, error) {
+	req, err := c.createDefaultRequest(q)
+	if err != nil {
+		return nil, err
+	}
+	params := req.URL.Query()
+	params.Set("chunked", "true")
+	if q.ChunkSize > 0 {
+		params.Set("chunk_size", strconv.Itoa(q.ChunkSize))
+	}
+	req.URL.RawQuery = params.Encode()
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := checkResponse(resp); err != nil {
+		return nil, err
+	}
+	return NewChunkedResponse(resp.Body), nil
+}
+
+func checkResponse(resp *http.Response) error {
+	// If we lack a X-Influxdb-Version header, then we didn't get a response from influxdb
+	// but instead some other service. If the error code is also a 500+ code, then some
+	// downstream loadbalancer/proxy/etc had an issue and we should report that.
+	if resp.Header.Get("X-Influxdb-Version") == "" && resp.StatusCode >= http.StatusInternalServerError {
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil || len(body) == 0 {
+			return fmt.Errorf("received status code %d from downstream server", resp.StatusCode)
+		}
+
+		return fmt.Errorf("received status code %d from downstream server, with response body: %q", resp.StatusCode, body)
+	}
+
+	// If we get an unexpected content type, then it is also not from influx direct and therefore
+	// we want to know what we received and what status code was returned for debugging purposes.
+	if cType, _, _ := mime.ParseMediaType(resp.Header.Get("Content-Type")); cType != "application/json" {
+		// Read up to 1kb of the body to help identify downstream errors and limit the impact of things
+		// like downstream serving a large file
+		body, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1024))
+		if err != nil || len(body) == 0 {
+			return fmt.Errorf("expected json response, got empty body, with status: %v", resp.StatusCode)
+		}
+
+		return fmt.Errorf("expected json response, got %q, with status: %v and response body: %q", cType, resp.StatusCode, body)
+	}
+	return nil
+}
+
+func (c *client) createDefaultRequest(q Query) (*http.Request, error) {
+	u := c.url
+	u.Path = path.Join(u.Path, "query")
+
+	jsonParameters, err := json.Marshal(q.Parameters)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("POST", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Content-Type", "")
+	req.Header.Set("User-Agent", c.useragent)
+
+	if c.username != "" {
+		req.SetBasicAuth(c.username, c.password)
+	}
+
+	params := req.URL.Query()
+	params.Set("q", q.Command)
+	params.Set("db", q.Database)
+	if q.RetentionPolicy != "" {
+		params.Set("rp", q.RetentionPolicy)
+	}
+	params.Set("params", string(jsonParameters))
+
+	if q.Precision != "" {
+		params.Set("epoch", q.Precision)
+	}
+	req.URL.RawQuery = params.Encode()
+
+	return req, nil
+
+}
+
 // duplexReader reads responses and writes it to another writer while
 // satisfying the reader interface.
 type duplexReader struct {
-	r io.Reader
+	r io.ReadCloser
 	w io.Writer
 }
 
@@ -572,6 +672,11 @@ func (r *duplexReader) Read(p []byte) (n int, err error) {
 	return n, err
 }
 
+// Close closes the response.
+func (r *duplexReader) Close() error {
+	return r.r.Close()
+}
+
 // ChunkedResponse represents a response from the server that
 // uses chunking to stream the output.
 type ChunkedResponse struct {
@@ -582,8 +687,12 @@ type ChunkedResponse struct {
 
 // NewChunkedResponse reads a stream and produces responses from the stream.
 func NewChunkedResponse(r io.Reader) *ChunkedResponse {
+	rc, ok := r.(io.ReadCloser)
+	if !ok {
+		rc = ioutil.NopCloser(r)
+	}
 	resp := &ChunkedResponse{}
-	resp.duplex = &duplexReader{r: r, w: &resp.buf}
+	resp.duplex = &duplexReader{r: rc, w: &resp.buf}
 	resp.dec = json.NewDecoder(resp.duplex)
 	resp.dec.UseNumber()
 	return resp
@@ -592,10 +701,9 @@ func NewChunkedResponse(r io.Reader) *ChunkedResponse {
 // NextResponse reads the next line of the stream and returns a response.
 func (r *ChunkedResponse) NextResponse() (*Response, error) {
 	var response Response
-
 	if err := r.dec.Decode(&response); err != nil {
 		if err == io.EOF {
-			return nil, nil
+			return nil, err
 		}
 		// A decoding error happened. This probably means the server crashed
 		// and sent a last-ditch error message to us. Ensure we have read the
@@ -607,3 +715,8 @@ func (r *ChunkedResponse) NextResponse() (*Response, error) {
 	r.buf.Reset()
 	return &response, nil
 }
+
+// Close closes the response.
+func (r *ChunkedResponse) Close() error {
+	return r.duplex.Close()
+}

vendor/github.com/influxdata/influxdb1-client/v2/udp.go

@@ -107,6 +107,10 @@ func (uc *udpclient) Query(q Query) (*Response, error) {
 	return nil, fmt.Errorf("Querying via UDP is not supported")
 }
 
+func (uc *udpclient) QueryAsChunk(q Query) (*ChunkedResponse, error) {
+	return nil, fmt.Errorf("Querying via UDP is not supported")
+}
+
 func (uc *udpclient) Ping(timeout time.Duration) (time.Duration, string, error) {
 	return 0, "", nil
 }

vendor/github.com/prometheus/client_golang/prometheus/build_info.go

@@ -0,0 +1,29 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.12
+
+package prometheus
+
+import "runtime/debug"
+
+// readBuildInfo is a wrapper around debug.ReadBuildInfo for Go 1.12+.
+func readBuildInfo() (path, version, sum string) {
+	path, version, sum = "unknown", "unknown", "unknown"
+	if bi, ok := debug.ReadBuildInfo(); ok {
+		path = bi.Main.Path
+		version = bi.Main.Version
+		sum = bi.Main.Sum
+	}
+	return
+}

vendor/github.com/prometheus/client_golang/prometheus/build_info_pre_1.12.go

@@ -0,0 +1,22 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !go1.12
+
+package prometheus
+
+// readBuildInfo is a wrapper around debug.ReadBuildInfo for Go versions before
+// 1.12. Remove this whole file once the minimum supported Go version is 1.12.
+func readBuildInfo() (path, version, sum string) {
+	return "unknown", "unknown", "unknown"
+}

vendor/github.com/prometheus/client_golang/prometheus/collector.go

@@ -29,27 +29,72 @@ type Collector interface {
 	// collected by this Collector to the provided channel and returns once
 	// the last descriptor has been sent. The sent descriptors fulfill the
 	// consistency and uniqueness requirements described in the Desc
-	// documentation. (It is valid if one and the same Collector sends
-	// duplicate descriptors. Those duplicates are simply ignored. However,
-	// two different Collectors must not send duplicate descriptors.) This
-	// method idempotently sends the same descriptors throughout the
-	// lifetime of the Collector. If a Collector encounters an error while
-	// executing this method, it must send an invalid descriptor (created
-	// with NewInvalidDesc) to signal the error to the registry.
+	// documentation.
+	//
+	// It is valid if one and the same Collector sends duplicate
+	// descriptors. Those duplicates are simply ignored. However, two
+	// different Collectors must not send duplicate descriptors.
+	//
+	// Sending no descriptor at all marks the Collector as “unchecked”,
+	// i.e. no checks will be performed at registration time, and the
+	// Collector may yield any Metric it sees fit in its Collect method.
+	//
+	// This method idempotently sends the same descriptors throughout the
+	// lifetime of the Collector. It may be called concurrently and
+	// therefore must be implemented in a concurrency safe way.
+	//
+	// If a Collector encounters an error while executing this method, it
+	// must send an invalid descriptor (created with NewInvalidDesc) to
+	// signal the error to the registry.
 	Describe(chan<- *Desc)
 	// Collect is called by the Prometheus registry when collecting
 	// metrics. The implementation sends each collected metric via the
 	// provided channel and returns once the last metric has been sent. The
-	// descriptor of each sent metric is one of those returned by
-	// Describe. Returned metrics that share the same descriptor must differ
-	// in their variable label values. This method may be called
-	// concurrently and must therefore be implemented in a concurrency safe
-	// way. Blocking occurs at the expense of total performance of rendering
-	// all registered metrics. Ideally, Collector implementations support
-	// concurrent readers.
+	// descriptor of each sent metric is one of those returned by Describe
+	// (unless the Collector is unchecked, see above). Returned metrics that
+	// share the same descriptor must differ in their variable label
+	// values.
+	//
+	// This method may be called concurrently and must therefore be
+	// implemented in a concurrency safe way. Blocking occurs at the expense
+	// of total performance of rendering all registered metrics. Ideally,
+	// Collector implementations support concurrent readers.
 	Collect(chan<- Metric)
 }
 
+// DescribeByCollect is a helper to implement the Describe method of a custom
+// Collector. It collects the metrics from the provided Collector and sends
+// their descriptors to the provided channel.
+//
+// If a Collector collects the same metrics throughout its lifetime, its
+// Describe method can simply be implemented as:
+//
+//   func (c customCollector) Describe(ch chan<- *Desc) {
+//   	DescribeByCollect(c, ch)
+//   }
+//
+// However, this will not work if the metrics collected change dynamically over
+// the lifetime of the Collector in a way that their combined set of descriptors
+// changes as well. The shortcut implementation will then violate the contract
+// of the Describe method. If a Collector sometimes collects no metrics at all
+// (for example vectors like CounterVec, GaugeVec, etc., which only collect
+// metrics after a metric with a fully specified label set has been accessed),
+// it might even get registered as an unchecked Collector (cf. the Register
+// method of the Registerer interface). Hence, only use this shortcut
+// implementation of Describe if you are certain to fulfill the contract.
+//
+// The Collector example demonstrates a use of DescribeByCollect.
+func DescribeByCollect(c Collector, descs chan<- *Desc) {
+	metrics := make(chan Metric)
+	go func() {
+		c.Collect(metrics)
+		close(metrics)
+	}()
+	for m := range metrics {
+		descs <- m.Desc()
+	}
+}
+
 // selfCollector implements Collector for a single Metric so that the Metric
 // collects itself. Add it as an anonymous field to a struct that implements
 // Metric, and call init with the Metric itself as an argument.

vendor/github.com/prometheus/client_golang/prometheus/counter.go

@@ -15,6 +15,10 @@ package prometheus
 
 import (
 	"errors"
+	"math"
+	"sync/atomic"
+
+	dto "github.com/prometheus/client_model/go"
 )
 
 // Counter is a Metric that represents a single numerical value that only ever
@@ -42,6 +46,14 @@ type Counter interface {
 type CounterOpts Opts
 
 // NewCounter creates a new Counter based on the provided CounterOpts.
+//
+// The returned implementation tracks the counter value in two separate
+// variables, a float64 and a uint64. The latter is used to track calls of the
+// Inc method and calls of the Add method with a value that can be represented
+// as a uint64. This allows atomic increments of the counter with optimal
+// performance. (It is common to have an Inc call in very hot execution paths.)
+// Both internal tracking values are added up in the Write method. This has to
+// be taken into account when it comes to precision and overflow behavior.
 func NewCounter(opts CounterOpts) Counter {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -49,20 +61,58 @@ func NewCounter(opts CounterOpts) Counter {
 		nil,
 		opts.ConstLabels,
 	)
-	result := &counter{value: value{desc: desc, valType: CounterValue, labelPairs: desc.constLabelPairs}}
+	result := &counter{desc: desc, labelPairs: desc.constLabelPairs}
 	result.init(result) // Init self-collection.
 	return result
 }
 
 type counter struct {
-	value
+	// valBits contains the bits of the represented float64 value, while
+	// valInt stores values that are exact integers. Both have to go first
+	// in the struct to guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+	valInt  uint64
+
+	selfCollector
+	desc *Desc
+
+	labelPairs []*dto.LabelPair
+}
+
+func (c *counter) Desc() *Desc {
+	return c.desc
 }
 
 func (c *counter) Add(v float64) {
 	if v < 0 {
 		panic(errors.New("counter cannot decrease in value"))
 	}
-	c.value.Add(v)
+	ival := uint64(v)
+	if float64(ival) == v {
+		atomic.AddUint64(&c.valInt, ival)
+		return
+	}
+
+	for {
+		oldBits := atomic.LoadUint64(&c.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&c.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (c *counter) Inc() {
+	atomic.AddUint64(&c.valInt, 1)
+}
+
+func (c *counter) Write(out *dto.Metric) error {
+	fval := math.Float64frombits(atomic.LoadUint64(&c.valBits))
+	ival := atomic.LoadUint64(&c.valInt)
+	val := fval + float64(ival)
+
+	return populateMetric(CounterValue, val, c.labelPairs, out)
 }
 
 // CounterVec is a Collector that bundles a set of Counters that all share the
@@ -70,16 +120,12 @@ func (c *counter) Add(v float64) {
 // if you want to count the same thing partitioned by various dimensions
 // (e.g. number of HTTP requests, partitioned by response code and
 // method). Create instances with NewCounterVec.
-//
-// CounterVec embeds MetricVec. See there for a full list of methods with
-// detailed documentation.
 type CounterVec struct {
-	*MetricVec
+	*metricVec
 }
 
 // NewCounterVec creates a new CounterVec based on the provided CounterOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
+// partitioned by the given label names.
 func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -88,34 +134,62 @@ func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
 		opts.ConstLabels,
 	)
 	return &CounterVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
-			result := &counter{value: value{
-				desc:       desc,
-				valType:    CounterValue,
-				labelPairs: makeLabelPairs(desc, lvs),
-			}}
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels) {
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
+			}
+			result := &counter{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
 			result.init(result) // Init self-collection.
 			return result
 		}),
 	}
 }
 
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns a Counter and not a
-// Metric so that no type conversion is required.
-func (m *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+// GetMetricWithLabelValues returns the Counter for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Counter is created.
+//
+// It is possible to call this method without using the returned Counter to only
+// create the new Counter but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Counter for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Counter from the CounterVec. In that case,
+// the Counter will still exist, but it will not be exported anymore, even if a
+// Counter with the same label values is created later.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
 	if metric != nil {
 		return metric.(Counter), err
 	}
 	return nil, err
 }
 
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns a Counter and not a Metric so that no
-// type conversion is required.
-func (m *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
+// GetMetricWith returns the Counter for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Counter is created. Implications of
+// creating a Counter without using it and keeping the Counter for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
 	if metric != nil {
 		return metric.(Counter), err
 	}
@@ -123,18 +197,57 @@ func (m *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
 //     myVec.WithLabelValues("404", "GET").Add(42)
-func (m *CounterVec) WithLabelValues(lvs ...string) Counter {
-	return m.MetricVec.WithLabelValues(lvs...).(Counter)
+func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
+	c, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return c
 }
 
 // With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
-func (m *CounterVec) With(labels Labels) Counter {
-	return m.MetricVec.With(labels).(Counter)
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *CounterVec) With(labels Labels) Counter {
+	c, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the CounterVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &CounterVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
 }
 
 // CounterFunc is a Counter whose value is determined at collect time by calling a

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -25,19 +25,6 @@ import (
 	dto "github.com/prometheus/client_model/go"
 )
 
-// reservedLabelPrefix is a prefix which is not legal in user-supplied
-// label names.
-const reservedLabelPrefix = "__"
-
-// Labels represents a collection of label name -> value mappings. This type is
-// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
-// metric vector Collectors, e.g.:
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
-//
-// The other use-case is the specification of constant label pairs in Opts or to
-// create a Desc.
-type Labels map[string]string
-
 // Desc is the descriptor used by every Prometheus Metric. It is essentially
 // the immutable meta-data of a Metric. The normal Metric implementations
 // included in this package manage their Desc under the hood. Users only have to
@@ -80,24 +67,19 @@ type Desc struct {
 
 // NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
 // and will be reported on registration time. variableLabels and constLabels can
-// be nil if no such labels should be set. fqName and help must not be empty.
+// be nil if no such labels should be set. fqName must not be empty.
 //
 // variableLabels only contain the label names. Their label values are variable
 // and therefore not part of the Desc. (They are managed within the Metric.)
 //
 // For constLabels, the label values are constant. Therefore, they are fully
-// specified in the Desc. See the Opts documentation for the implications of
-// constant labels.
+// specified in the Desc. See the Collector example for a usage pattern.
 func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
 	d := &Desc{
 		fqName:         fqName,
 		help:           help,
 		variableLabels: variableLabels,
 	}
-	if help == "" {
-		d.err = errors.New("empty help string")
-		return d
-	}
 	if !model.IsValidMetricName(model.LabelValue(fqName)) {
 		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
 		return d
@@ -111,7 +93,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 	// First add only the const label names and sort them...
 	for labelName := range constLabels {
 		if !checkLabelName(labelName) {
-			d.err = fmt.Errorf("%q is not a valid label name", labelName)
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
 			return d
 		}
 		labelNames = append(labelNames, labelName)
@@ -122,12 +104,18 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 	for _, labelName := range labelNames {
 		labelValues = append(labelValues, constLabels[labelName])
 	}
+	// Validate the const label values. They can't have a wrong cardinality, so
+	// use in len(labelValues) as expectedNumberOfValues.
+	if err := validateLabelValues(labelValues, len(labelValues)); err != nil {
+		d.err = err
+		return d
+	}
 	// Now add the variable label names, but prefix them with something that
 	// cannot be in a regular label name. That prevents matching the label
 	// dimension with a different mix between preset and variable labels.
 	for _, labelName := range variableLabels {
 		if !checkLabelName(labelName) {
-			d.err = fmt.Errorf("%q is not a valid label name", labelName)
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
 			return d
 		}
 		labelNames = append(labelNames, "$"+labelName)
@@ -137,6 +125,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 		d.err = errors.New("duplicate label names")
 		return d
 	}
+
 	vh := hashNew()
 	for _, val := range labelValues {
 		vh = hashAdd(vh, val)
@@ -163,7 +152,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 			Value: proto.String(v),
 		})
 	}
-	sort.Sort(LabelPairSorter(d.constLabelPairs))
+	sort.Sort(labelPairSorter(d.constLabelPairs))
 	return d
 }
 
@@ -193,8 +182,3 @@ func (d *Desc) String() string {
 		d.variableLabels,
 	)
 }
-
-func checkLabelName(l string) bool {
-	return model.LabelName(l).IsValid() &&
-		!strings.HasPrefix(l, reservedLabelPrefix)
-}

vendor/github.com/prometheus/client_golang/prometheus/doc.go

@@ -11,10 +11,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package prometheus provides metrics primitives to instrument code for
-// monitoring. It also offers a registry for metrics. Sub-packages allow to
-// expose the registered metrics via HTTP (package promhttp) or push them to a
-// Pushgateway (package push).
+// Package prometheus is the core instrumentation package. It provides metrics
+// primitives to instrument code for monitoring. It also offers a registry for
+// metrics. Sub-packages allow to expose the registered metrics via HTTP
+// (package promhttp) or push them to a Pushgateway (package push). There is
+// also a sub-package promauto, which provides metrics constructors with
+// automatic registration.
 //
 // All exported functions and methods are safe to be used concurrently unless
 // specified otherwise.
@@ -26,6 +28,7 @@
 //    package main
 //
 //    import (
+//    	"log"
 //    	"net/http"
 //
 //    	"github.com/prometheus/client_golang/prometheus"
@@ -59,7 +62,7 @@
 //    	// The Handler function provides a default handler to expose metrics
 //    	// via an HTTP server. "/metrics" is the usual endpoint for that.
 //    	http.Handle("/metrics", promhttp.Handler())
-//      log.Fatal(http.ListenAndServe(":8080", nil))
+//    	log.Fatal(http.ListenAndServe(":8080", nil))
 //    }
 //
 //
@@ -71,7 +74,10 @@
 // The number of exported identifiers in this package might appear a bit
 // overwhelming. However, in addition to the basic plumbing shown in the example
 // above, you only need to understand the different metric types and their
-// vector versions for basic usage.
+// vector versions for basic usage. Furthermore, if you are not concerned with
+// fine-grained control of when and how to register metrics with the registry,
+// have a look at the promauto package, which will effectively allow you to
+// ignore registration altogether in simple cases.
 //
 // Above, you have already touched the Counter and the Gauge. There are two more
 // advanced metric types: the Summary and Histogram. A more thorough description
@@ -115,7 +121,17 @@
 // NewConstSummary (and their respective Must… versions). That will happen in
 // the Collect method. The Describe method has to return separate Desc
 // instances, representative of the “throw-away” metrics to be created later.
-// NewDesc comes in handy to create those Desc instances.
+// NewDesc comes in handy to create those Desc instances. Alternatively, you
+// could return no Desc at all, which will mark the Collector “unchecked”.  No
+// checks are performed at registration time, but metric consistency will still
+// be ensured at scrape time, i.e. any inconsistencies will lead to scrape
+// errors. Thus, with unchecked Collectors, the responsibility to not collect
+// metrics that lead to inconsistencies in the total scrape result lies with the
+// implementer of the Collector. While this is not a desirable state, it is
+// sometimes necessary. The typical use case is a situation where the exact
+// metrics to be returned by a Collector cannot be predicted at registration
+// time, but the implementer has sufficient knowledge of the whole system to
+// guarantee metric consistency.
 //
 // The Collector example illustrates the use case. You can also look at the
 // source code of the processCollector (mirroring process metrics), the
@@ -144,7 +160,7 @@
 // registry.
 //
 // So far, everything we did operated on the so-called default registry, as it
-// can be found in the global DefaultRegistry variable. With NewRegistry, you
+// can be found in the global DefaultRegisterer variable. With NewRegistry, you
 // can create a custom registry, or you can even implement the Registerer or
 // Gatherer interfaces yourself. The methods Register and Unregister work in the
 // same way on a custom registry as the global functions Register and Unregister
@@ -152,11 +168,11 @@
 //
 // There are a number of uses for custom registries: You can use registries with
 // special properties, see NewPedanticRegistry. You can avoid global state, as
-// it is imposed by the DefaultRegistry. You can use multiple registries at the
-// same time to expose different metrics in different ways. You can use separate
-// registries for testing purposes.
+// it is imposed by the DefaultRegisterer. You can use multiple registries at
+// the same time to expose different metrics in different ways.  You can use
+// separate registries for testing purposes.
 //
-// Also note that the DefaultRegistry comes registered with a Collector for Go
+// Also note that the DefaultRegisterer comes registered with a Collector for Go
 // runtime metrics (via NewGoCollector) and a Collector for process metrics (via
 // NewProcessCollector). With a custom registry, you are in control and decide
 // yourself about the Collectors to register.
@@ -167,7 +183,6 @@
 // method can then expose the gathered metrics in some way. Usually, the metrics
 // are served via HTTP on the /metrics endpoint. That's happening in the example
 // above. The tools to expose metrics via HTTP are in the promhttp sub-package.
-// (The top-level functions in the prometheus package are deprecated.)
 //
 // Pushing to the Pushgateway
 //

vendor/github.com/prometheus/client_golang/prometheus/fnv.go

@@ -1,3 +1,16 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package prometheus
 
 // Inline and byte-free variant of hash/fnv's fnv64a.

vendor/github.com/prometheus/client_golang/prometheus/gauge.go

@@ -13,6 +13,14 @@
 
 package prometheus
 
+import (
+	"math"
+	"sync/atomic"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
 // Gauge is a Metric that represents a single numerical value that can
 // arbitrarily go up and down.
 //
@@ -48,13 +56,74 @@ type Gauge interface {
 type GaugeOpts Opts
 
 // NewGauge creates a new Gauge based on the provided GaugeOpts.
+//
+// The returned implementation is optimized for a fast Set method. If you have a
+// choice for managing the value of a Gauge via Set vs. Inc/Dec/Add/Sub, pick
+// the former. For example, the Inc method of the returned Gauge is slower than
+// the Inc method of a Counter returned by NewCounter. This matches the typical
+// scenarios for Gauges and Counters, where the former tends to be Set-heavy and
+// the latter Inc-heavy.
 func NewGauge(opts GaugeOpts) Gauge {
-	return newValue(NewDesc(
+	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
 		opts.Help,
 		nil,
 		opts.ConstLabels,
-	), GaugeValue, 0)
+	)
+	result := &gauge{desc: desc, labelPairs: desc.constLabelPairs}
+	result.init(result) // Init self-collection.
+	return result
+}
+
+type gauge struct {
+	// valBits contains the bits of the represented float64 value. It has
+	// to go first in the struct to guarantee alignment for atomic
+	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+
+	selfCollector
+
+	desc       *Desc
+	labelPairs []*dto.LabelPair
+}
+
+func (g *gauge) Desc() *Desc {
+	return g.desc
+}
+
+func (g *gauge) Set(val float64) {
+	atomic.StoreUint64(&g.valBits, math.Float64bits(val))
+}
+
+func (g *gauge) SetToCurrentTime() {
+	g.Set(float64(time.Now().UnixNano()) / 1e9)
+}
+
+func (g *gauge) Inc() {
+	g.Add(1)
+}
+
+func (g *gauge) Dec() {
+	g.Add(-1)
+}
+
+func (g *gauge) Add(val float64) {
+	for {
+		oldBits := atomic.LoadUint64(&g.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
+		if atomic.CompareAndSwapUint64(&g.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (g *gauge) Sub(val float64) {
+	g.Add(val * -1)
+}
+
+func (g *gauge) Write(out *dto.Metric) error {
+	val := math.Float64frombits(atomic.LoadUint64(&g.valBits))
+	return populateMetric(GaugeValue, val, g.labelPairs, out)
 }
 
 // GaugeVec is a Collector that bundles a set of Gauges that all share the same
@@ -63,12 +132,11 @@ func NewGauge(opts GaugeOpts) Gauge {
 // (e.g. number of operations queued, partitioned by user and operation
 // type). Create instances with NewGaugeVec.
 type GaugeVec struct {
-	*MetricVec
+	*metricVec
 }
 
 // NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
+// partitioned by the given label names.
 func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -77,28 +145,62 @@ func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
 		opts.ConstLabels,
 	)
 	return &GaugeVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
-			return newValue(desc, GaugeValue, 0, lvs...)
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels) {
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
+			}
+			result := &gauge{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
+			result.init(result) // Init self-collection.
+			return result
 		}),
 	}
 }
 
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns a Gauge and not a
-// Metric so that no type conversion is required.
-func (m *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+// GetMetricWithLabelValues returns the Gauge for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Gauge is created.
+//
+// It is possible to call this method without using the returned Gauge to only
+// create the new Gauge but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Gauge for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Gauge from the GaugeVec. In that case, the
+// Gauge will still exist, but it will not be exported anymore, even if a
+// Gauge with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+func (v *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
 	if metric != nil {
 		return metric.(Gauge), err
 	}
 	return nil, err
 }
 
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns a Gauge and not a Metric so that no
-// type conversion is required.
-func (m *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
+// GetMetricWith returns the Gauge for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Gauge is created. Implications of
+// creating a Gauge without using it and keeping the Gauge for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
 	if metric != nil {
 		return metric.(Gauge), err
 	}
@@ -106,18 +208,57 @@ func (m *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
 //     myVec.WithLabelValues("404", "GET").Add(42)
-func (m *GaugeVec) WithLabelValues(lvs ...string) Gauge {
-	return m.MetricVec.WithLabelValues(lvs...).(Gauge)
+func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
+	g, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return g
 }
 
 // With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
-func (m *GaugeVec) With(labels Labels) Gauge {
-	return m.MetricVec.With(labels).(Gauge)
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *GaugeVec) With(labels Labels) Gauge {
+	g, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the GaugeVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *GaugeVec) CurryWith(labels Labels) (*GaugeVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &GaugeVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *GaugeVec) MustCurryWith(labels Labels) *GaugeVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
 }
 
 // GaugeFunc is a Gauge whose value is determined at collect time by calling a

vendor/github.com/prometheus/client_golang/prometheus/go_collector.go

@@ -1,9 +1,22 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package prometheus
 
 import (
-	"fmt"
 	"runtime"
 	"runtime/debug"
+	"sync"
 	"time"
 )
 
@@ -11,13 +24,43 @@ type goCollector struct {
 	goroutinesDesc *Desc
 	threadsDesc    *Desc
 	gcDesc         *Desc
+	goInfoDesc     *Desc
 
-	// metrics to describe and collect
-	metrics memStatsMetrics
+	// ms... are memstats related.
+	msLast          *runtime.MemStats // Previously collected memstats.
+	msLastTimestamp time.Time
+	msMtx           sync.Mutex // Protects msLast and msLastTimestamp.
+	msMetrics       memStatsMetrics
+	msRead          func(*runtime.MemStats) // For mocking in tests.
+	msMaxWait       time.Duration           // Wait time for fresh memstats.
+	msMaxAge        time.Duration           // Maximum allowed age of old memstats.
 }
 
-// NewGoCollector returns a collector which exports metrics about the current
-// go process.
+// NewGoCollector returns a collector that exports metrics about the current Go
+// process. This includes memory stats. To collect those, runtime.ReadMemStats
+// is called. This requires to “stop the world”, which usually only happens for
+// garbage collection (GC). Take the following implications into account when
+// deciding whether to use the Go collector:
+//
+// 1. The performance impact of stopping the world is the more relevant the more
+// frequently metrics are collected. However, with Go1.9 or later the
+// stop-the-world time per metrics collection is very short (~25µs) so that the
+// performance impact will only matter in rare cases. However, with older Go
+// versions, the stop-the-world duration depends on the heap size and can be
+// quite significant (~1.7 ms/GiB as per
+// https://go-review.googlesource.com/c/go/+/34937).
+//
+// 2. During an ongoing GC, nothing else can stop the world. Therefore, if the
+// metrics collection happens to coincide with GC, it will only complete after
+// GC has finished. Usually, GC is fast enough to not cause problems. However,
+// with a very large heap, GC might take multiple seconds, which is enough to
+// cause scrape timeouts in common setups. To avoid this problem, the Go
+// collector will use the memstats from a previous collection if
+// runtime.ReadMemStats takes more than 1s. However, if there are no previously
+// collected memstats, or their collection is more than 5m ago, the collection
+// will block until runtime.ReadMemStats succeeds. (The problem might be solved
+// in Go1.13, see https://github.com/golang/go/issues/19812 for the related Go
+// issue.)
 func NewGoCollector() Collector {
 	return &goCollector{
 		goroutinesDesc: NewDesc(
@@ -26,13 +69,21 @@ func NewGoCollector() Collector {
 			nil, nil),
 		threadsDesc: NewDesc(
 			"go_threads",
-			"Number of OS threads created",
+			"Number of OS threads created.",
 			nil, nil),
 		gcDesc: NewDesc(
 			"go_gc_duration_seconds",
 			"A summary of the GC invocation durations.",
 			nil, nil),
-		metrics: memStatsMetrics{
+		goInfoDesc: NewDesc(
+			"go_info",
+			"Information about the Go environment.",
+			nil, Labels{"version": runtime.Version()}),
+		msLast:    &runtime.MemStats{},
+		msRead:    runtime.ReadMemStats,
+		msMaxWait: time.Second,
+		msMaxAge:  5 * time.Minute,
+		msMetrics: memStatsMetrics{
 			{
 				desc: NewDesc(
 					memstatNamespace("alloc_bytes"),
@@ -231,7 +282,7 @@ func NewGoCollector() Collector {
 }
 
 func memstatNamespace(s string) string {
-	return fmt.Sprintf("go_memstats_%s", s)
+	return "go_memstats_" + s
 }
 
 // Describe returns all descriptions of the collector.
@@ -239,13 +290,28 @@ func (c *goCollector) Describe(ch chan<- *Desc) {
 	ch <- c.goroutinesDesc
 	ch <- c.threadsDesc
 	ch <- c.gcDesc
-	for _, i := range c.metrics {
+	ch <- c.goInfoDesc
+	for _, i := range c.msMetrics {
 		ch <- i.desc
 	}
 }
 
 // Collect returns the current state of all metrics of the collector.
 func (c *goCollector) Collect(ch chan<- Metric) {
+	var (
+		ms   = &runtime.MemStats{}
+		done = make(chan struct{})
+	)
+	// Start reading memstats first as it might take a while.
+	go func() {
+		c.msRead(ms)
+		c.msMtx.Lock()
+		c.msLast = ms
+		c.msLastTimestamp = time.Now()
+		c.msMtx.Unlock()
+		close(done)
+	}()
+
 	ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
 	n, _ := runtime.ThreadCreateProfile(nil)
 	ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, float64(n))
@@ -259,11 +325,35 @@ func (c *goCollector) Collect(ch chan<- Metric) {
 		quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
 	}
 	quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
-	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), float64(stats.PauseTotal.Seconds()), quantiles)
+	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), stats.PauseTotal.Seconds(), quantiles)
 
-	ms := &runtime.MemStats{}
-	runtime.ReadMemStats(ms)
-	for _, i := range c.metrics {
+	ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
+
+	timer := time.NewTimer(c.msMaxWait)
+	select {
+	case <-done: // Our own ReadMemStats succeeded in time. Use it.
+		timer.Stop() // Important for high collection frequencies to not pile up timers.
+		c.msCollect(ch, ms)
+		return
+	case <-timer.C: // Time out, use last memstats if possible. Continue below.
+	}
+	c.msMtx.Lock()
+	if time.Since(c.msLastTimestamp) < c.msMaxAge {
+		// Last memstats are recent enough. Collect from them under the lock.
+		c.msCollect(ch, c.msLast)
+		c.msMtx.Unlock()
+		return
+	}
+	// If we are here, the last memstats are too old or don't exist. We have
+	// to wait until our own ReadMemStats finally completes. For that to
+	// happen, we have to release the lock.
+	c.msMtx.Unlock()
+	<-done
+	c.msCollect(ch, ms)
+}
+
+func (c *goCollector) msCollect(ch chan<- Metric, ms *runtime.MemStats) {
+	for _, i := range c.msMetrics {
 		ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
 	}
 }
@@ -274,3 +364,33 @@ type memStatsMetrics []struct {
 	eval    func(*runtime.MemStats) float64
 	valType ValueType
 }
+
+// NewBuildInfoCollector returns a collector collecting a single metric
+// "go_build_info" with the constant value 1 and three labels "path", "version",
+// and "checksum". Their label values contain the main module path, version, and
+// checksum, respectively. The labels will only have meaningful values if the
+// binary is built with Go module support and from source code retrieved from
+// the source repository (rather than the local file system). This is usually
+// accomplished by building from outside of GOPATH, specifying the full address
+// of the main package, e.g. "GO111MODULE=on go run
+// github.com/prometheus/client_golang/examples/random". If built without Go
+// module support, all label values will be "unknown". If built with Go module
+// support but using the source code from the local file system, the "path" will
+// be set appropriately, but "checksum" will be empty and "version" will be
+// "(devel)".
+//
+// This collector uses only the build information for the main module. See
+// https://github.com/povilasv/prommod for an example of a collector for the
+// module dependencies.
+func NewBuildInfoCollector() Collector {
+	path, version, sum := readBuildInfo()
+	c := &selfCollector{MustNewConstMetric(
+		NewDesc(
+			"go_build_info",
+			"Build information about the main Go module.",
+			nil, Labels{"path": path, "version": version, "checksum": sum},
+		),
+		GaugeValue, 1)}
+	c.init(c.self)
+	return c
+}

vendor/github.com/prometheus/client_golang/prometheus/histogram.go

@@ -16,7 +16,9 @@ package prometheus
 import (
 	"fmt"
 	"math"
+	"runtime"
 	"sort"
+	"sync"
 	"sync/atomic"
 
 	"github.com/golang/protobuf/proto"
@@ -108,8 +110,9 @@ func ExponentialBuckets(start, factor float64, count int) []float64 {
 }
 
 // HistogramOpts bundles the options for creating a Histogram metric. It is
-// mandatory to set Name and Help to a non-empty string. All other fields are
-// optional and can safely be left at their zero value.
+// mandatory to set Name to a non-empty string. All other fields are optional
+// and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
 type HistogramOpts struct {
 	// Namespace, Subsystem, and Name are components of the fully-qualified
 	// name of the Histogram (created by joining these components with
@@ -120,29 +123,22 @@ type HistogramOpts struct {
 	Subsystem string
 	Name      string
 
-	// Help provides information about this Histogram. Mandatory!
+	// Help provides information about this Histogram.
 	//
 	// Metrics with the same fully-qualified name must have the same Help
 	// string.
 	Help string
 
-	// ConstLabels are used to attach fixed labels to this
-	// Histogram. Histograms with the same fully-qualified name must have the
-	// same label names in their ConstLabels.
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
 	//
-	// Note that in most cases, labels have a value that varies during the
-	// lifetime of a process. Those labels are usually managed with a
-	// HistogramVec. ConstLabels serve only special purposes. One is for the
-	// special case where the value of a label does not change during the
-	// lifetime of a process, e.g. if the revision of the running binary is
-	// put into a label. Another, more advanced purpose is if more than one
-	// Collector needs to collect Histograms with the same fully-qualified
-	// name. In that case, those Summaries must differ in the values of
-	// their ConstLabels. See the Collector examples.
-	//
-	// If the value of a label never changes (not even between binaries),
-	// that label most likely should not be a label at all (but part of the
-	// metric name).
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
 	ConstLabels Labels
 
 	// Buckets defines the buckets into which observations are counted. Each
@@ -169,7 +165,7 @@ func NewHistogram(opts HistogramOpts) Histogram {
 
 func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram {
 	if len(desc.variableLabels) != len(labelValues) {
-		panic(errInconsistentCardinality)
+		panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, labelValues))
 	}
 
 	for _, n := range desc.variableLabels {
@@ -191,6 +187,7 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 		desc:        desc,
 		upperBounds: opts.Buckets,
 		labelPairs:  makeLabelPairs(desc, labelValues),
+		counts:      [2]*histogramCounts{&histogramCounts{}, &histogramCounts{}},
 	}
 	for i, upperBound := range h.upperBounds {
 		if i < len(h.upperBounds)-1 {
@@ -207,30 +204,56 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 			}
 		}
 	}
-	// Finally we know the final length of h.upperBounds and can make counts.
-	h.counts = make([]uint64, len(h.upperBounds))
+	// Finally we know the final length of h.upperBounds and can make buckets
+	// for both counts:
+	h.counts[0].buckets = make([]uint64, len(h.upperBounds))
+	h.counts[1].buckets = make([]uint64, len(h.upperBounds))
 
 	h.init(h) // Init self-collection.
 	return h
 }
 
-type histogram struct {
+type histogramCounts struct {
 	// sumBits contains the bits of the float64 representing the sum of all
 	// observations. sumBits and count have to go first in the struct to
 	// guarantee alignment for atomic operations.
 	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
 	sumBits uint64
 	count   uint64
+	buckets []uint64
+}
+
+type histogram struct {
+	// countAndHotIdx enables lock-free writes with use of atomic updates.
+	// The most significant bit is the hot index [0 or 1] of the count field
+	// below. Observe calls update the hot one. All remaining bits count the
+	// number of Observe calls. Observe starts by incrementing this counter,
+	// and finish by incrementing the count field in the respective
+	// histogramCounts, as a marker for completion.
+	//
+	// Calls of the Write method (which are non-mutating reads from the
+	// perspective of the histogram) swap the hot–cold under the writeMtx
+	// lock. A cooldown is awaited (while locked) by comparing the number of
+	// observations with the initiation count. Once they match, then the
+	// last observation on the now cool one has completed. All cool fields must
+	// be merged into the new hot before releasing writeMtx.
+	//
+	// Fields with atomic access first! See alignment constraint:
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	countAndHotIdx uint64
 
 	selfCollector
-	// Note that there is no mutex required.
+	desc     *Desc
+	writeMtx sync.Mutex // Only used in the Write method.
 
-	desc *Desc
+	// Two counts, one is "hot" for lock-free observations, the other is
+	// "cold" for writing out a dto.Metric. It has to be an array of
+	// pointers to guarantee 64bit alignment of the histogramCounts, see
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG.
+	counts [2]*histogramCounts
 
 	upperBounds []float64
-	counts      []uint64
-
-	labelPairs []*dto.LabelPair
+	labelPairs  []*dto.LabelPair
 }
 
 func (h *histogram) Desc() *Desc {
@@ -248,36 +271,84 @@ func (h *histogram) Observe(v float64) {
 	// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
 	// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
 	i := sort.SearchFloat64s(h.upperBounds, v)
-	if i < len(h.counts) {
-		atomic.AddUint64(&h.counts[i], 1)
+
+	// We increment h.countAndHotIdx so that the counter in the lower
+	// 63 bits gets incremented. At the same time, we get the new value
+	// back, which we can use to find the currently-hot counts.
+	n := atomic.AddUint64(&h.countAndHotIdx, 1)
+	hotCounts := h.counts[n>>63]
+
+	if i < len(h.upperBounds) {
+		atomic.AddUint64(&hotCounts.buckets[i], 1)
 	}
-	atomic.AddUint64(&h.count, 1)
 	for {
-		oldBits := atomic.LoadUint64(&h.sumBits)
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
 		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
-		if atomic.CompareAndSwapUint64(&h.sumBits, oldBits, newBits) {
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
 			break
 		}
 	}
+	// Increment count last as we take it as a signal that the observation
+	// is complete.
+	atomic.AddUint64(&hotCounts.count, 1)
 }
 
 func (h *histogram) Write(out *dto.Metric) error {
-	his := &dto.Histogram{}
-	buckets := make([]*dto.Bucket, len(h.upperBounds))
+	// For simplicity, we protect this whole method by a mutex. It is not in
+	// the hot path, i.e. Observe is called much more often than Write. The
+	// complication of making Write lock-free isn't worth it, if possible at
+	// all.
+	h.writeMtx.Lock()
+	defer h.writeMtx.Unlock()
 
-	his.SampleSum = proto.Float64(math.Float64frombits(atomic.LoadUint64(&h.sumBits)))
-	his.SampleCount = proto.Uint64(atomic.LoadUint64(&h.count))
-	var count uint64
+	// Adding 1<<63 switches the hot index (from 0 to 1 or from 1 to 0)
+	// without touching the count bits. See the struct comments for a full
+	// description of the algorithm.
+	n := atomic.AddUint64(&h.countAndHotIdx, 1<<63)
+	// count is contained unchanged in the lower 63 bits.
+	count := n & ((1 << 63) - 1)
+	// The most significant bit tells us which counts is hot. The complement
+	// is thus the cold one.
+	hotCounts := h.counts[n>>63]
+	coldCounts := h.counts[(^n)>>63]
+
+	// Await cooldown.
+	for count != atomic.LoadUint64(&coldCounts.count) {
+		runtime.Gosched() // Let observations get work done.
+	}
+
+	his := &dto.Histogram{
+		Bucket:      make([]*dto.Bucket, len(h.upperBounds)),
+		SampleCount: proto.Uint64(count),
+		SampleSum:   proto.Float64(math.Float64frombits(atomic.LoadUint64(&coldCounts.sumBits))),
+	}
+	var cumCount uint64
 	for i, upperBound := range h.upperBounds {
-		count += atomic.LoadUint64(&h.counts[i])
-		buckets[i] = &dto.Bucket{
-			CumulativeCount: proto.Uint64(count),
+		cumCount += atomic.LoadUint64(&coldCounts.buckets[i])
+		his.Bucket[i] = &dto.Bucket{
+			CumulativeCount: proto.Uint64(cumCount),
 			UpperBound:      proto.Float64(upperBound),
 		}
 	}
-	his.Bucket = buckets
+
 	out.Histogram = his
 	out.Label = h.labelPairs
+
+	// Finally add all the cold counts to the new hot counts and reset the cold counts.
+	atomic.AddUint64(&hotCounts.count, count)
+	atomic.StoreUint64(&coldCounts.count, 0)
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + his.GetSampleSum())
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			atomic.StoreUint64(&coldCounts.sumBits, 0)
+			break
+		}
+	}
+	for i := range h.upperBounds {
+		atomic.AddUint64(&hotCounts.buckets[i], atomic.LoadUint64(&coldCounts.buckets[i]))
+		atomic.StoreUint64(&coldCounts.buckets[i], 0)
+	}
 	return nil
 }
 
@@ -287,12 +358,11 @@ func (h *histogram) Write(out *dto.Metric) error {
 // (e.g. HTTP request latencies, partitioned by status code and method). Create
 // instances with NewHistogramVec.
 type HistogramVec struct {
-	*MetricVec
+	*metricVec
 }
 
 // NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
+// partitioned by the given label names.
 func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
@@ -301,47 +371,116 @@ func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
 		opts.ConstLabels,
 	)
 	return &HistogramVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
 			return newHistogram(desc, opts, lvs...)
 		}),
 	}
 }
 
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns a Histogram and not a
-// Metric so that no type conversion is required.
-func (m *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Histogram, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+// GetMetricWithLabelValues returns the Histogram for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Histogram is created.
+//
+// It is possible to call this method without using the returned Histogram to only
+// create the new Histogram but leave it at its starting value, a Histogram without
+// any observations.
+//
+// Keeping the Histogram for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Histogram from the HistogramVec. In that case, the
+// Histogram will still exist, but it will not be exported anymore, even if a
+// Histogram with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
 	if metric != nil {
-		return metric.(Histogram), err
+		return metric.(Observer), err
 	}
 	return nil, err
 }
 
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns a Histogram and not a Metric so that no
-// type conversion is required.
-func (m *HistogramVec) GetMetricWith(labels Labels) (Histogram, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
+// GetMetricWith returns the Histogram for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Histogram is created. Implications of
+// creating a Histogram without using it and keeping the Histogram for later use
+// are the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *HistogramVec) GetMetricWith(labels Labels) (Observer, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
 	if metric != nil {
-		return metric.(Histogram), err
+		return metric.(Observer), err
 	}
 	return nil, err
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
 //     myVec.WithLabelValues("404", "GET").Observe(42.21)
-func (m *HistogramVec) WithLabelValues(lvs ...string) Histogram {
-	return m.MetricVec.WithLabelValues(lvs...).(Histogram)
+func (v *HistogramVec) WithLabelValues(lvs ...string) Observer {
+	h, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return h
 }
 
-// With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21)
-func (m *HistogramVec) With(labels Labels) Histogram {
-	return m.MetricVec.With(labels).(Histogram)
+// With works as GetMetricWith but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (v *HistogramVec) With(labels Labels) Observer {
+	h, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return h
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the HistogramVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *HistogramVec) CurryWith(labels Labels) (ObserverVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &HistogramVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *HistogramVec) MustCurryWith(labels Labels) ObserverVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
 }
 
 type constHistogram struct {
@@ -393,7 +532,7 @@ func (h *constHistogram) Write(out *dto.Metric) error {
 // bucket.
 //
 // NewConstHistogram returns an error if the length of labelValues is not
-// consistent with the variable labels in Desc.
+// consistent with the variable labels in Desc or if Desc is invalid.
 func NewConstHistogram(
 	desc *Desc,
 	count uint64,
@@ -401,8 +540,11 @@ func NewConstHistogram(
 	buckets map[float64]uint64,
 	labelValues ...string,
 ) (Metric, error) {
-	if len(desc.variableLabels) != len(labelValues) {
-		return nil, errInconsistentCardinality
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
+		return nil, err
 	}
 	return &constHistogram{
 		desc:       desc,

vendor/github.com/prometheus/client_golang/prometheus/http.go

@@ -1,526 +0,0 @@
-// Copyright 2014 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package prometheus
-
-import (
-	"bufio"
-	"bytes"
-	"compress/gzip"
-	"fmt"
-	"io"
-	"net"
-	"net/http"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-
-	"github.com/prometheus/common/expfmt"
-)
-
-// TODO(beorn7): Remove this whole file. It is a partial mirror of
-// promhttp/http.go (to avoid circular import chains) where everything HTTP
-// related should live. The functions here are just for avoiding
-// breakage. Everything is deprecated.
-
-const (
-	contentTypeHeader     = "Content-Type"
-	contentLengthHeader   = "Content-Length"
-	contentEncodingHeader = "Content-Encoding"
-	acceptEncodingHeader  = "Accept-Encoding"
-)
-
-var bufPool sync.Pool
-
-func getBuf() *bytes.Buffer {
-	buf := bufPool.Get()
-	if buf == nil {
-		return &bytes.Buffer{}
-	}
-	return buf.(*bytes.Buffer)
-}
-
-func giveBuf(buf *bytes.Buffer) {
-	buf.Reset()
-	bufPool.Put(buf)
-}
-
-// Handler returns an HTTP handler for the DefaultGatherer. It is
-// already instrumented with InstrumentHandler (using "prometheus" as handler
-// name).
-//
-// Deprecated: Please note the issues described in the doc comment of
-// InstrumentHandler. You might want to consider using promhttp.Handler instead
-// (which is not instrumented).
-func Handler() http.Handler {
-	return InstrumentHandler("prometheus", UninstrumentedHandler())
-}
-
-// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer.
-//
-// Deprecated: Use promhttp.Handler instead. See there for further documentation.
-func UninstrumentedHandler() http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-		mfs, err := DefaultGatherer.Gather()
-		if err != nil {
-			http.Error(w, "An error has occurred during metrics collection:\n\n"+err.Error(), http.StatusInternalServerError)
-			return
-		}
-
-		contentType := expfmt.Negotiate(req.Header)
-		buf := getBuf()
-		defer giveBuf(buf)
-		writer, encoding := decorateWriter(req, buf)
-		enc := expfmt.NewEncoder(writer, contentType)
-		var lastErr error
-		for _, mf := range mfs {
-			if err := enc.Encode(mf); err != nil {
-				lastErr = err
-				http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
-				return
-			}
-		}
-		if closer, ok := writer.(io.Closer); ok {
-			closer.Close()
-		}
-		if lastErr != nil && buf.Len() == 0 {
-			http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		header := w.Header()
-		header.Set(contentTypeHeader, string(contentType))
-		header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
-		if encoding != "" {
-			header.Set(contentEncodingHeader, encoding)
-		}
-		w.Write(buf.Bytes())
-	})
-}
-
-// decorateWriter wraps a writer to handle gzip compression if requested.  It
-// returns the decorated writer and the appropriate "Content-Encoding" header
-// (which is empty if no compression is enabled).
-func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) {
-	header := request.Header.Get(acceptEncodingHeader)
-	parts := strings.Split(header, ",")
-	for _, part := range parts {
-		part := strings.TrimSpace(part)
-		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
-			return gzip.NewWriter(writer), "gzip"
-		}
-	}
-	return writer, ""
-}
-
-var instLabels = []string{"method", "code"}
-
-type nower interface {
-	Now() time.Time
-}
-
-type nowFunc func() time.Time
-
-func (n nowFunc) Now() time.Time {
-	return n()
-}
-
-var now nower = nowFunc(func() time.Time {
-	return time.Now()
-})
-
-func nowSeries(t ...time.Time) nower {
-	return nowFunc(func() time.Time {
-		defer func() {
-			t = t[1:]
-		}()
-
-		return t[0]
-	})
-}
-
-// InstrumentHandler wraps the given HTTP handler for instrumentation. It
-// registers four metric collectors (if not already done) and reports HTTP
-// metrics to the (newly or already) registered collectors: http_requests_total
-// (CounterVec), http_request_duration_microseconds (Summary),
-// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each
-// has a constant label named "handler" with the provided handlerName as
-// value. http_requests_total is a metric vector partitioned by HTTP method
-// (label name "method") and HTTP status code (label name "code").
-//
-// Deprecated: InstrumentHandler has several issues:
-//
-// - It uses Summaries rather than Histograms. Summaries are not useful if
-// aggregation across multiple instances is required.
-//
-// - It uses microseconds as unit, which is deprecated and should be replaced by
-// seconds.
-//
-// - The size of the request is calculated in a separate goroutine. Since this
-// calculator requires access to the request header, it creates a race with
-// any writes to the header performed during request handling.
-// httputil.ReverseProxy is a prominent example for a handler
-// performing such writes.
-//
-// - It has additional issues with HTTP/2, cf.
-// https://github.com/prometheus/client_golang/issues/272.
-//
-// Upcoming versions of this package will provide ways of instrumenting HTTP
-// handlers that are more flexible and have fewer issues. Please prefer direct
-// instrumentation in the meantime.
-func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
-	return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
-}
-
-// InstrumentHandlerFunc wraps the given function for instrumentation. It
-// otherwise works in the same way as InstrumentHandler (and shares the same
-// issues).
-//
-// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
-// InstrumentHandler is.
-func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
-	return InstrumentHandlerFuncWithOpts(
-		SummaryOpts{
-			Subsystem:   "http",
-			ConstLabels: Labels{"handler": handlerName},
-			Objectives:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
-		},
-		handlerFunc,
-	)
-}
-
-// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same
-// issues) but provides more flexibility (at the cost of a more complex call
-// syntax). As InstrumentHandler, this function registers four metric
-// collectors, but it uses the provided SummaryOpts to create them. However, the
-// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced
-// by "requests_total", "request_duration_microseconds", "request_size_bytes",
-// and "response_size_bytes", respectively. "Help" is replaced by an appropriate
-// help string. The names of the variable labels of the http_requests_total
-// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
-//
-// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the
-// behavior of InstrumentHandler:
-//
-//     prometheus.InstrumentHandlerWithOpts(
-//         prometheus.SummaryOpts{
-//              Subsystem:   "http",
-//              ConstLabels: prometheus.Labels{"handler": handlerName},
-//         },
-//         handler,
-//     )
-//
-// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it
-// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
-// and all its fields are set to the equally named fields in the provided
-// SummaryOpts.
-//
-// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
-// InstrumentHandler is.
-func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
-	return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
-}
-
-// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares
-// the same issues) but provides more flexibility (at the cost of a more complex
-// call syntax). See InstrumentHandlerWithOpts for details how the provided
-// SummaryOpts are used.
-//
-// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
-// as InstrumentHandler is.
-func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
-	reqCnt := NewCounterVec(
-		CounterOpts{
-			Namespace:   opts.Namespace,
-			Subsystem:   opts.Subsystem,
-			Name:        "requests_total",
-			Help:        "Total number of HTTP requests made.",
-			ConstLabels: opts.ConstLabels,
-		},
-		instLabels,
-	)
-	if err := Register(reqCnt); err != nil {
-		if are, ok := err.(AlreadyRegisteredError); ok {
-			reqCnt = are.ExistingCollector.(*CounterVec)
-		} else {
-			panic(err)
-		}
-	}
-
-	opts.Name = "request_duration_microseconds"
-	opts.Help = "The HTTP request latencies in microseconds."
-	reqDur := NewSummary(opts)
-	if err := Register(reqDur); err != nil {
-		if are, ok := err.(AlreadyRegisteredError); ok {
-			reqDur = are.ExistingCollector.(Summary)
-		} else {
-			panic(err)
-		}
-	}
-
-	opts.Name = "request_size_bytes"
-	opts.Help = "The HTTP request sizes in bytes."
-	reqSz := NewSummary(opts)
-	if err := Register(reqSz); err != nil {
-		if are, ok := err.(AlreadyRegisteredError); ok {
-			reqSz = are.ExistingCollector.(Summary)
-		} else {
-			panic(err)
-		}
-	}
-
-	opts.Name = "response_size_bytes"
-	opts.Help = "The HTTP response sizes in bytes."
-	resSz := NewSummary(opts)
-	if err := Register(resSz); err != nil {
-		if are, ok := err.(AlreadyRegisteredError); ok {
-			resSz = are.ExistingCollector.(Summary)
-		} else {
-			panic(err)
-		}
-	}
-
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		now := time.Now()
-
-		delegate := &responseWriterDelegator{ResponseWriter: w}
-		out := computeApproximateRequestSize(r)
-
-		_, cn := w.(http.CloseNotifier)
-		_, fl := w.(http.Flusher)
-		_, hj := w.(http.Hijacker)
-		_, rf := w.(io.ReaderFrom)
-		var rw http.ResponseWriter
-		if cn && fl && hj && rf {
-			rw = &fancyResponseWriterDelegator{delegate}
-		} else {
-			rw = delegate
-		}
-		handlerFunc(rw, r)
-
-		elapsed := float64(time.Since(now)) / float64(time.Microsecond)
-
-		method := sanitizeMethod(r.Method)
-		code := sanitizeCode(delegate.status)
-		reqCnt.WithLabelValues(method, code).Inc()
-		reqDur.Observe(elapsed)
-		resSz.Observe(float64(delegate.written))
-		reqSz.Observe(float64(<-out))
-	})
-}
-
-func computeApproximateRequestSize(r *http.Request) <-chan int {
-	// Get URL length in current go routine for avoiding a race condition.
-	// HandlerFunc that runs in parallel may modify the URL.
-	s := 0
-	if r.URL != nil {
-		s += len(r.URL.String())
-	}
-
-	out := make(chan int, 1)
-
-	go func() {
-		s += len(r.Method)
-		s += len(r.Proto)
-		for name, values := range r.Header {
-			s += len(name)
-			for _, value := range values {
-				s += len(value)
-			}
-		}
-		s += len(r.Host)
-
-		// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
-
-		if r.ContentLength != -1 {
-			s += int(r.ContentLength)
-		}
-		out <- s
-		close(out)
-	}()
-
-	return out
-}
-
-type responseWriterDelegator struct {
-	http.ResponseWriter
-
-	handler, method string
-	status          int
-	written         int64
-	wroteHeader     bool
-}
-
-func (r *responseWriterDelegator) WriteHeader(code int) {
-	r.status = code
-	r.wroteHeader = true
-	r.ResponseWriter.WriteHeader(code)
-}
-
-func (r *responseWriterDelegator) Write(b []byte) (int, error) {
-	if !r.wroteHeader {
-		r.WriteHeader(http.StatusOK)
-	}
-	n, err := r.ResponseWriter.Write(b)
-	r.written += int64(n)
-	return n, err
-}
-
-type fancyResponseWriterDelegator struct {
-	*responseWriterDelegator
-}
-
-func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
-	return f.ResponseWriter.(http.CloseNotifier).CloseNotify()
-}
-
-func (f *fancyResponseWriterDelegator) Flush() {
-	f.ResponseWriter.(http.Flusher).Flush()
-}
-
-func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
-	return f.ResponseWriter.(http.Hijacker).Hijack()
-}
-
-func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) {
-	if !f.wroteHeader {
-		f.WriteHeader(http.StatusOK)
-	}
-	n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r)
-	f.written += n
-	return n, err
-}
-
-func sanitizeMethod(m string) string {
-	switch m {
-	case "GET", "get":
-		return "get"
-	case "PUT", "put":
-		return "put"
-	case "HEAD", "head":
-		return "head"
-	case "POST", "post":
-		return "post"
-	case "DELETE", "delete":
-		return "delete"
-	case "CONNECT", "connect":
-		return "connect"
-	case "OPTIONS", "options":
-		return "options"
-	case "NOTIFY", "notify":
-		return "notify"
-	default:
-		return strings.ToLower(m)
-	}
-}
-
-func sanitizeCode(s int) string {
-	switch s {
-	case 100:
-		return "100"
-	case 101:
-		return "101"
-
-	case 200:
-		return "200"
-	case 201:
-		return "201"
-	case 202:
-		return "202"
-	case 203:
-		return "203"
-	case 204:
-		return "204"
-	case 205:
-		return "205"
-	case 206:
-		return "206"
-
-	case 300:
-		return "300"
-	case 301:
-		return "301"
-	case 302:
-		return "302"
-	case 304:
-		return "304"
-	case 305:
-		return "305"
-	case 307:
-		return "307"
-
-	case 400:
-		return "400"
-	case 401:
-		return "401"
-	case 402:
-		return "402"
-	case 403:
-		return "403"
-	case 404:
-		return "404"
-	case 405:
-		return "405"
-	case 406:
-		return "406"
-	case 407:
-		return "407"
-	case 408:
-		return "408"
-	case 409:
-		return "409"
-	case 410:
-		return "410"
-	case 411:
-		return "411"
-	case 412:
-		return "412"
-	case 413:
-		return "413"
-	case 414:
-		return "414"
-	case 415:
-		return "415"
-	case 416:
-		return "416"
-	case 417:
-		return "417"
-	case 418:
-		return "418"
-
-	case 500:
-		return "500"
-	case 501:
-		return "501"
-	case 502:
-		return "502"
-	case 503:
-		return "503"
-	case 504:
-		return "504"
-	case 505:
-		return "505"
-
-	case 428:
-		return "428"
-	case 429:
-		return "429"
-	case 431:
-		return "431"
-	case 511:
-		return "511"
-
-	default:
-		return strconv.Itoa(s)
-	}
-}

vendor/github.com/prometheus/client_golang/prometheus/internal/metric.go

@@ -0,0 +1,85 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"sort"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// metricSorter is a sortable slice of *dto.Metric.
+type metricSorter []*dto.Metric
+
+func (s metricSorter) Len() int {
+	return len(s)
+}
+
+func (s metricSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s metricSorter) Less(i, j int) bool {
+	if len(s[i].Label) != len(s[j].Label) {
+		// This should not happen. The metrics are
+		// inconsistent. However, we have to deal with the fact, as
+		// people might use custom collectors or metric family injection
+		// to create inconsistent metrics. So let's simply compare the
+		// number of labels in this case. That will still yield
+		// reproducible sorting.
+		return len(s[i].Label) < len(s[j].Label)
+	}
+	for n, lp := range s[i].Label {
+		vi := lp.GetValue()
+		vj := s[j].Label[n].GetValue()
+		if vi != vj {
+			return vi < vj
+		}
+	}
+
+	// We should never arrive here. Multiple metrics with the same
+	// label set in the same scrape will lead to undefined ingestion
+	// behavior. However, as above, we have to provide stable sorting
+	// here, even for inconsistent metrics. So sort equal metrics
+	// by their timestamp, with missing timestamps (implying "now")
+	// coming last.
+	if s[i].TimestampMs == nil {
+		return false
+	}
+	if s[j].TimestampMs == nil {
+		return true
+	}
+	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
+}
+
+// NormalizeMetricFamilies returns a MetricFamily slice with empty
+// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
+// the slice, with the contained Metrics sorted within each MetricFamily.
+func NormalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
+	for _, mf := range metricFamiliesByName {
+		sort.Sort(metricSorter(mf.Metric))
+	}
+	names := make([]string, 0, len(metricFamiliesByName))
+	for name, mf := range metricFamiliesByName {
+		if len(mf.Metric) > 0 {
+			names = append(names, name)
+		}
+	}
+	sort.Strings(names)
+	result := make([]*dto.MetricFamily, 0, len(names))
+	for _, name := range names {
+		result = append(result, metricFamiliesByName[name])
+	}
+	return result
+}

vendor/github.com/prometheus/client_golang/prometheus/labels.go

@@ -0,0 +1,87 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/prometheus/common/model"
+)
+
+// Labels represents a collection of label name -> value mappings. This type is
+// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
+// metric vector Collectors, e.g.:
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+//
+// The other use-case is the specification of constant label pairs in Opts or to
+// create a Desc.
+type Labels map[string]string
+
+// reservedLabelPrefix is a prefix which is not legal in user-supplied
+// label names.
+const reservedLabelPrefix = "__"
+
+var errInconsistentCardinality = errors.New("inconsistent label cardinality")
+
+func makeInconsistentCardinalityError(fqName string, labels, labelValues []string) error {
+	return fmt.Errorf(
+		"%s: %q has %d variable labels named %q but %d values %q were provided",
+		errInconsistentCardinality, fqName,
+		len(labels), labels,
+		len(labelValues), labelValues,
+	)
+}
+
+func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
+	if len(labels) != expectedNumberOfValues {
+		return fmt.Errorf(
+			"%s: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(labels), labels,
+		)
+	}
+
+	for name, val := range labels {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label %s: value %q is not valid UTF-8", name, val)
+		}
+	}
+
+	return nil
+}
+
+func validateLabelValues(vals []string, expectedNumberOfValues int) error {
+	if len(vals) != expectedNumberOfValues {
+		return fmt.Errorf(
+			"%s: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(vals), vals,
+		)
+	}
+
+	for _, val := range vals {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label value %q is not valid UTF-8", val)
+		}
+	}
+
+	return nil
+}
+
+func checkLabelName(l string) bool {
+	return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
+}

vendor/github.com/prometheus/client_golang/prometheus/metric.go

@@ -15,6 +15,9 @@ package prometheus
 
 import (
 	"strings"
+	"time"
+
+	"github.com/golang/protobuf/proto"
 
 	dto "github.com/prometheus/client_model/go"
 )
@@ -43,9 +46,8 @@ type Metric interface {
 	// While populating dto.Metric, it is the responsibility of the
 	// implementation to ensure validity of the Metric protobuf (like valid
 	// UTF-8 strings or syntactically valid metric and label names). It is
-	// recommended to sort labels lexicographically. (Implementers may find
-	// LabelPairSorter useful for that.) Callers of Write should still make
-	// sure of sorting if they depend on it.
+	// recommended to sort labels lexicographically. Callers of Write should
+	// still make sure of sorting if they depend on it.
 	Write(*dto.Metric) error
 	// TODO(beorn7): The original rationale of passing in a pre-allocated
 	// dto.Metric protobuf to save allocations has disappeared. The
@@ -57,8 +59,9 @@ type Metric interface {
 // implementation XXX has its own XXXOpts type, but in most cases, it is just be
 // an alias of this type (which might change when the requirement arises.)
 //
-// It is mandatory to set Name and Help to a non-empty string. All other fields
-// are optional and can safely be left at their zero value.
+// It is mandatory to set Name to a non-empty string. All other fields are
+// optional and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
 type Opts struct {
 	// Namespace, Subsystem, and Name are components of the fully-qualified
 	// name of the Metric (created by joining these components with
@@ -69,7 +72,7 @@ type Opts struct {
 	Subsystem string
 	Name      string
 
-	// Help provides information about this metric. Mandatory!
+	// Help provides information about this metric.
 	//
 	// Metrics with the same fully-qualified name must have the same Help
 	// string.
@@ -79,20 +82,12 @@ type Opts struct {
 	// with the same fully-qualified name must have the same label names in
 	// their ConstLabels.
 	//
-	// Note that in most cases, labels have a value that varies during the
-	// lifetime of a process. Those labels are usually managed with a metric
-	// vector collector (like CounterVec, GaugeVec, UntypedVec). ConstLabels
-	// serve only special purposes. One is for the special case where the
-	// value of a label does not change during the lifetime of a process,
-	// e.g. if the revision of the running binary is put into a
-	// label. Another, more advanced purpose is if more than one Collector
-	// needs to collect Metrics with the same fully-qualified name. In that
-	// case, those Metrics must differ in the values of their
-	// ConstLabels. See the Collector examples.
-	//
-	// If the value of a label never changes (not even between binaries),
-	// that label most likely should not be a label at all (but part of the
-	// metric name).
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
 	ConstLabels Labels
 }
 
@@ -118,37 +113,22 @@ func BuildFQName(namespace, subsystem, name string) string {
 	return name
 }
 
-// LabelPairSorter implements sort.Interface. It is used to sort a slice of
-// dto.LabelPair pointers. This is useful for implementing the Write method of
-// custom metrics.
-type LabelPairSorter []*dto.LabelPair
+// labelPairSorter implements sort.Interface. It is used to sort a slice of
+// dto.LabelPair pointers.
+type labelPairSorter []*dto.LabelPair
 
-func (s LabelPairSorter) Len() int {
+func (s labelPairSorter) Len() int {
 	return len(s)
 }
 
-func (s LabelPairSorter) Swap(i, j int) {
+func (s labelPairSorter) Swap(i, j int) {
 	s[i], s[j] = s[j], s[i]
 }
 
-func (s LabelPairSorter) Less(i, j int) bool {
+func (s labelPairSorter) Less(i, j int) bool {
 	return s[i].GetName() < s[j].GetName()
 }
 
-type hashSorter []uint64
-
-func (s hashSorter) Len() int {
-	return len(s)
-}
-
-func (s hashSorter) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
-}
-
-func (s hashSorter) Less(i, j int) bool {
-	return s[i] < s[j]
-}
-
 type invalidMetric struct {
 	desc *Desc
 	err  error
@@ -164,3 +144,31 @@ func NewInvalidMetric(desc *Desc, err error) Metric {
 func (m *invalidMetric) Desc() *Desc { return m.desc }
 
 func (m *invalidMetric) Write(*dto.Metric) error { return m.err }
+
+type timestampedMetric struct {
+	Metric
+	t time.Time
+}
+
+func (m timestampedMetric) Write(pb *dto.Metric) error {
+	e := m.Metric.Write(pb)
+	pb.TimestampMs = proto.Int64(m.t.Unix()*1000 + int64(m.t.Nanosecond()/1000000))
+	return e
+}
+
+// NewMetricWithTimestamp returns a new Metric wrapping the provided Metric in a
+// way that it has an explicit timestamp set to the provided Time. This is only
+// useful in rare cases as the timestamp of a Prometheus metric should usually
+// be set by the Prometheus server during scraping. Exceptions include mirroring
+// metrics with given timestamps from other metric
+// sources.
+//
+// NewMetricWithTimestamp works best with MustNewConstMetric,
+// MustNewConstHistogram, and MustNewConstSummary, see example.
+//
+// Currently, the exposition formats used by Prometheus are limited to
+// millisecond resolution. Thus, the provided time will be rounded down to the
+// next full millisecond value.
+func NewMetricWithTimestamp(t time.Time, m Metric) Metric {
+	return timestampedMetric{Metric: m, t: t}
+}

vendor/github.com/prometheus/client_golang/prometheus/observer.go

@@ -0,0 +1,52 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Observer is the interface that wraps the Observe method, which is used by
+// Histogram and Summary to add observations.
+type Observer interface {
+	Observe(float64)
+}
+
+// The ObserverFunc type is an adapter to allow the use of ordinary
+// functions as Observers. If f is a function with the appropriate
+// signature, ObserverFunc(f) is an Observer that calls f.
+//
+// This adapter is usually used in connection with the Timer type, and there are
+// two general use cases:
+//
+// The most common one is to use a Gauge as the Observer for a Timer.
+// See the "Gauge" Timer example.
+//
+// The more advanced use case is to create a function that dynamically decides
+// which Observer to use for observing the duration. See the "Complex" Timer
+// example.
+type ObserverFunc func(float64)
+
+// Observe calls f(value). It implements Observer.
+func (f ObserverFunc) Observe(value float64) {
+	f(value)
+}
+
+// ObserverVec is an interface implemented by `HistogramVec` and `SummaryVec`.
+type ObserverVec interface {
+	GetMetricWith(Labels) (Observer, error)
+	GetMetricWithLabelValues(lvs ...string) (Observer, error)
+	With(Labels) Observer
+	WithLabelValues(...string) Observer
+	CurryWith(Labels) (ObserverVec, error)
+	MustCurryWith(Labels) ObserverVec
+
+	Collector
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector.go

@@ -13,46 +13,61 @@
 
 package prometheus
 
-import "github.com/prometheus/procfs"
+import (
+	"errors"
+	"os"
+)
 
 type processCollector struct {
-	pid             int
 	collectFn       func(chan<- Metric)
 	pidFn           func() (int, error)
+	reportErrors    bool
 	cpuTotal        *Desc
 	openFDs, maxFDs *Desc
-	vsize, rss      *Desc
+	vsize, maxVsize *Desc
+	rss             *Desc
 	startTime       *Desc
 }
 
-// NewProcessCollector returns a collector which exports the current state of
-// process metrics including cpu, memory and file descriptor usage as well as
-// the process start time for the given process id under the given namespace.
-func NewProcessCollector(pid int, namespace string) Collector {
-	return NewProcessCollectorPIDFn(
-		func() (int, error) { return pid, nil },
-		namespace,
-	)
+// ProcessCollectorOpts defines the behavior of a process metrics collector
+// created with NewProcessCollector.
+type ProcessCollectorOpts struct {
+	// PidFn returns the PID of the process the collector collects metrics
+	// for. It is called upon each collection. By default, the PID of the
+	// current process is used, as determined on construction time by
+	// calling os.Getpid().
+	PidFn func() (int, error)
+	// If non-empty, each of the collected metrics is prefixed by the
+	// provided string and an underscore ("_").
+	Namespace string
+	// If true, any error encountered during collection is reported as an
+	// invalid metric (see NewInvalidMetric). Otherwise, errors are ignored
+	// and the collected metrics will be incomplete. (Possibly, no metrics
+	// will be collected at all.) While that's usually not desired, it is
+	// appropriate for the common "mix-in" of process metrics, where process
+	// metrics are nice to have, but failing to collect them should not
+	// disrupt the collection of the remaining metrics.
+	ReportErrors bool
 }
 
-// NewProcessCollectorPIDFn returns a collector which exports the current state
-// of process metrics including cpu, memory and file descriptor usage as well
-// as the process start time under the given namespace. The given pidFn is
-// called on each collect and is used to determine the process to export
-// metrics for.
-func NewProcessCollectorPIDFn(
-	pidFn func() (int, error),
-	namespace string,
-) Collector {
+// NewProcessCollector returns a collector which exports the current state of
+// process metrics including CPU, memory and file descriptor usage as well as
+// the process start time. The detailed behavior is defined by the provided
+// ProcessCollectorOpts. The zero value of ProcessCollectorOpts creates a
+// collector for the current process with an empty namespace string and no error
+// reporting.
+//
+// The collector only works on operating systems with a Linux-style proc
+// filesystem and on Microsoft Windows. On other operating systems, it will not
+// collect any metrics.
+func NewProcessCollector(opts ProcessCollectorOpts) Collector {
 	ns := ""
-	if len(namespace) > 0 {
-		ns = namespace + "_"
+	if len(opts.Namespace) > 0 {
+		ns = opts.Namespace + "_"
 	}
 
-	c := processCollector{
-		pidFn:     pidFn,
-		collectFn: func(chan<- Metric) {},
-
+	c := &processCollector{
+		reportErrors: opts.ReportErrors,
 		cpuTotal: NewDesc(
 			ns+"process_cpu_seconds_total",
 			"Total user and system CPU time spent in seconds.",
@@ -73,6 +88,11 @@ func NewProcessCollectorPIDFn(
 			"Virtual memory size in bytes.",
 			nil, nil,
 		),
+		maxVsize: NewDesc(
+			ns+"process_virtual_memory_max_bytes",
+			"Maximum amount of virtual memory available in bytes.",
+			nil, nil,
+		),
 		rss: NewDesc(
 			ns+"process_resident_memory_bytes",
 			"Resident memory size in bytes.",
@@ -85,12 +105,23 @@ func NewProcessCollectorPIDFn(
 		),
 	}
 
-	// Set up process metric collection if supported by the runtime.
-	if _, err := procfs.NewStat(); err == nil {
-		c.collectFn = c.processCollect
+	if opts.PidFn == nil {
+		pid := os.Getpid()
+		c.pidFn = func() (int, error) { return pid, nil }
+	} else {
+		c.pidFn = opts.PidFn
 	}
 
-	return &c
+	// Set up process metric collection if supported by the runtime.
+	if canCollectProcess() {
+		c.collectFn = c.processCollect
+	} else {
+		c.collectFn = func(ch chan<- Metric) {
+			c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
+		}
+	}
+
+	return c
 }
 
 // Describe returns all descriptions of the collector.
@@ -99,6 +130,7 @@ func (c *processCollector) Describe(ch chan<- *Desc) {
 	ch <- c.openFDs
 	ch <- c.maxFDs
 	ch <- c.vsize
+	ch <- c.maxVsize
 	ch <- c.rss
 	ch <- c.startTime
 }
@@ -108,33 +140,12 @@ func (c *processCollector) Collect(ch chan<- Metric) {
 	c.collectFn(ch)
 }
 
-// TODO(ts): Bring back error reporting by reverting 7faf9e7 as soon as the
-// client allows users to configure the error behavior.
-func (c *processCollector) processCollect(ch chan<- Metric) {
-	pid, err := c.pidFn()
-	if err != nil {
+func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) {
+	if !c.reportErrors {
 		return
 	}
-
-	p, err := procfs.NewProc(pid)
-	if err != nil {
-		return
-	}
-
-	if stat, err := p.NewStat(); err == nil {
-		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
-		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
-		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
-		if startTime, err := stat.StartTime(); err == nil {
-			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
-		}
-	}
-
-	if fds, err := p.FileDescriptorsLen(); err == nil {
-		ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
-	}
-
-	if limits, err := p.NewLimits(); err == nil {
-		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
+	if desc == nil {
+		desc = NewInvalidDesc(err)
 	}
+	ch <- NewInvalidMetric(desc, err)
 }

vendor/github.com/prometheus/client_golang/prometheus/process_collector_other.go

@@ -0,0 +1,65 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !windows
+
+package prometheus
+
+import (
+	"github.com/prometheus/procfs"
+)
+
+func canCollectProcess() bool {
+	_, err := procfs.NewDefaultFS()
+	return err == nil
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	pid, err := c.pidFn()
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	p, err := procfs.NewProc(pid)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	if stat, err := p.Stat(); err == nil {
+		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
+		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
+		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
+		if startTime, err := stat.StartTime(); err == nil {
+			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
+		} else {
+			c.reportError(ch, c.startTime, err)
+		}
+	} else {
+		c.reportError(ch, nil, err)
+	}
+
+	if fds, err := p.FileDescriptorsLen(); err == nil {
+		ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
+	} else {
+		c.reportError(ch, c.openFDs, err)
+	}
+
+	if limits, err := p.Limits(); err == nil {
+		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
+		ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
+	} else {
+		c.reportError(ch, nil, err)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_windows.go

@@ -0,0 +1,112 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+func canCollectProcess() bool {
+	return true
+}
+
+var (
+	modpsapi    = syscall.NewLazyDLL("psapi.dll")
+	modkernel32 = syscall.NewLazyDLL("kernel32.dll")
+
+	procGetProcessMemoryInfo  = modpsapi.NewProc("GetProcessMemoryInfo")
+	procGetProcessHandleCount = modkernel32.NewProc("GetProcessHandleCount")
+)
+
+type processMemoryCounters struct {
+	// https://docs.microsoft.com/en-us/windows/desktop/api/psapi/ns-psapi-_process_memory_counters_ex
+	_                          uint32
+	PageFaultCount             uint32
+	PeakWorkingSetSize         uint64
+	WorkingSetSize             uint64
+	QuotaPeakPagedPoolUsage    uint64
+	QuotaPagedPoolUsage        uint64
+	QuotaPeakNonPagedPoolUsage uint64
+	QuotaNonPagedPoolUsage     uint64
+	PagefileUsage              uint64
+	PeakPagefileUsage          uint64
+	PrivateUsage               uint64
+}
+
+func getProcessMemoryInfo(handle windows.Handle) (processMemoryCounters, error) {
+	mem := processMemoryCounters{}
+	r1, _, err := procGetProcessMemoryInfo.Call(
+		uintptr(handle),
+		uintptr(unsafe.Pointer(&mem)),
+		uintptr(unsafe.Sizeof(mem)),
+	)
+	if r1 != 1 {
+		return mem, err
+	} else {
+		return mem, nil
+	}
+}
+
+func getProcessHandleCount(handle windows.Handle) (uint32, error) {
+	var count uint32
+	r1, _, err := procGetProcessHandleCount.Call(
+		uintptr(handle),
+		uintptr(unsafe.Pointer(&count)),
+	)
+	if r1 != 1 {
+		return 0, err
+	} else {
+		return count, nil
+	}
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	h, err := windows.GetCurrentProcess()
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	var startTime, exitTime, kernelTime, userTime windows.Filetime
+	err = windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.startTime, GaugeValue, float64(startTime.Nanoseconds()/1e9))
+	ch <- MustNewConstMetric(c.cpuTotal, CounterValue, fileTimeToSeconds(kernelTime)+fileTimeToSeconds(userTime))
+
+	mem, err := getProcessMemoryInfo(h)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(mem.PrivateUsage))
+	ch <- MustNewConstMetric(c.rss, GaugeValue, float64(mem.WorkingSetSize))
+
+	handles, err := getProcessHandleCount(h)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+	ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(handles))
+	ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(16*1024*1024)) // Windows has a hard-coded max limit, not per-process.
+}
+
+func fileTimeToSeconds(ft windows.Filetime) float64 {
+	return float64(uint64(ft.HighDateTime)<<32+uint64(ft.LowDateTime)) / 1e7
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go

@@ -0,0 +1,357 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+const (
+	closeNotifier = 1 << iota
+	flusher
+	hijacker
+	readerFrom
+	pusher
+)
+
+type delegator interface {
+	http.ResponseWriter
+
+	Status() int
+	Written() int64
+}
+
+type responseWriterDelegator struct {
+	http.ResponseWriter
+
+	status             int
+	written            int64
+	wroteHeader        bool
+	observeWriteHeader func(int)
+}
+
+func (r *responseWriterDelegator) Status() int {
+	return r.status
+}
+
+func (r *responseWriterDelegator) Written() int64 {
+	return r.written
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+	r.status = code
+	r.wroteHeader = true
+	r.ResponseWriter.WriteHeader(code)
+	if r.observeWriteHeader != nil {
+		r.observeWriteHeader(code)
+	}
+}
+
+func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+	if !r.wroteHeader {
+		r.WriteHeader(http.StatusOK)
+	}
+	n, err := r.ResponseWriter.Write(b)
+	r.written += int64(n)
+	return n, err
+}
+
+type closeNotifierDelegator struct{ *responseWriterDelegator }
+type flusherDelegator struct{ *responseWriterDelegator }
+type hijackerDelegator struct{ *responseWriterDelegator }
+type readerFromDelegator struct{ *responseWriterDelegator }
+type pusherDelegator struct{ *responseWriterDelegator }
+
+func (d closeNotifierDelegator) CloseNotify() <-chan bool {
+	//lint:ignore SA1019 http.CloseNotifier is deprecated but we don't want to
+	//remove support from client_golang yet.
+	return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+func (d flusherDelegator) Flush() {
+	d.ResponseWriter.(http.Flusher).Flush()
+}
+func (d hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return d.ResponseWriter.(http.Hijacker).Hijack()
+}
+func (d readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
+	if !d.wroteHeader {
+		d.WriteHeader(http.StatusOK)
+	}
+	n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re)
+	d.written += n
+	return n, err
+}
+func (d pusherDelegator) Push(target string, opts *http.PushOptions) error {
+	return d.ResponseWriter.(http.Pusher).Push(target, opts)
+}
+
+var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32)
+
+func init() {
+	// TODO(beorn7): Code generation would help here.
+	pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0
+		return d
+	}
+	pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1
+		return closeNotifierDelegator{d}
+	}
+	pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2
+		return flusherDelegator{d}
+	}
+	pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3
+		return struct {
+			*responseWriterDelegator
+			http.Flusher
+			http.CloseNotifier
+		}{d, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4
+		return hijackerDelegator{d}
+	}
+	pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.CloseNotifier
+		}{d, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+		}{d, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8
+		return readerFromDelegator{d}
+	}
+	pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+		}{d, readerFromDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16
+		return pusherDelegator{d}
+	}
+	pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+		}{d, pusherDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+		}{d, pusherDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { //23
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+		}{d, pusherDelegator{d}, readerFromDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+}
+
+func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
+	d := &responseWriterDelegator{
+		ResponseWriter:     w,
+		observeWriteHeader: observeWriteHeaderFunc,
+	}
+
+	id := 0
+	//lint:ignore SA1019 http.CloseNotifier is deprecated but we don't want to
+	//remove support from client_golang yet.
+	if _, ok := w.(http.CloseNotifier); ok {
+		id += closeNotifier
+	}
+	if _, ok := w.(http.Flusher); ok {
+		id += flusher
+	}
+	if _, ok := w.(http.Hijacker); ok {
+		id += hijacker
+	}
+	if _, ok := w.(io.ReaderFrom); ok {
+		id += readerFrom
+	}
+	if _, ok := w.(http.Pusher); ok {
+		id += pusher
+	}
+
+	return pickDelegator[id](d)
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -11,31 +11,34 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Copyright (c) 2013, The Prometheus Authors
-// All rights reserved.
+// Package promhttp provides tooling around HTTP servers and clients.
 //
-// Use of this source code is governed by a BSD-style license that can be found
-// in the LICENSE file.
-
-// Package promhttp contains functions to create http.Handler instances to
-// expose Prometheus metrics via HTTP. In later versions of this package, it
-// will also contain tooling to instrument instances of http.Handler and
-// http.RoundTripper.
+// First, the package allows the creation of http.Handler instances to expose
+// Prometheus metrics via HTTP. promhttp.Handler acts on the
+// prometheus.DefaultGatherer. With HandlerFor, you can create a handler for a
+// custom registry or anything that implements the Gatherer interface. It also
+// allows the creation of handlers that act differently on errors or allow to
+// log errors.
 //
-// promhttp.Handler acts on the prometheus.DefaultGatherer. With HandlerFor,
-// you can create a handler for a custom registry or anything that implements
-// the Gatherer interface. It also allows to create handlers that act
-// differently on errors or allow to log errors.
+// Second, the package provides tooling to instrument instances of http.Handler
+// via middleware. Middleware wrappers follow the naming scheme
+// InstrumentHandlerX, where X describes the intended use of the middleware.
+// See each function's doc comment for specific details.
+//
+// Finally, the package allows for an http.RoundTripper to be instrumented via
+// middleware. Middleware wrappers follow the naming scheme
+// InstrumentRoundTripperX, where X describes the intended use of the
+// middleware. See each function's doc comment for specific details.
 package promhttp
 
 import (
-	"bytes"
 	"compress/gzip"
 	"fmt"
 	"io"
 	"net/http"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/prometheus/common/expfmt"
 
@@ -44,99 +47,204 @@ import (
 
 const (
 	contentTypeHeader     = "Content-Type"
-	contentLengthHeader   = "Content-Length"
 	contentEncodingHeader = "Content-Encoding"
 	acceptEncodingHeader  = "Accept-Encoding"
 )
 
-var bufPool sync.Pool
-
-func getBuf() *bytes.Buffer {
-	buf := bufPool.Get()
-	if buf == nil {
-		return &bytes.Buffer{}
-	}
-	return buf.(*bytes.Buffer)
+var gzipPool = sync.Pool{
+	New: func() interface{} {
+		return gzip.NewWriter(nil)
+	},
 }
 
-func giveBuf(buf *bytes.Buffer) {
-	buf.Reset()
-	bufPool.Put(buf)
-}
-
-// Handler returns an HTTP handler for the prometheus.DefaultGatherer. The
-// Handler uses the default HandlerOpts, i.e. report the first error as an HTTP
-// error, no error logging, and compression if requested by the client.
+// Handler returns an http.Handler for the prometheus.DefaultGatherer, using
+// default HandlerOpts, i.e. it reports the first error as an HTTP error, it has
+// no error logging, and it applies compression if requested by the client.
 //
-// If you want to create a Handler for the DefaultGatherer with different
-// HandlerOpts, create it with HandlerFor with prometheus.DefaultGatherer and
-// your desired HandlerOpts.
+// The returned http.Handler is already instrumented using the
+// InstrumentMetricHandler function and the prometheus.DefaultRegisterer. If you
+// create multiple http.Handlers by separate calls of the Handler function, the
+// metrics used for instrumentation will be shared between them, providing
+// global scrape counts.
+//
+// This function is meant to cover the bulk of basic use cases. If you are doing
+// anything that requires more customization (including using a non-default
+// Gatherer, different instrumentation, and non-default HandlerOpts), use the
+// HandlerFor function. See there for details.
 func Handler() http.Handler {
-	return HandlerFor(prometheus.DefaultGatherer, HandlerOpts{})
+	return InstrumentMetricHandler(
+		prometheus.DefaultRegisterer, HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}),
+	)
 }
 
-// HandlerFor returns an http.Handler for the provided Gatherer. The behavior
-// of the Handler is defined by the provided HandlerOpts.
+// HandlerFor returns an uninstrumented http.Handler for the provided
+// Gatherer. The behavior of the Handler is defined by the provided
+// HandlerOpts. Thus, HandlerFor is useful to create http.Handlers for custom
+// Gatherers, with non-default HandlerOpts, and/or with custom (or no)
+// instrumentation. Use the InstrumentMetricHandler function to apply the same
+// kind of instrumentation as it is used by the Handler function.
 func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+	var (
+		inFlightSem chan struct{}
+		errCnt      = prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "promhttp_metric_handler_errors_total",
+				Help: "Total number of internal errors encountered by the promhttp metric handler.",
+			},
+			[]string{"cause"},
+		)
+	)
+
+	if opts.MaxRequestsInFlight > 0 {
+		inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
+	}
+	if opts.Registry != nil {
+		// Initialize all possibilites that can occur below.
+		errCnt.WithLabelValues("gathering")
+		errCnt.WithLabelValues("encoding")
+		if err := opts.Registry.Register(errCnt); err != nil {
+			if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+				errCnt = are.ExistingCollector.(*prometheus.CounterVec)
+			} else {
+				panic(err)
+			}
+		}
+	}
+
+	h := http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
+		if inFlightSem != nil {
+			select {
+			case inFlightSem <- struct{}{}: // All good, carry on.
+				defer func() { <-inFlightSem }()
+			default:
+				http.Error(rsp, fmt.Sprintf(
+					"Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight,
+				), http.StatusServiceUnavailable)
+				return
+			}
+		}
 		mfs, err := reg.Gather()
 		if err != nil {
 			if opts.ErrorLog != nil {
 				opts.ErrorLog.Println("error gathering metrics:", err)
 			}
+			errCnt.WithLabelValues("gathering").Inc()
 			switch opts.ErrorHandling {
 			case PanicOnError:
 				panic(err)
 			case ContinueOnError:
 				if len(mfs) == 0 {
-					http.Error(w, "No metrics gathered, last error:\n\n"+err.Error(), http.StatusInternalServerError)
+					// Still report the error if no metrics have been gathered.
+					httpError(rsp, err)
 					return
 				}
 			case HTTPErrorOnError:
-				http.Error(w, "An error has occurred during metrics gathering:\n\n"+err.Error(), http.StatusInternalServerError)
+				httpError(rsp, err)
 				return
 			}
 		}
 
 		contentType := expfmt.Negotiate(req.Header)
-		buf := getBuf()
-		defer giveBuf(buf)
-		writer, encoding := decorateWriter(req, buf, opts.DisableCompression)
-		enc := expfmt.NewEncoder(writer, contentType)
+		header := rsp.Header()
+		header.Set(contentTypeHeader, string(contentType))
+
+		w := io.Writer(rsp)
+		if !opts.DisableCompression && gzipAccepted(req.Header) {
+			header.Set(contentEncodingHeader, "gzip")
+			gz := gzipPool.Get().(*gzip.Writer)
+			defer gzipPool.Put(gz)
+
+			gz.Reset(w)
+			defer gz.Close()
+
+			w = gz
+		}
+
+		enc := expfmt.NewEncoder(w, contentType)
+
 		var lastErr error
 		for _, mf := range mfs {
 			if err := enc.Encode(mf); err != nil {
 				lastErr = err
 				if opts.ErrorLog != nil {
-					opts.ErrorLog.Println("error encoding metric family:", err)
+					opts.ErrorLog.Println("error encoding and sending metric family:", err)
 				}
+				errCnt.WithLabelValues("encoding").Inc()
 				switch opts.ErrorHandling {
 				case PanicOnError:
 					panic(err)
 				case ContinueOnError:
 					// Handled later.
 				case HTTPErrorOnError:
-					http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
+					httpError(rsp, err)
 					return
 				}
 			}
 		}
-		if closer, ok := writer.(io.Closer); ok {
-			closer.Close()
+
+		if lastErr != nil {
+			httpError(rsp, lastErr)
 		}
-		if lastErr != nil && buf.Len() == 0 {
-			http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
-			return
-		}
-		header := w.Header()
-		header.Set(contentTypeHeader, string(contentType))
-		header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
-		if encoding != "" {
-			header.Set(contentEncodingHeader, encoding)
-		}
-		w.Write(buf.Bytes())
-		// TODO(beorn7): Consider streaming serving of metrics.
 	})
+
+	if opts.Timeout <= 0 {
+		return h
+	}
+	return http.TimeoutHandler(h, opts.Timeout, fmt.Sprintf(
+		"Exceeded configured timeout of %v.\n",
+		opts.Timeout,
+	))
+}
+
+// InstrumentMetricHandler is usually used with an http.Handler returned by the
+// HandlerFor function. It instruments the provided http.Handler with two
+// metrics: A counter vector "promhttp_metric_handler_requests_total" to count
+// scrapes partitioned by HTTP status code, and a gauge
+// "promhttp_metric_handler_requests_in_flight" to track the number of
+// simultaneous scrapes. This function idempotently registers collectors for
+// both metrics with the provided Registerer. It panics if the registration
+// fails. The provided metrics are useful to see how many scrapes hit the
+// monitored target (which could be from different Prometheus servers or other
+// scrapers), and how often they overlap (which would result in more than one
+// scrape in flight at the same time). Note that the scrapes-in-flight gauge
+// will contain the scrape by which it is exposed, while the scrape counter will
+// only get incremented after the scrape is complete (as only then the status
+// code is known). For tracking scrape durations, use the
+// "scrape_duration_seconds" gauge created by the Prometheus server upon each
+// scrape.
+func InstrumentMetricHandler(reg prometheus.Registerer, handler http.Handler) http.Handler {
+	cnt := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "promhttp_metric_handler_requests_total",
+			Help: "Total number of scrapes by HTTP status code.",
+		},
+		[]string{"code"},
+	)
+	// Initialize the most likely HTTP status codes.
+	cnt.WithLabelValues("200")
+	cnt.WithLabelValues("500")
+	cnt.WithLabelValues("503")
+	if err := reg.Register(cnt); err != nil {
+		if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+			cnt = are.ExistingCollector.(*prometheus.CounterVec)
+		} else {
+			panic(err)
+		}
+	}
+
+	gge := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "promhttp_metric_handler_requests_in_flight",
+		Help: "Current number of scrapes being served.",
+	})
+	if err := reg.Register(gge); err != nil {
+		if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+			gge = are.ExistingCollector.(prometheus.Gauge)
+		} else {
+			panic(err)
+		}
+	}
+
+	return InstrumentHandlerCounter(cnt, InstrumentHandlerInFlight(gge, handler))
 }
 
 // HandlerErrorHandling defines how a Handler serving metrics will handle
@@ -152,9 +260,12 @@ const (
 	// Ignore errors and try to serve as many metrics as possible.  However,
 	// if no metrics can be served, serve an HTTP status code 500 and the
 	// last error message in the body. Only use this in deliberate "best
-	// effort" metrics collection scenarios. It is recommended to at least
-	// log errors (by providing an ErrorLog in HandlerOpts) to not mask
-	// errors completely.
+	// effort" metrics collection scenarios. In this case, it is highly
+	// recommended to provide other means of detecting errors: By setting an
+	// ErrorLog in HandlerOpts, the errors are logged. By providing a
+	// Registry in HandlerOpts, the exposed metrics include an error counter
+	// "promhttp_metric_handler_errors_total", which can be used for
+	// alerts.
 	ContinueOnError
 	// Panic upon the first error encountered (useful for "crash only" apps).
 	PanicOnError
@@ -177,25 +288,62 @@ type HandlerOpts struct {
 	// logged regardless of the configured ErrorHandling provided ErrorLog
 	// is not nil.
 	ErrorHandling HandlerErrorHandling
+	// If Registry is not nil, it is used to register a metric
+	// "promhttp_metric_handler_errors_total", partitioned by "cause". A
+	// failed registration causes a panic. Note that this error counter is
+	// different from the instrumentation you get from the various
+	// InstrumentHandler... helpers. It counts errors that don't necessarily
+	// result in a non-2xx HTTP status code. There are two typical cases:
+	// (1) Encoding errors that only happen after streaming of the HTTP body
+	// has already started (and the status code 200 has been sent). This
+	// should only happen with custom collectors. (2) Collection errors with
+	// no effect on the HTTP status code because ErrorHandling is set to
+	// ContinueOnError.
+	Registry prometheus.Registerer
 	// If DisableCompression is true, the handler will never compress the
 	// response, even if requested by the client.
 	DisableCompression bool
+	// The number of concurrent HTTP requests is limited to
+	// MaxRequestsInFlight. Additional requests are responded to with 503
+	// Service Unavailable and a suitable message in the body. If
+	// MaxRequestsInFlight is 0 or negative, no limit is applied.
+	MaxRequestsInFlight int
+	// If handling a request takes longer than Timeout, it is responded to
+	// with 503 ServiceUnavailable and a suitable Message. No timeout is
+	// applied if Timeout is 0 or negative. Note that with the current
+	// implementation, reaching the timeout simply ends the HTTP requests as
+	// described above (and even that only if sending of the body hasn't
+	// started yet), while the bulk work of gathering all the metrics keeps
+	// running in the background (with the eventual result to be thrown
+	// away). Until the implementation is improved, it is recommended to
+	// implement a separate timeout in potentially slow Collectors.
+	Timeout time.Duration
 }
 
-// decorateWriter wraps a writer to handle gzip compression if requested.  It
-// returns the decorated writer and the appropriate "Content-Encoding" header
-// (which is empty if no compression is enabled).
-func decorateWriter(request *http.Request, writer io.Writer, compressionDisabled bool) (io.Writer, string) {
-	if compressionDisabled {
-		return writer, ""
-	}
-	header := request.Header.Get(acceptEncodingHeader)
-	parts := strings.Split(header, ",")
+// gzipAccepted returns whether the client will accept gzip-encoded content.
+func gzipAccepted(header http.Header) bool {
+	a := header.Get(acceptEncodingHeader)
+	parts := strings.Split(a, ",")
 	for _, part := range parts {
-		part := strings.TrimSpace(part)
+		part = strings.TrimSpace(part)
 		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
-			return gzip.NewWriter(writer), "gzip"
+			return true
 		}
 	}
-	return writer, ""
+	return false
+}
+
+// httpError removes any content-encoding header and then calls http.Error with
+// the provided error and http.StatusInternalServerErrer. Error contents is
+// supposed to be uncompressed plain text. However, same as with a plain
+// http.Error, any header settings will be void if the header has already been
+// sent. The error message will still be written to the writer, but it will
+// probably be of limited use.
+func httpError(rsp http.ResponseWriter, err error) {
+	rsp.Header().Del(contentEncodingHeader)
+	http.Error(
+		rsp,
+		"An error has occurred while serving metrics:\n\n"+err.Error(),
+		http.StatusInternalServerError,
+	)
 }

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go

@@ -0,0 +1,219 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"crypto/tls"
+	"net/http"
+	"net/http/httptrace"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// The RoundTripperFunc type is an adapter to allow the use of ordinary
+// functions as RoundTrippers. If f is a function with the appropriate
+// signature, RountTripperFunc(f) is a RoundTripper that calls f.
+type RoundTripperFunc func(req *http.Request) (*http.Response, error)
+
+// RoundTrip implements the RoundTripper interface.
+func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
+	return rt(r)
+}
+
+// InstrumentRoundTripperInFlight is a middleware that wraps the provided
+// http.RoundTripper. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.RoundTripper.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripper) RoundTripperFunc {
+	return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		gauge.Inc()
+		defer gauge.Dec()
+		return next.RoundTrip(r)
+	})
+}
+
+// InstrumentRoundTripperCounter is a middleware that wraps the provided
+// http.RoundTripper to observe the request result with the provided CounterVec.
+// The CounterVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. Partitioning of the CounterVec happens by HTTP status code
+// and/or HTTP method if the respective instance label names are present in the
+// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
+//
+// If the wrapped RoundTripper panics or returns a non-nil error, the Counter
+// is not incremented.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.RoundTripper) RoundTripperFunc {
+	code, method := checkLabels(counter)
+
+	return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		resp, err := next.RoundTrip(r)
+		if err == nil {
+			counter.With(labels(code, method, r.Method, resp.StatusCode)).Inc()
+		}
+		return resp, err
+	})
+}
+
+// InstrumentRoundTripperDuration is a middleware that wraps the provided
+// http.RoundTripper to observe the request duration with the provided
+// ObserverVec.  The ObserverVec must have zero, one, or two non-const
+// non-curried labels. For those, the only allowed label names are "code" and
+// "method". The function panics otherwise. The Observe method of the Observer
+// in the ObserverVec is called with the request duration in
+// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped RoundTripper panics or returns a non-nil error, no values are
+// reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentRoundTripperDuration(obs prometheus.ObserverVec, next http.RoundTripper) RoundTripperFunc {
+	code, method := checkLabels(obs)
+
+	return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		start := time.Now()
+		resp, err := next.RoundTrip(r)
+		if err == nil {
+			obs.With(labels(code, method, r.Method, resp.StatusCode)).Observe(time.Since(start).Seconds())
+		}
+		return resp, err
+	})
+}
+
+// InstrumentTrace is used to offer flexibility in instrumenting the available
+// httptrace.ClientTrace hook functions. Each function is passed a float64
+// representing the time in seconds since the start of the http request. A user
+// may choose to use separately buckets Histograms, or implement custom
+// instance labels on a per function basis.
+type InstrumentTrace struct {
+	GotConn              func(float64)
+	PutIdleConn          func(float64)
+	GotFirstResponseByte func(float64)
+	Got100Continue       func(float64)
+	DNSStart             func(float64)
+	DNSDone              func(float64)
+	ConnectStart         func(float64)
+	ConnectDone          func(float64)
+	TLSHandshakeStart    func(float64)
+	TLSHandshakeDone     func(float64)
+	WroteHeaders         func(float64)
+	Wait100Continue      func(float64)
+	WroteRequest         func(float64)
+}
+
+// InstrumentRoundTripperTrace is a middleware that wraps the provided
+// RoundTripper and reports times to hook functions provided in the
+// InstrumentTrace struct. Hook functions that are not present in the provided
+// InstrumentTrace struct are ignored. Times reported to the hook functions are
+// time since the start of the request. Only with Go1.9+, those times are
+// guaranteed to never be negative. (Earlier Go versions are not using a
+// monotonic clock.) Note that partitioning of Histograms is expensive and
+// should be used judiciously.
+//
+// For hook functions that receive an error as an argument, no observations are
+// made in the event of a non-nil error value.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) RoundTripperFunc {
+	return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+		start := time.Now()
+
+		trace := &httptrace.ClientTrace{
+			GotConn: func(_ httptrace.GotConnInfo) {
+				if it.GotConn != nil {
+					it.GotConn(time.Since(start).Seconds())
+				}
+			},
+			PutIdleConn: func(err error) {
+				if err != nil {
+					return
+				}
+				if it.PutIdleConn != nil {
+					it.PutIdleConn(time.Since(start).Seconds())
+				}
+			},
+			DNSStart: func(_ httptrace.DNSStartInfo) {
+				if it.DNSStart != nil {
+					it.DNSStart(time.Since(start).Seconds())
+				}
+			},
+			DNSDone: func(_ httptrace.DNSDoneInfo) {
+				if it.DNSDone != nil {
+					it.DNSDone(time.Since(start).Seconds())
+				}
+			},
+			ConnectStart: func(_, _ string) {
+				if it.ConnectStart != nil {
+					it.ConnectStart(time.Since(start).Seconds())
+				}
+			},
+			ConnectDone: func(_, _ string, err error) {
+				if err != nil {
+					return
+				}
+				if it.ConnectDone != nil {
+					it.ConnectDone(time.Since(start).Seconds())
+				}
+			},
+			GotFirstResponseByte: func() {
+				if it.GotFirstResponseByte != nil {
+					it.GotFirstResponseByte(time.Since(start).Seconds())
+				}
+			},
+			Got100Continue: func() {
+				if it.Got100Continue != nil {
+					it.Got100Continue(time.Since(start).Seconds())
+				}
+			},
+			TLSHandshakeStart: func() {
+				if it.TLSHandshakeStart != nil {
+					it.TLSHandshakeStart(time.Since(start).Seconds())
+				}
+			},
+			TLSHandshakeDone: func(_ tls.ConnectionState, err error) {
+				if err != nil {
+					return
+				}
+				if it.TLSHandshakeDone != nil {
+					it.TLSHandshakeDone(time.Since(start).Seconds())
+				}
+			},
+			WroteHeaders: func() {
+				if it.WroteHeaders != nil {
+					it.WroteHeaders(time.Since(start).Seconds())
+				}
+			},
+			Wait100Continue: func() {
+				if it.Wait100Continue != nil {
+					it.Wait100Continue(time.Since(start).Seconds())
+				}
+			},
+			WroteRequest: func(_ httptrace.WroteRequestInfo) {
+				if it.WroteRequest != nil {
+					it.WroteRequest(time.Since(start).Seconds())
+				}
+			},
+		}
+		r = r.WithContext(httptrace.WithClientTrace(r.Context(), trace))
+
+		return next.RoundTrip(r)
+	})
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go

@@ -0,0 +1,447 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// magicString is used for the hacky label test in checkLabels. Remove once fixed.
+const magicString = "zZgWfBxLqvG8kc8IMv3POi2Bb0tZI3vAnBx+gBaFi9FyPzB/CzKUer1yufDa"
+
+// InstrumentHandlerInFlight is a middleware that wraps the provided
+// http.Handler. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.Handler.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		g.Inc()
+		defer g.Dec()
+		next.ServeHTTP(w, r)
+	})
+}
+
+// InstrumentHandlerDuration is a middleware that wraps the provided
+// http.Handler to observe the request duration with the provided ObserverVec.
+// The ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the request duration in seconds. Partitioning happens by HTTP
+// status code and/or HTTP method if the respective instance label names are
+// present in the ObserverVec. For unpartitioned observations, use an
+// ObserverVec with zero labels. Note that partitioning of Histograms is
+// expensive and should be used judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+	code, method := checkLabels(obs)
+
+	if code {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			now := time.Now()
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+
+			obs.With(labels(code, method, r.Method, d.Status())).Observe(time.Since(now).Seconds())
+		})
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		now := time.Now()
+		next.ServeHTTP(w, r)
+		obs.With(labels(code, method, r.Method, 0)).Observe(time.Since(now).Seconds())
+	})
+}
+
+// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler
+// to observe the request result with the provided CounterVec.  The CounterVec
+// must have zero, one, or two non-const non-curried labels. For those, the only
+// allowed label names are "code" and "method". The function panics
+// otherwise. Partitioning of the CounterVec happens by HTTP status code and/or
+// HTTP method if the respective instance label names are present in the
+// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, the Counter is not incremented.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) http.HandlerFunc {
+	code, method := checkLabels(counter)
+
+	if code {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+			counter.With(labels(code, method, r.Method, d.Status())).Inc()
+		})
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		next.ServeHTTP(w, r)
+		counter.With(labels(code, method, r.Method, 0)).Inc()
+	})
+}
+
+// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided
+// http.Handler to observe with the provided ObserverVec the request duration
+// until the response headers are written. The ObserverVec must have zero, one,
+// or two non-const non-curried labels. For those, the only allowed label names
+// are "code" and "method". The function panics otherwise. The Observe method of
+// the Observer in the ObserverVec is called with the request duration in
+// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped Handler panics before calling WriteHeader, no value is
+// reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+	code, method := checkLabels(obs)
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		now := time.Now()
+		d := newDelegator(w, func(status int) {
+			obs.With(labels(code, method, r.Method, status)).Observe(time.Since(now).Seconds())
+		})
+		next.ServeHTTP(d, r)
+	})
+}
+
+// InstrumentHandlerRequestSize is a middleware that wraps the provided
+// http.Handler to observe the request size with the provided ObserverVec.  The
+// ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the request size in bytes. Partitioning happens by HTTP status
+// code and/or HTTP method if the respective instance label names are present in
+// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
+// labels. Note that partitioning of Histograms is expensive and should be used
+// judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+	code, method := checkLabels(obs)
+
+	if code {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			d := newDelegator(w, nil)
+			next.ServeHTTP(d, r)
+			size := computeApproximateRequestSize(r)
+			obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(size))
+		})
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		next.ServeHTTP(w, r)
+		size := computeApproximateRequestSize(r)
+		obs.With(labels(code, method, r.Method, 0)).Observe(float64(size))
+	})
+}
+
+// InstrumentHandlerResponseSize is a middleware that wraps the provided
+// http.Handler to observe the response size with the provided ObserverVec.  The
+// ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the response size in bytes. Partitioning happens by HTTP status
+// code and/or HTTP method if the respective instance label names are present in
+// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
+// labels. Note that partitioning of Histograms is expensive and should be used
+// judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerResponseSize(obs prometheus.ObserverVec, next http.Handler) http.Handler {
+	code, method := checkLabels(obs)
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		d := newDelegator(w, nil)
+		next.ServeHTTP(d, r)
+		obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(d.Written()))
+	})
+}
+
+func checkLabels(c prometheus.Collector) (code bool, method bool) {
+	// TODO(beorn7): Remove this hacky way to check for instance labels
+	// once Descriptors can have their dimensionality queried.
+	var (
+		desc *prometheus.Desc
+		m    prometheus.Metric
+		pm   dto.Metric
+		lvs  []string
+	)
+
+	// Get the Desc from the Collector.
+	descc := make(chan *prometheus.Desc, 1)
+	c.Describe(descc)
+
+	select {
+	case desc = <-descc:
+	default:
+		panic("no description provided by collector")
+	}
+	select {
+	case <-descc:
+		panic("more than one description provided by collector")
+	default:
+	}
+
+	close(descc)
+
+	// Create a ConstMetric with the Desc. Since we don't know how many
+	// variable labels there are, try for as long as it needs.
+	for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) {
+		m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...)
+	}
+
+	// Write out the metric into a proto message and look at the labels.
+	// If the value is not the magicString, it is a constLabel, which doesn't interest us.
+	// If the label is curried, it doesn't interest us.
+	// In all other cases, only "code" or "method" is allowed.
+	if err := m.Write(&pm); err != nil {
+		panic("error checking metric for labels")
+	}
+	for _, label := range pm.Label {
+		name, value := label.GetName(), label.GetValue()
+		if value != magicString || isLabelCurried(c, name) {
+			continue
+		}
+		switch name {
+		case "code":
+			code = true
+		case "method":
+			method = true
+		default:
+			panic("metric partitioned with non-supported labels")
+		}
+	}
+	return
+}
+
+func isLabelCurried(c prometheus.Collector, label string) bool {
+	// This is even hackier than the label test above.
+	// We essentially try to curry again and see if it works.
+	// But for that, we need to type-convert to the two
+	// types we use here, ObserverVec or *CounterVec.
+	switch v := c.(type) {
+	case *prometheus.CounterVec:
+		if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+			return false
+		}
+	case prometheus.ObserverVec:
+		if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+			return false
+		}
+	default:
+		panic("unsupported metric vec type")
+	}
+	return true
+}
+
+// emptyLabels is a one-time allocation for non-partitioned metrics to avoid
+// unnecessary allocations on each request.
+var emptyLabels = prometheus.Labels{}
+
+func labels(code, method bool, reqMethod string, status int) prometheus.Labels {
+	if !(code || method) {
+		return emptyLabels
+	}
+	labels := prometheus.Labels{}
+
+	if code {
+		labels["code"] = sanitizeCode(status)
+	}
+	if method {
+		labels["method"] = sanitizeMethod(reqMethod)
+	}
+
+	return labels
+}
+
+func computeApproximateRequestSize(r *http.Request) int {
+	s := 0
+	if r.URL != nil {
+		s += len(r.URL.String())
+	}
+
+	s += len(r.Method)
+	s += len(r.Proto)
+	for name, values := range r.Header {
+		s += len(name)
+		for _, value := range values {
+			s += len(value)
+		}
+	}
+	s += len(r.Host)
+
+	// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
+
+	if r.ContentLength != -1 {
+		s += int(r.ContentLength)
+	}
+	return s
+}
+
+func sanitizeMethod(m string) string {
+	switch m {
+	case "GET", "get":
+		return "get"
+	case "PUT", "put":
+		return "put"
+	case "HEAD", "head":
+		return "head"
+	case "POST", "post":
+		return "post"
+	case "DELETE", "delete":
+		return "delete"
+	case "CONNECT", "connect":
+		return "connect"
+	case "OPTIONS", "options":
+		return "options"
+	case "NOTIFY", "notify":
+		return "notify"
+	default:
+		return strings.ToLower(m)
+	}
+}
+
+// If the wrapped http.Handler has not set a status code, i.e. the value is
+// currently 0, santizeCode will return 200, for consistency with behavior in
+// the stdlib.
+func sanitizeCode(s int) string {
+	switch s {
+	case 100:
+		return "100"
+	case 101:
+		return "101"
+
+	case 200, 0:
+		return "200"
+	case 201:
+		return "201"
+	case 202:
+		return "202"
+	case 203:
+		return "203"
+	case 204:
+		return "204"
+	case 205:
+		return "205"
+	case 206:
+		return "206"
+
+	case 300:
+		return "300"
+	case 301:
+		return "301"
+	case 302:
+		return "302"
+	case 304:
+		return "304"
+	case 305:
+		return "305"
+	case 307:
+		return "307"
+
+	case 400:
+		return "400"
+	case 401:
+		return "401"
+	case 402:
+		return "402"
+	case 403:
+		return "403"
+	case 404:
+		return "404"
+	case 405:
+		return "405"
+	case 406:
+		return "406"
+	case 407:
+		return "407"
+	case 408:
+		return "408"
+	case 409:
+		return "409"
+	case 410:
+		return "410"
+	case 411:
+		return "411"
+	case 412:
+		return "412"
+	case 413:
+		return "413"
+	case 414:
+		return "414"
+	case 415:
+		return "415"
+	case 416:
+		return "416"
+	case 417:
+		return "417"
+	case 418:
+		return "418"
+
+	case 500:
+		return "500"
+	case 501:
+		return "501"
+	case 502:
+		return "502"
+	case 503:
+		return "503"
+	case 504:
+		return "504"
+	case 505:
+		return "505"
+
+	case 428:
+		return "428"
+	case 429:
+		return "429"
+	case 431:
+		return "431"
+	case 511:
+		return "511"
+
+	default:
+		return strconv.Itoa(s)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/registry.go

@@ -15,15 +15,22 @@ package prometheus
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
+	"path/filepath"
+	"runtime"
 	"sort"
+	"strings"
 	"sync"
+	"unicode/utf8"
 
 	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/expfmt"
 
 	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
 )
 
 const (
@@ -35,13 +42,14 @@ const (
 // DefaultRegisterer and DefaultGatherer are the implementations of the
 // Registerer and Gatherer interface a number of convenience functions in this
 // package act on. Initially, both variables point to the same Registry, which
-// has a process collector (see NewProcessCollector) and a Go collector (see
-// NewGoCollector) already registered. This approach to keep default instances
-// as global state mirrors the approach of other packages in the Go standard
-// library. Note that there are caveats. Change the variables with caution and
-// only if you understand the consequences. Users who want to avoid global state
-// altogether should not use the convenience function and act on custom
-// instances instead.
+// has a process collector (currently on Linux only, see NewProcessCollector)
+// and a Go collector (see NewGoCollector, in particular the note about
+// stop-the-world implication with Go versions older than 1.9) already
+// registered. This approach to keep default instances as global state mirrors
+// the approach of other packages in the Go standard library. Note that there
+// are caveats. Change the variables with caution and only if you understand the
+// consequences. Users who want to avoid global state altogether should not use
+// the convenience functions and act on custom instances instead.
 var (
 	defaultRegistry              = NewRegistry()
 	DefaultRegisterer Registerer = defaultRegistry
@@ -49,7 +57,7 @@ var (
 )
 
 func init() {
-	MustRegister(NewProcessCollector(os.Getpid(), ""))
+	MustRegister(NewProcessCollector(ProcessCollectorOpts{}))
 	MustRegister(NewGoCollector())
 }
 
@@ -65,7 +73,8 @@ func NewRegistry() *Registry {
 
 // NewPedanticRegistry returns a registry that checks during collection if each
 // collected Metric is consistent with its reported Desc, and if the Desc has
-// actually been registered with the registry.
+// actually been registered with the registry. Unchecked Collectors (those whose
+// Describe methed does not yield any descriptors) are excluded from the check.
 //
 // Usually, a Registry will be happy as long as the union of all collected
 // Metrics is consistent and valid even if some metrics are not consistent with
@@ -80,7 +89,7 @@ func NewPedanticRegistry() *Registry {
 
 // Registerer is the interface for the part of a registry in charge of
 // registering and unregistering. Users of custom registries should use
-// Registerer as type for registration purposes (rather then the Registry type
+// Registerer as type for registration purposes (rather than the Registry type
 // directly). In that way, they are free to use custom Registerer implementation
 // (e.g. for testing purposes).
 type Registerer interface {
@@ -95,8 +104,13 @@ type Registerer interface {
 	// returned error is an instance of AlreadyRegisteredError, which
 	// contains the previously registered Collector.
 	//
-	// It is in general not safe to register the same Collector multiple
-	// times concurrently.
+	// A Collector whose Describe method does not yield any Desc is treated
+	// as unchecked. Registration will always succeed. No check for
+	// re-registering (see previous paragraph) is performed. Thus, the
+	// caller is responsible for not double-registering the same unchecked
+	// Collector, and for providing a Collector that will not cause
+	// inconsistent metrics on collection. (This would lead to scrape
+	// errors.)
 	Register(Collector) error
 	// MustRegister works like Register but registers any number of
 	// Collectors and panics upon the first registration that causes an
@@ -105,7 +119,9 @@ type Registerer interface {
 	// Unregister unregisters the Collector that equals the Collector passed
 	// in as an argument.  (Two Collectors are considered equal if their
 	// Describe method yields the same set of descriptors.) The function
-	// returns whether a Collector was unregistered.
+	// returns whether a Collector was unregistered. Note that an unchecked
+	// Collector cannot be unregistered (as its Describe method does not
+	// yield any descriptor).
 	//
 	// Note that even after unregistering, it will not be possible to
 	// register a new Collector that is inconsistent with the unregistered
@@ -123,15 +139,23 @@ type Registerer interface {
 type Gatherer interface {
 	// Gather calls the Collect method of the registered Collectors and then
 	// gathers the collected metrics into a lexicographically sorted slice
-	// of MetricFamily protobufs. Even if an error occurs, Gather attempts
-	// to gather as many metrics as possible. Hence, if a non-nil error is
-	// returned, the returned MetricFamily slice could be nil (in case of a
-	// fatal error that prevented any meaningful metric collection) or
-	// contain a number of MetricFamily protobufs, some of which might be
-	// incomplete, and some might be missing altogether. The returned error
-	// (which might be a MultiError) explains the details. In scenarios
-	// where complete collection is critical, the returned MetricFamily
-	// protobufs should be disregarded if the returned error is non-nil.
+	// of uniquely named MetricFamily protobufs. Gather ensures that the
+	// returned slice is valid and self-consistent so that it can be used
+	// for valid exposition. As an exception to the strict consistency
+	// requirements described for metric.Desc, Gather will tolerate
+	// different sets of label names for metrics of the same metric family.
+	//
+	// Even if an error occurs, Gather attempts to gather as many metrics as
+	// possible. Hence, if a non-nil error is returned, the returned
+	// MetricFamily slice could be nil (in case of a fatal error that
+	// prevented any meaningful metric collection) or contain a number of
+	// MetricFamily protobufs, some of which might be incomplete, and some
+	// might be missing altogether. The returned error (which might be a
+	// MultiError) explains the details. Note that this is mostly useful for
+	// debugging purposes. If the gathered protobufs are to be used for
+	// exposition in actual monitoring, it is almost always better to not
+	// expose an incomplete result and instead disregard the returned
+	// MetricFamily protobufs in case the returned error is non-nil.
 	Gather() ([]*dto.MetricFamily, error)
 }
 
@@ -201,6 +225,13 @@ func (errs MultiError) Error() string {
 	return buf.String()
 }
 
+// Append appends the provided error if it is not nil.
+func (errs *MultiError) Append(err error) {
+	if err != nil {
+		*errs = append(*errs, err)
+	}
+}
+
 // MaybeUnwrap returns nil if len(errs) is 0. It returns the first and only
 // contained error as error if len(errs is 1). In all other cases, it returns
 // the MultiError directly. This is helpful for returning a MultiError in a way
@@ -225,6 +256,7 @@ type Registry struct {
 	collectorsByID        map[uint64]Collector // ID is a hash of the descIDs.
 	descIDs               map[uint64]struct{}
 	dimHashesByName       map[string]uint64
+	uncheckedCollectors   []Collector
 	pedanticChecksEnabled bool
 }
 
@@ -242,7 +274,12 @@ func (r *Registry) Register(c Collector) error {
 		close(descChan)
 	}()
 	r.mtx.Lock()
-	defer r.mtx.Unlock()
+	defer func() {
+		// Drain channel in case of premature return to not leak a goroutine.
+		for range descChan {
+		}
+		r.mtx.Unlock()
+	}()
 	// Conduct various tests...
 	for desc := range descChan {
 
@@ -282,14 +319,23 @@ func (r *Registry) Register(c Collector) error {
 			}
 		}
 	}
-	// Did anything happen at all?
+	// A Collector yielding no Desc at all is considered unchecked.
 	if len(newDescIDs) == 0 {
-		return errors.New("collector has no descriptors")
+		r.uncheckedCollectors = append(r.uncheckedCollectors, c)
+		return nil
 	}
 	if existing, exists := r.collectorsByID[collectorID]; exists {
-		return AlreadyRegisteredError{
-			ExistingCollector: existing,
-			NewCollector:      c,
+		switch e := existing.(type) {
+		case *wrappingCollector:
+			return AlreadyRegisteredError{
+				ExistingCollector: e.unwrapRecursively(),
+				NewCollector:      c,
+			}
+		default:
+			return AlreadyRegisteredError{
+				ExistingCollector: e,
+				NewCollector:      c,
+			}
 		}
 	}
 	// If the collectorID is new, but at least one of the descs existed
@@ -358,31 +404,25 @@ func (r *Registry) MustRegister(cs ...Collector) {
 // Gather implements Gatherer.
 func (r *Registry) Gather() ([]*dto.MetricFamily, error) {
 	var (
-		metricChan        = make(chan Metric, capMetricChan)
-		metricHashes      = map[uint64]struct{}{}
-		dimHashes         = map[string]uint64{}
-		wg                sync.WaitGroup
-		errs              MultiError          // The collected errors to return in the end.
-		registeredDescIDs map[uint64]struct{} // Only used for pedantic checks
+		checkedMetricChan   = make(chan Metric, capMetricChan)
+		uncheckedMetricChan = make(chan Metric, capMetricChan)
+		metricHashes        = map[uint64]struct{}{}
+		wg                  sync.WaitGroup
+		errs                MultiError          // The collected errors to return in the end.
+		registeredDescIDs   map[uint64]struct{} // Only used for pedantic checks
 	)
 
 	r.mtx.RLock()
+	goroutineBudget := len(r.collectorsByID) + len(r.uncheckedCollectors)
 	metricFamiliesByName := make(map[string]*dto.MetricFamily, len(r.dimHashesByName))
-
-	// Scatter.
-	// (Collectors could be complex and slow, so we call them all at once.)
-	wg.Add(len(r.collectorsByID))
-	go func() {
-		wg.Wait()
-		close(metricChan)
-	}()
+	checkedCollectors := make(chan Collector, len(r.collectorsByID))
+	uncheckedCollectors := make(chan Collector, len(r.uncheckedCollectors))
 	for _, collector := range r.collectorsByID {
-		go func(collector Collector) {
-			defer wg.Done()
-			collector.Collect(metricChan)
-		}(collector)
+		checkedCollectors <- collector
+	}
+	for _, collector := range r.uncheckedCollectors {
+		uncheckedCollectors <- collector
 	}
-
 	// In case pedantic checks are enabled, we have to copy the map before
 	// giving up the RLock.
 	if r.pedanticChecksEnabled {
@@ -391,133 +431,264 @@ func (r *Registry) Gather() ([]*dto.MetricFamily, error) {
 			registeredDescIDs[id] = struct{}{}
 		}
 	}
-
 	r.mtx.RUnlock()
 
-	// Drain metricChan in case of premature return.
+	wg.Add(goroutineBudget)
+
+	collectWorker := func() {
+		for {
+			select {
+			case collector := <-checkedCollectors:
+				collector.Collect(checkedMetricChan)
+			case collector := <-uncheckedCollectors:
+				collector.Collect(uncheckedMetricChan)
+			default:
+				return
+			}
+			wg.Done()
+		}
+	}
+
+	// Start the first worker now to make sure at least one is running.
+	go collectWorker()
+	goroutineBudget--
+
+	// Close checkedMetricChan and uncheckedMetricChan once all collectors
+	// are collected.
+	go func() {
+		wg.Wait()
+		close(checkedMetricChan)
+		close(uncheckedMetricChan)
+	}()
+
+	// Drain checkedMetricChan and uncheckedMetricChan in case of premature return.
 	defer func() {
-		for range metricChan {
+		if checkedMetricChan != nil {
+			for range checkedMetricChan {
+			}
+		}
+		if uncheckedMetricChan != nil {
+			for range uncheckedMetricChan {
+			}
 		}
 	}()
 
-	// Gather.
-	for metric := range metricChan {
-		// This could be done concurrently, too, but it required locking
-		// of metricFamiliesByName (and of metricHashes if checks are
-		// enabled). Most likely not worth it.
-		desc := metric.Desc()
-		dtoMetric := &dto.Metric{}
-		if err := metric.Write(dtoMetric); err != nil {
-			errs = append(errs, fmt.Errorf(
-				"error collecting metric %v: %s", desc, err,
+	// Copy the channel references so we can nil them out later to remove
+	// them from the select statements below.
+	cmc := checkedMetricChan
+	umc := uncheckedMetricChan
+
+	for {
+		select {
+		case metric, ok := <-cmc:
+			if !ok {
+				cmc = nil
+				break
+			}
+			errs.Append(processMetric(
+				metric, metricFamiliesByName,
+				metricHashes,
+				registeredDescIDs,
 			))
-			continue
+		case metric, ok := <-umc:
+			if !ok {
+				umc = nil
+				break
+			}
+			errs.Append(processMetric(
+				metric, metricFamiliesByName,
+				metricHashes,
+				nil,
+			))
+		default:
+			if goroutineBudget <= 0 || len(checkedCollectors)+len(uncheckedCollectors) == 0 {
+				// All collectors are already being worked on or
+				// we have already as many goroutines started as
+				// there are collectors. Do the same as above,
+				// just without the default.
+				select {
+				case metric, ok := <-cmc:
+					if !ok {
+						cmc = nil
+						break
+					}
+					errs.Append(processMetric(
+						metric, metricFamiliesByName,
+						metricHashes,
+						registeredDescIDs,
+					))
+				case metric, ok := <-umc:
+					if !ok {
+						umc = nil
+						break
+					}
+					errs.Append(processMetric(
+						metric, metricFamiliesByName,
+						metricHashes,
+						nil,
+					))
+				}
+				break
+			}
+			// Start more workers.
+			go collectWorker()
+			goroutineBudget--
+			runtime.Gosched()
 		}
-		metricFamily, ok := metricFamiliesByName[desc.fqName]
-		if ok {
-			if metricFamily.GetHelp() != desc.help {
-				errs = append(errs, fmt.Errorf(
-					"collected metric %s %s has help %q but should have %q",
-					desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(),
-				))
-				continue
-			}
-			// TODO(beorn7): Simplify switch once Desc has type.
-			switch metricFamily.GetType() {
-			case dto.MetricType_COUNTER:
-				if dtoMetric.Counter == nil {
-					errs = append(errs, fmt.Errorf(
-						"collected metric %s %s should be a Counter",
-						desc.fqName, dtoMetric,
-					))
-					continue
-				}
-			case dto.MetricType_GAUGE:
-				if dtoMetric.Gauge == nil {
-					errs = append(errs, fmt.Errorf(
-						"collected metric %s %s should be a Gauge",
-						desc.fqName, dtoMetric,
-					))
-					continue
-				}
-			case dto.MetricType_SUMMARY:
-				if dtoMetric.Summary == nil {
-					errs = append(errs, fmt.Errorf(
-						"collected metric %s %s should be a Summary",
-						desc.fqName, dtoMetric,
-					))
-					continue
-				}
-			case dto.MetricType_UNTYPED:
-				if dtoMetric.Untyped == nil {
-					errs = append(errs, fmt.Errorf(
-						"collected metric %s %s should be Untyped",
-						desc.fqName, dtoMetric,
-					))
-					continue
-				}
-			case dto.MetricType_HISTOGRAM:
-				if dtoMetric.Histogram == nil {
-					errs = append(errs, fmt.Errorf(
-						"collected metric %s %s should be a Histogram",
-						desc.fqName, dtoMetric,
-					))
-					continue
-				}
-			default:
-				panic("encountered MetricFamily with invalid type")
-			}
-		} else {
-			metricFamily = &dto.MetricFamily{}
-			metricFamily.Name = proto.String(desc.fqName)
-			metricFamily.Help = proto.String(desc.help)
-			// TODO(beorn7): Simplify switch once Desc has type.
-			switch {
-			case dtoMetric.Gauge != nil:
-				metricFamily.Type = dto.MetricType_GAUGE.Enum()
-			case dtoMetric.Counter != nil:
-				metricFamily.Type = dto.MetricType_COUNTER.Enum()
-			case dtoMetric.Summary != nil:
-				metricFamily.Type = dto.MetricType_SUMMARY.Enum()
-			case dtoMetric.Untyped != nil:
-				metricFamily.Type = dto.MetricType_UNTYPED.Enum()
-			case dtoMetric.Histogram != nil:
-				metricFamily.Type = dto.MetricType_HISTOGRAM.Enum()
-			default:
-				errs = append(errs, fmt.Errorf(
-					"empty metric collected: %s", dtoMetric,
-				))
-				continue
-			}
-			metricFamiliesByName[desc.fqName] = metricFamily
+		// Once both checkedMetricChan and uncheckdMetricChan are closed
+		// and drained, the contraption above will nil out cmc and umc,
+		// and then we can leave the collect loop here.
+		if cmc == nil && umc == nil {
+			break
 		}
-		if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes, dimHashes); err != nil {
-			errs = append(errs, err)
-			continue
-		}
-		if r.pedanticChecksEnabled {
-			// Is the desc registered at all?
-			if _, exist := registeredDescIDs[desc.id]; !exist {
-				errs = append(errs, fmt.Errorf(
-					"collected metric %s %s with unregistered descriptor %s",
-					metricFamily.GetName(), dtoMetric, desc,
-				))
-				continue
-			}
-			if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil {
-				errs = append(errs, err)
-				continue
-			}
-		}
-		metricFamily.Metric = append(metricFamily.Metric, dtoMetric)
 	}
-	return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
+	return internal.NormalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
+}
+
+// WriteToTextfile calls Gather on the provided Gatherer, encodes the result in the
+// Prometheus text format, and writes it to a temporary file. Upon success, the
+// temporary file is renamed to the provided filename.
+//
+// This is intended for use with the textfile collector of the node exporter.
+// Note that the node exporter expects the filename to be suffixed with ".prom".
+func WriteToTextfile(filename string, g Gatherer) error {
+	tmp, err := ioutil.TempFile(filepath.Dir(filename), filepath.Base(filename))
+	if err != nil {
+		return err
+	}
+	defer os.Remove(tmp.Name())
+
+	mfs, err := g.Gather()
+	if err != nil {
+		return err
+	}
+	for _, mf := range mfs {
+		if _, err := expfmt.MetricFamilyToText(tmp, mf); err != nil {
+			return err
+		}
+	}
+	if err := tmp.Close(); err != nil {
+		return err
+	}
+
+	if err := os.Chmod(tmp.Name(), 0644); err != nil {
+		return err
+	}
+	return os.Rename(tmp.Name(), filename)
+}
+
+// processMetric is an internal helper method only used by the Gather method.
+func processMetric(
+	metric Metric,
+	metricFamiliesByName map[string]*dto.MetricFamily,
+	metricHashes map[uint64]struct{},
+	registeredDescIDs map[uint64]struct{},
+) error {
+	desc := metric.Desc()
+	// Wrapped metrics collected by an unchecked Collector can have an
+	// invalid Desc.
+	if desc.err != nil {
+		return desc.err
+	}
+	dtoMetric := &dto.Metric{}
+	if err := metric.Write(dtoMetric); err != nil {
+		return fmt.Errorf("error collecting metric %v: %s", desc, err)
+	}
+	metricFamily, ok := metricFamiliesByName[desc.fqName]
+	if ok { // Existing name.
+		if metricFamily.GetHelp() != desc.help {
+			return fmt.Errorf(
+				"collected metric %s %s has help %q but should have %q",
+				desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(),
+			)
+		}
+		// TODO(beorn7): Simplify switch once Desc has type.
+		switch metricFamily.GetType() {
+		case dto.MetricType_COUNTER:
+			if dtoMetric.Counter == nil {
+				return fmt.Errorf(
+					"collected metric %s %s should be a Counter",
+					desc.fqName, dtoMetric,
+				)
+			}
+		case dto.MetricType_GAUGE:
+			if dtoMetric.Gauge == nil {
+				return fmt.Errorf(
+					"collected metric %s %s should be a Gauge",
+					desc.fqName, dtoMetric,
+				)
+			}
+		case dto.MetricType_SUMMARY:
+			if dtoMetric.Summary == nil {
+				return fmt.Errorf(
+					"collected metric %s %s should be a Summary",
+					desc.fqName, dtoMetric,
+				)
+			}
+		case dto.MetricType_UNTYPED:
+			if dtoMetric.Untyped == nil {
+				return fmt.Errorf(
+					"collected metric %s %s should be Untyped",
+					desc.fqName, dtoMetric,
+				)
+			}
+		case dto.MetricType_HISTOGRAM:
+			if dtoMetric.Histogram == nil {
+				return fmt.Errorf(
+					"collected metric %s %s should be a Histogram",
+					desc.fqName, dtoMetric,
+				)
+			}
+		default:
+			panic("encountered MetricFamily with invalid type")
+		}
+	} else { // New name.
+		metricFamily = &dto.MetricFamily{}
+		metricFamily.Name = proto.String(desc.fqName)
+		metricFamily.Help = proto.String(desc.help)
+		// TODO(beorn7): Simplify switch once Desc has type.
+		switch {
+		case dtoMetric.Gauge != nil:
+			metricFamily.Type = dto.MetricType_GAUGE.Enum()
+		case dtoMetric.Counter != nil:
+			metricFamily.Type = dto.MetricType_COUNTER.Enum()
+		case dtoMetric.Summary != nil:
+			metricFamily.Type = dto.MetricType_SUMMARY.Enum()
+		case dtoMetric.Untyped != nil:
+			metricFamily.Type = dto.MetricType_UNTYPED.Enum()
+		case dtoMetric.Histogram != nil:
+			metricFamily.Type = dto.MetricType_HISTOGRAM.Enum()
+		default:
+			return fmt.Errorf("empty metric collected: %s", dtoMetric)
+		}
+		if err := checkSuffixCollisions(metricFamily, metricFamiliesByName); err != nil {
+			return err
+		}
+		metricFamiliesByName[desc.fqName] = metricFamily
+	}
+	if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes); err != nil {
+		return err
+	}
+	if registeredDescIDs != nil {
+		// Is the desc registered at all?
+		if _, exist := registeredDescIDs[desc.id]; !exist {
+			return fmt.Errorf(
+				"collected metric %s %s with unregistered descriptor %s",
+				metricFamily.GetName(), dtoMetric, desc,
+			)
+		}
+		if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil {
+			return err
+		}
+	}
+	metricFamily.Metric = append(metricFamily.Metric, dtoMetric)
+	return nil
 }
 
 // Gatherers is a slice of Gatherer instances that implements the Gatherer
 // interface itself. Its Gather method calls Gather on all Gatherers in the
 // slice in order and returns the merged results. Errors returned from the
-// Gather calles are all returned in a flattened MultiError. Duplicate and
+// Gather calls are all returned in a flattened MultiError. Duplicate and
 // inconsistent Metrics are skipped (first occurrence in slice order wins) and
 // reported in the returned error.
 //
@@ -537,7 +708,6 @@ func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) {
 	var (
 		metricFamiliesByName = map[string]*dto.MetricFamily{}
 		metricHashes         = map[uint64]struct{}{}
-		dimHashes            = map[string]uint64{}
 		errs                 MultiError // The collected errors to return in the end.
 	)
 
@@ -574,10 +744,14 @@ func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) {
 				existingMF.Name = mf.Name
 				existingMF.Help = mf.Help
 				existingMF.Type = mf.Type
+				if err := checkSuffixCollisions(existingMF, metricFamiliesByName); err != nil {
+					errs = append(errs, err)
+					continue
+				}
 				metricFamiliesByName[mf.GetName()] = existingMF
 			}
 			for _, m := range mf.Metric {
-				if err := checkMetricConsistency(existingMF, m, metricHashes, dimHashes); err != nil {
+				if err := checkMetricConsistency(existingMF, m, metricHashes); err != nil {
 					errs = append(errs, err)
 					continue
 				}
@@ -585,88 +759,80 @@ func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) {
 			}
 		}
 	}
-	return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
+	return internal.NormalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
 }
 
-// metricSorter is a sortable slice of *dto.Metric.
-type metricSorter []*dto.Metric
-
-func (s metricSorter) Len() int {
-	return len(s)
-}
-
-func (s metricSorter) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
-}
-
-func (s metricSorter) Less(i, j int) bool {
-	if len(s[i].Label) != len(s[j].Label) {
-		// This should not happen. The metrics are
-		// inconsistent. However, we have to deal with the fact, as
-		// people might use custom collectors or metric family injection
-		// to create inconsistent metrics. So let's simply compare the
-		// number of labels in this case. That will still yield
-		// reproducible sorting.
-		return len(s[i].Label) < len(s[j].Label)
+// checkSuffixCollisions checks for collisions with the “magic” suffixes the
+// Prometheus text format and the internal metric representation of the
+// Prometheus server add while flattening Summaries and Histograms.
+func checkSuffixCollisions(mf *dto.MetricFamily, mfs map[string]*dto.MetricFamily) error {
+	var (
+		newName              = mf.GetName()
+		newType              = mf.GetType()
+		newNameWithoutSuffix = ""
+	)
+	switch {
+	case strings.HasSuffix(newName, "_count"):
+		newNameWithoutSuffix = newName[:len(newName)-6]
+	case strings.HasSuffix(newName, "_sum"):
+		newNameWithoutSuffix = newName[:len(newName)-4]
+	case strings.HasSuffix(newName, "_bucket"):
+		newNameWithoutSuffix = newName[:len(newName)-7]
 	}
-	for n, lp := range s[i].Label {
-		vi := lp.GetValue()
-		vj := s[j].Label[n].GetValue()
-		if vi != vj {
-			return vi < vj
+	if newNameWithoutSuffix != "" {
+		if existingMF, ok := mfs[newNameWithoutSuffix]; ok {
+			switch existingMF.GetType() {
+			case dto.MetricType_SUMMARY:
+				if !strings.HasSuffix(newName, "_bucket") {
+					return fmt.Errorf(
+						"collected metric named %q collides with previously collected summary named %q",
+						newName, newNameWithoutSuffix,
+					)
+				}
+			case dto.MetricType_HISTOGRAM:
+				return fmt.Errorf(
+					"collected metric named %q collides with previously collected histogram named %q",
+					newName, newNameWithoutSuffix,
+				)
+			}
 		}
 	}
-
-	// We should never arrive here. Multiple metrics with the same
-	// label set in the same scrape will lead to undefined ingestion
-	// behavior. However, as above, we have to provide stable sorting
-	// here, even for inconsistent metrics. So sort equal metrics
-	// by their timestamp, with missing timestamps (implying "now")
-	// coming last.
-	if s[i].TimestampMs == nil {
-		return false
-	}
-	if s[j].TimestampMs == nil {
-		return true
-	}
-	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
-}
-
-// normalizeMetricFamilies returns a MetricFamily slice with empty
-// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
-// the slice, with the contained Metrics sorted within each MetricFamily.
-func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
-	for _, mf := range metricFamiliesByName {
-		sort.Sort(metricSorter(mf.Metric))
-	}
-	names := make([]string, 0, len(metricFamiliesByName))
-	for name, mf := range metricFamiliesByName {
-		if len(mf.Metric) > 0 {
-			names = append(names, name)
+	if newType == dto.MetricType_SUMMARY || newType == dto.MetricType_HISTOGRAM {
+		if _, ok := mfs[newName+"_count"]; ok {
+			return fmt.Errorf(
+				"collected histogram or summary named %q collides with previously collected metric named %q",
+				newName, newName+"_count",
+			)
+		}
+		if _, ok := mfs[newName+"_sum"]; ok {
+			return fmt.Errorf(
+				"collected histogram or summary named %q collides with previously collected metric named %q",
+				newName, newName+"_sum",
+			)
 		}
 	}
-	sort.Strings(names)
-	result := make([]*dto.MetricFamily, 0, len(names))
-	for _, name := range names {
-		result = append(result, metricFamiliesByName[name])
+	if newType == dto.MetricType_HISTOGRAM {
+		if _, ok := mfs[newName+"_bucket"]; ok {
+			return fmt.Errorf(
+				"collected histogram named %q collides with previously collected metric named %q",
+				newName, newName+"_bucket",
+			)
+		}
 	}
-	return result
+	return nil
 }
 
 // checkMetricConsistency checks if the provided Metric is consistent with the
-// provided MetricFamily. It also hashed the Metric labels and the MetricFamily
-// name. If the resulting hash is alread in the provided metricHashes, an error
-// is returned. If not, it is added to metricHashes. The provided dimHashes maps
-// MetricFamily names to their dimHash (hashed sorted label names). If dimHashes
-// doesn't yet contain a hash for the provided MetricFamily, it is
-// added. Otherwise, an error is returned if the existing dimHashes in not equal
-// the calculated dimHash.
+// provided MetricFamily. It also hashes the Metric labels and the MetricFamily
+// name. If the resulting hash is already in the provided metricHashes, an error
+// is returned. If not, it is added to metricHashes.
 func checkMetricConsistency(
 	metricFamily *dto.MetricFamily,
 	dtoMetric *dto.Metric,
 	metricHashes map[uint64]struct{},
-	dimHashes map[string]uint64,
 ) error {
+	name := metricFamily.GetName()
+
 	// Type consistency with metric family.
 	if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil ||
 		metricFamily.GetType() == dto.MetricType_COUNTER && dtoMetric.Counter == nil ||
@@ -674,41 +840,65 @@ func checkMetricConsistency(
 		metricFamily.GetType() == dto.MetricType_HISTOGRAM && dtoMetric.Histogram == nil ||
 		metricFamily.GetType() == dto.MetricType_UNTYPED && dtoMetric.Untyped == nil {
 		return fmt.Errorf(
-			"collected metric %s %s is not a %s",
-			metricFamily.GetName(), dtoMetric, metricFamily.GetType(),
+			"collected metric %q { %s} is not a %s",
+			name, dtoMetric, metricFamily.GetType(),
 		)
 	}
 
-	// Is the metric unique (i.e. no other metric with the same name and the same label values)?
+	previousLabelName := ""
+	for _, labelPair := range dtoMetric.GetLabel() {
+		labelName := labelPair.GetName()
+		if labelName == previousLabelName {
+			return fmt.Errorf(
+				"collected metric %q { %s} has two or more labels with the same name: %s",
+				name, dtoMetric, labelName,
+			)
+		}
+		if !checkLabelName(labelName) {
+			return fmt.Errorf(
+				"collected metric %q { %s} has a label with an invalid name: %s",
+				name, dtoMetric, labelName,
+			)
+		}
+		if dtoMetric.Summary != nil && labelName == quantileLabel {
+			return fmt.Errorf(
+				"collected metric %q { %s} must not have an explicit %q label",
+				name, dtoMetric, quantileLabel,
+			)
+		}
+		if !utf8.ValidString(labelPair.GetValue()) {
+			return fmt.Errorf(
+				"collected metric %q { %s} has a label named %q whose value is not utf8: %#v",
+				name, dtoMetric, labelName, labelPair.GetValue())
+		}
+		previousLabelName = labelName
+	}
+
+	// Is the metric unique (i.e. no other metric with the same name and the same labels)?
 	h := hashNew()
-	h = hashAdd(h, metricFamily.GetName())
+	h = hashAdd(h, name)
 	h = hashAddByte(h, separatorByte)
-	dh := hashNew()
 	// Make sure label pairs are sorted. We depend on it for the consistency
 	// check.
-	sort.Sort(LabelPairSorter(dtoMetric.Label))
+	if !sort.IsSorted(labelPairSorter(dtoMetric.Label)) {
+		// We cannot sort dtoMetric.Label in place as it is immutable by contract.
+		copiedLabels := make([]*dto.LabelPair, len(dtoMetric.Label))
+		copy(copiedLabels, dtoMetric.Label)
+		sort.Sort(labelPairSorter(copiedLabels))
+		dtoMetric.Label = copiedLabels
+	}
 	for _, lp := range dtoMetric.Label {
+		h = hashAdd(h, lp.GetName())
+		h = hashAddByte(h, separatorByte)
 		h = hashAdd(h, lp.GetValue())
 		h = hashAddByte(h, separatorByte)
-		dh = hashAdd(dh, lp.GetName())
-		dh = hashAddByte(dh, separatorByte)
 	}
 	if _, exists := metricHashes[h]; exists {
 		return fmt.Errorf(
-			"collected metric %s %s was collected before with the same name and label values",
-			metricFamily.GetName(), dtoMetric,
+			"collected metric %q { %s} was collected before with the same name and label values",
+			name, dtoMetric,
 		)
 	}
-	if dimHash, ok := dimHashes[metricFamily.GetName()]; ok {
-		if dimHash != dh {
-			return fmt.Errorf(
-				"collected metric %s %s has label dimensions inconsistent with previously collected metrics in the same metric family",
-				metricFamily.GetName(), dtoMetric,
-			)
-		}
-	} else {
-		dimHashes[metricFamily.GetName()] = dh
-	}
 	metricHashes[h] = struct{}{}
 	return nil
 }
@@ -727,8 +917,8 @@ func checkDescConsistency(
 	}
 
 	// Is the desc consistent with the content of the metric?
-	lpsFromDesc := make([]*dto.LabelPair, 0, len(dtoMetric.Label))
-	lpsFromDesc = append(lpsFromDesc, desc.constLabelPairs...)
+	lpsFromDesc := make([]*dto.LabelPair, len(desc.constLabelPairs), len(dtoMetric.Label))
+	copy(lpsFromDesc, desc.constLabelPairs)
 	for _, l := range desc.variableLabels {
 		lpsFromDesc = append(lpsFromDesc, &dto.LabelPair{
 			Name: proto.String(l),
@@ -740,7 +930,7 @@ func checkDescConsistency(
 			metricFamily.GetName(), dtoMetric, desc,
 		)
 	}
-	sort.Sort(LabelPairSorter(lpsFromDesc))
+	sort.Sort(labelPairSorter(lpsFromDesc))
 	for i, lpFromDesc := range lpsFromDesc {
 		lpFromMetric := dtoMetric.Label[i]
 		if lpFromDesc.GetName() != lpFromMetric.GetName() ||

vendor/github.com/prometheus/client_golang/prometheus/summary.go

@@ -16,8 +16,10 @@ package prometheus
 import (
 	"fmt"
 	"math"
+	"runtime"
 	"sort"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/beorn7/perks/quantile"
@@ -36,7 +38,10 @@ const quantileLabel = "quantile"
 //
 // A typical use-case is the observation of request latencies. By default, a
 // Summary provides the median, the 90th and the 99th percentile of the latency
-// as rank estimations.
+// as rank estimations. However, the default behavior will change in the
+// upcoming v1.0.0 of the library. There will be no rank estimations at all by
+// default. For a sane transition, it is recommended to set the desired rank
+// estimations explicitly.
 //
 // Note that the rank estimations cannot be aggregated in a meaningful way with
 // the Prometheus query language (i.e. you cannot average or add them). If you
@@ -53,16 +58,8 @@ type Summary interface {
 	Observe(float64)
 }
 
-// DefObjectives are the default Summary quantile values.
-//
-// Deprecated: DefObjectives will not be used as the default objectives in
-// v0.10 of the library. The default Summary will have no quantiles then.
-var (
-	DefObjectives = map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}
-
-	errQuantileLabelNotAllowed = fmt.Errorf(
-		"%q is not allowed as label name in summaries", quantileLabel,
-	)
+var errQuantileLabelNotAllowed = fmt.Errorf(
+	"%q is not allowed as label name in summaries", quantileLabel,
 )
 
 // Default values for SummaryOpts.
@@ -78,8 +75,10 @@ const (
 )
 
 // SummaryOpts bundles the options for creating a Summary metric. It is
-// mandatory to set Name and Help to a non-empty string. All other fields are
-// optional and can safely be left at their zero value.
+// mandatory to set Name to a non-empty string. While all other fields are
+// optional and can safely be left at their zero value, it is recommended to set
+// a help string and to explicitly set the Objectives field to the desired value
+// as the default value will change in the upcoming v1.0.0 of the library.
 type SummaryOpts struct {
 	// Namespace, Subsystem, and Name are components of the fully-qualified
 	// name of the Summary (created by joining these components with
@@ -90,41 +89,34 @@ type SummaryOpts struct {
 	Subsystem string
 	Name      string
 
-	// Help provides information about this Summary. Mandatory!
+	// Help provides information about this Summary.
 	//
 	// Metrics with the same fully-qualified name must have the same Help
 	// string.
 	Help string
 
-	// ConstLabels are used to attach fixed labels to this
-	// Summary. Summaries with the same fully-qualified name must have the
-	// same label names in their ConstLabels.
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
 	//
-	// Note that in most cases, labels have a value that varies during the
-	// lifetime of a process. Those labels are usually managed with a
-	// SummaryVec. ConstLabels serve only special purposes. One is for the
-	// special case where the value of a label does not change during the
-	// lifetime of a process, e.g. if the revision of the running binary is
-	// put into a label. Another, more advanced purpose is if more than one
-	// Collector needs to collect Summaries with the same fully-qualified
-	// name. In that case, those Summaries must differ in the values of
-	// their ConstLabels. See the Collector examples.
+	// Due to the way a Summary is represented in the Prometheus text format
+	// and how it is handled by the Prometheus server internally, “quantile”
+	// is an illegal label name. Construction of a Summary or SummaryVec
+	// will panic if this label name is used in ConstLabels.
 	//
-	// If the value of a label never changes (not even between binaries),
-	// that label most likely should not be a label at all (but part of the
-	// metric name).
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
 	ConstLabels Labels
 
 	// Objectives defines the quantile rank estimates with their respective
 	// absolute error. If Objectives[q] = e, then the value reported for q
 	// will be the φ-quantile value for some φ between q-e and q+e.  The
-	// default value is DefObjectives. It is used if Objectives is left at
-	// its zero value (i.e. nil). To create a Summary without Objectives,
-	// set it to an empty map (i.e. map[float64]float64{}).
-	//
-	// Deprecated: Note that the current value of DefObjectives is
-	// deprecated. It will be replaced by an empty map in v0.10 of the
-	// library. Please explicitly set Objectives to the desired value.
+	// default value is an empty map, resulting in a summary without
+	// quantiles.
 	Objectives map[float64]float64
 
 	// MaxAge defines the duration for which an observation stays relevant
@@ -148,7 +140,7 @@ type SummaryOpts struct {
 	BufCap uint32
 }
 
-// Great fuck-up with the sliding-window decay algorithm... The Merge method of
+// Problem with the sliding-window decay algorithm... The Merge method of
 // perk/quantile is actually not working as advertised - and it might be
 // unfixable, as the underlying algorithm is apparently not capable of merging
 // summaries in the first place. To avoid using Merge, we are currently adding
@@ -178,7 +170,7 @@ func NewSummary(opts SummaryOpts) Summary {
 
 func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 	if len(desc.variableLabels) != len(labelValues) {
-		panic(errInconsistentCardinality)
+		panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, labelValues))
 	}
 
 	for _, n := range desc.variableLabels {
@@ -193,7 +185,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 	}
 
 	if opts.Objectives == nil {
-		opts.Objectives = DefObjectives
+		opts.Objectives = map[float64]float64{}
 	}
 
 	if opts.MaxAge < 0 {
@@ -211,6 +203,17 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 		opts.BufCap = DefBufCap
 	}
 
+	if len(opts.Objectives) == 0 {
+		// Use the lock-free implementation of a Summary without objectives.
+		s := &noObjectivesSummary{
+			desc:       desc,
+			labelPairs: makeLabelPairs(desc, labelValues),
+			counts:     [2]*summaryCounts{&summaryCounts{}, &summaryCounts{}},
+		}
+		s.init(s) // Init self-collection.
+		return s
+	}
+
 	s := &summary{
 		desc: desc,
 
@@ -379,6 +382,116 @@ func (s *summary) swapBufs(now time.Time) {
 	}
 }
 
+type summaryCounts struct {
+	// sumBits contains the bits of the float64 representing the sum of all
+	// observations. sumBits and count have to go first in the struct to
+	// guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	sumBits uint64
+	count   uint64
+}
+
+type noObjectivesSummary struct {
+	// countAndHotIdx enables lock-free writes with use of atomic updates.
+	// The most significant bit is the hot index [0 or 1] of the count field
+	// below. Observe calls update the hot one. All remaining bits count the
+	// number of Observe calls. Observe starts by incrementing this counter,
+	// and finish by incrementing the count field in the respective
+	// summaryCounts, as a marker for completion.
+	//
+	// Calls of the Write method (which are non-mutating reads from the
+	// perspective of the summary) swap the hot–cold under the writeMtx
+	// lock. A cooldown is awaited (while locked) by comparing the number of
+	// observations with the initiation count. Once they match, then the
+	// last observation on the now cool one has completed. All cool fields must
+	// be merged into the new hot before releasing writeMtx.
+
+	// Fields with atomic access first! See alignment constraint:
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	countAndHotIdx uint64
+
+	selfCollector
+	desc     *Desc
+	writeMtx sync.Mutex // Only used in the Write method.
+
+	// Two counts, one is "hot" for lock-free observations, the other is
+	// "cold" for writing out a dto.Metric. It has to be an array of
+	// pointers to guarantee 64bit alignment of the histogramCounts, see
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG.
+	counts [2]*summaryCounts
+
+	labelPairs []*dto.LabelPair
+}
+
+func (s *noObjectivesSummary) Desc() *Desc {
+	return s.desc
+}
+
+func (s *noObjectivesSummary) Observe(v float64) {
+	// We increment h.countAndHotIdx so that the counter in the lower
+	// 63 bits gets incremented. At the same time, we get the new value
+	// back, which we can use to find the currently-hot counts.
+	n := atomic.AddUint64(&s.countAndHotIdx, 1)
+	hotCounts := s.counts[n>>63]
+
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			break
+		}
+	}
+	// Increment count last as we take it as a signal that the observation
+	// is complete.
+	atomic.AddUint64(&hotCounts.count, 1)
+}
+
+func (s *noObjectivesSummary) Write(out *dto.Metric) error {
+	// For simplicity, we protect this whole method by a mutex. It is not in
+	// the hot path, i.e. Observe is called much more often than Write. The
+	// complication of making Write lock-free isn't worth it, if possible at
+	// all.
+	s.writeMtx.Lock()
+	defer s.writeMtx.Unlock()
+
+	// Adding 1<<63 switches the hot index (from 0 to 1 or from 1 to 0)
+	// without touching the count bits. See the struct comments for a full
+	// description of the algorithm.
+	n := atomic.AddUint64(&s.countAndHotIdx, 1<<63)
+	// count is contained unchanged in the lower 63 bits.
+	count := n & ((1 << 63) - 1)
+	// The most significant bit tells us which counts is hot. The complement
+	// is thus the cold one.
+	hotCounts := s.counts[n>>63]
+	coldCounts := s.counts[(^n)>>63]
+
+	// Await cooldown.
+	for count != atomic.LoadUint64(&coldCounts.count) {
+		runtime.Gosched() // Let observations get work done.
+	}
+
+	sum := &dto.Summary{
+		SampleCount: proto.Uint64(count),
+		SampleSum:   proto.Float64(math.Float64frombits(atomic.LoadUint64(&coldCounts.sumBits))),
+	}
+
+	out.Summary = sum
+	out.Label = s.labelPairs
+
+	// Finally add all the cold counts to the new hot counts and reset the cold counts.
+	atomic.AddUint64(&hotCounts.count, count)
+	atomic.StoreUint64(&coldCounts.count, 0)
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + sum.GetSampleSum())
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			atomic.StoreUint64(&coldCounts.sumBits, 0)
+			break
+		}
+	}
+	return nil
+}
+
 type quantSort []*dto.Quantile
 
 func (s quantSort) Len() int {
@@ -399,13 +512,21 @@ func (s quantSort) Less(i, j int) bool {
 // (e.g. HTTP request latencies, partitioned by status code and method). Create
 // instances with NewSummaryVec.
 type SummaryVec struct {
-	*MetricVec
+	*metricVec
 }
 
 // NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
+// partitioned by the given label names.
+//
+// Due to the way a Summary is represented in the Prometheus text format and how
+// it is handled by the Prometheus server internally, “quantile” is an illegal
+// label name. NewSummaryVec will panic if this label name is used.
 func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
+	for _, ln := range labelNames {
+		if ln == quantileLabel {
+			panic(errQuantileLabelNotAllowed)
+		}
+	}
 	desc := NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
 		opts.Help,
@@ -413,47 +534,116 @@ func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
 		opts.ConstLabels,
 	)
 	return &SummaryVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
 			return newSummary(desc, opts, lvs...)
 		}),
 	}
 }
 
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns a Summary and not a
-// Metric so that no type conversion is required.
-func (m *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Summary, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+// GetMetricWithLabelValues returns the Summary for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Summary is created.
+//
+// It is possible to call this method without using the returned Summary to only
+// create the new Summary but leave it at its starting value, a Summary without
+// any observations.
+//
+// Keeping the Summary for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Summary from the SummaryVec. In that case,
+// the Summary will still exist, but it will not be exported anymore, even if a
+// Summary with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
 	if metric != nil {
-		return metric.(Summary), err
+		return metric.(Observer), err
 	}
 	return nil, err
 }
 
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns a Summary and not a Metric so that no
-// type conversion is required.
-func (m *SummaryVec) GetMetricWith(labels Labels) (Summary, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
+// GetMetricWith returns the Summary for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Summary is created. Implications of
+// creating a Summary without using it and keeping the Summary for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *SummaryVec) GetMetricWith(labels Labels) (Observer, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
 	if metric != nil {
-		return metric.(Summary), err
+		return metric.(Observer), err
 	}
 	return nil, err
 }
 
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
 //     myVec.WithLabelValues("404", "GET").Observe(42.21)
-func (m *SummaryVec) WithLabelValues(lvs ...string) Summary {
-	return m.MetricVec.WithLabelValues(lvs...).(Summary)
+func (v *SummaryVec) WithLabelValues(lvs ...string) Observer {
+	s, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return s
 }
 
 // With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21)
-func (m *SummaryVec) With(labels Labels) Summary {
-	return m.MetricVec.With(labels).(Summary)
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (v *SummaryVec) With(labels Labels) Observer {
+	s, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return s
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the SummaryVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *SummaryVec) CurryWith(labels Labels) (ObserverVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &SummaryVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *SummaryVec) MustCurryWith(labels Labels) ObserverVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
 }
 
 type constSummary struct {
@@ -506,7 +696,7 @@ func (s *constSummary) Write(out *dto.Metric) error {
 //     map[float64]float64{0.5: 0.23, 0.99: 0.56}
 //
 // NewConstSummary returns an error if the length of labelValues is not
-// consistent with the variable labels in Desc.
+// consistent with the variable labels in Desc or if Desc is invalid.
 func NewConstSummary(
 	desc *Desc,
 	count uint64,
@@ -514,8 +704,11 @@ func NewConstSummary(
 	quantiles map[float64]float64,
 	labelValues ...string,
 ) (Metric, error) {
-	if len(desc.variableLabels) != len(labelValues) {
-		return nil, errInconsistentCardinality
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
+		return nil, err
 	}
 	return &constSummary{
 		desc:       desc,

vendor/github.com/prometheus/client_golang/prometheus/timer.go

@@ -15,32 +15,6 @@ package prometheus
 
 import "time"
 
-// Observer is the interface that wraps the Observe method, which is used by
-// Histogram and Summary to add observations.
-type Observer interface {
-	Observe(float64)
-}
-
-// The ObserverFunc type is an adapter to allow the use of ordinary
-// functions as Observers. If f is a function with the appropriate
-// signature, ObserverFunc(f) is an Observer that calls f.
-//
-// This adapter is usually used in connection with the Timer type, and there are
-// two general use cases:
-//
-// The most common one is to use a Gauge as the Observer for a Timer.
-// See the "Gauge" Timer example.
-//
-// The more advanced use case is to create a function that dynamically decides
-// which Observer to use for observing the duration. See the "Complex" Timer
-// example.
-type ObserverFunc func(float64)
-
-// Observe calls f(value). It implements Observer.
-func (f ObserverFunc) Observe(value float64) {
-	f(value)
-}
-
 // Timer is a helper type to time functions. Use NewTimer to create new
 // instances.
 type Timer struct {
@@ -65,10 +39,16 @@ func NewTimer(o Observer) *Timer {
 
 // ObserveDuration records the duration passed since the Timer was created with
 // NewTimer. It calls the Observe method of the Observer provided during
-// construction with the duration in seconds as an argument. ObserveDuration is
-// usually called with a defer statement.
-func (t *Timer) ObserveDuration() {
+// construction with the duration in seconds as an argument. The observed
+// duration is also returned. ObserveDuration is usually called with a defer
+// statement.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func (t *Timer) ObserveDuration() time.Duration {
+	d := time.Since(t.begin)
 	if t.observer != nil {
-		t.observer.Observe(time.Since(t.begin).Seconds())
+		t.observer.Observe(d.Seconds())
 	}
+	return d
 }

vendor/github.com/prometheus/client_golang/prometheus/untyped.go

@@ -13,113 +13,12 @@
 
 package prometheus
 
-// Untyped is a Metric that represents a single numerical value that can
-// arbitrarily go up and down.
-//
-// An Untyped metric works the same as a Gauge. The only difference is that to
-// no type information is implied.
-//
-// To create Untyped instances, use NewUntyped.
-//
-// Deprecated: The Untyped type is deprecated because it doesn't make sense in
-// direct instrumentation. If you need to mirror an external metric of unknown
-// type (usually while writing exporters), Use MustNewConstMetric to create an
-// untyped metric instance on the fly.
-type Untyped interface {
-	Metric
-	Collector
-
-	// Set sets the Untyped metric to an arbitrary value.
-	Set(float64)
-	// Inc increments the Untyped metric by 1.
-	Inc()
-	// Dec decrements the Untyped metric by 1.
-	Dec()
-	// Add adds the given value to the Untyped metric. (The value can be
-	// negative, resulting in a decrease.)
-	Add(float64)
-	// Sub subtracts the given value from the Untyped metric. (The value can
-	// be negative, resulting in an increase.)
-	Sub(float64)
-}
-
 // UntypedOpts is an alias for Opts. See there for doc comments.
 type UntypedOpts Opts
 
-// NewUntyped creates a new Untyped metric from the provided UntypedOpts.
-func NewUntyped(opts UntypedOpts) Untyped {
-	return newValue(NewDesc(
-		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
-		opts.Help,
-		nil,
-		opts.ConstLabels,
-	), UntypedValue, 0)
-}
-
-// UntypedVec is a Collector that bundles a set of Untyped metrics that all
-// share the same Desc, but have different values for their variable
-// labels. This is used if you want to count the same thing partitioned by
-// various dimensions. Create instances with NewUntypedVec.
-type UntypedVec struct {
-	*MetricVec
-}
-
-// NewUntypedVec creates a new UntypedVec based on the provided UntypedOpts and
-// partitioned by the given label names. At least one label name must be
-// provided.
-func NewUntypedVec(opts UntypedOpts, labelNames []string) *UntypedVec {
-	desc := NewDesc(
-		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
-		opts.Help,
-		labelNames,
-		opts.ConstLabels,
-	)
-	return &UntypedVec{
-		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
-			return newValue(desc, UntypedValue, 0, lvs...)
-		}),
-	}
-}
-
-// GetMetricWithLabelValues replaces the method of the same name in
-// MetricVec. The difference is that this method returns an Untyped and not a
-// Metric so that no type conversion is required.
-func (m *UntypedVec) GetMetricWithLabelValues(lvs ...string) (Untyped, error) {
-	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
-	if metric != nil {
-		return metric.(Untyped), err
-	}
-	return nil, err
-}
-
-// GetMetricWith replaces the method of the same name in MetricVec. The
-// difference is that this method returns an Untyped and not a Metric so that no
-// type conversion is required.
-func (m *UntypedVec) GetMetricWith(labels Labels) (Untyped, error) {
-	metric, err := m.MetricVec.GetMetricWith(labels)
-	if metric != nil {
-		return metric.(Untyped), err
-	}
-	return nil, err
-}
-
-// WithLabelValues works as GetMetricWithLabelValues, but panics where
-// GetMetricWithLabelValues would have returned an error. By not returning an
-// error, WithLabelValues allows shortcuts like
-//     myVec.WithLabelValues("404", "GET").Add(42)
-func (m *UntypedVec) WithLabelValues(lvs ...string) Untyped {
-	return m.MetricVec.WithLabelValues(lvs...).(Untyped)
-}
-
-// With works as GetMetricWith, but panics where GetMetricWithLabels would have
-// returned an error. By not returning an error, With allows shortcuts like
-//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
-func (m *UntypedVec) With(labels Labels) Untyped {
-	return m.MetricVec.With(labels).(Untyped)
-}
-
-// UntypedFunc is an Untyped whose value is determined at collect time by
-// calling a provided function.
+// UntypedFunc works like GaugeFunc but the collected metric is of type
+// "Untyped". UntypedFunc is useful to mirror an external metric of unknown
+// type.
 //
 // To create UntypedFunc instances, use NewUntypedFunc.
 type UntypedFunc interface {

vendor/github.com/prometheus/client_golang/prometheus/value.go

@@ -14,16 +14,12 @@
 package prometheus
 
 import (
-	"errors"
 	"fmt"
-	"math"
 	"sort"
-	"sync/atomic"
-	"time"
-
-	dto "github.com/prometheus/client_model/go"
 
 	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
 )
 
 // ValueType is an enumeration of metric types that represent a simple value.
@@ -37,81 +33,6 @@ const (
 	UntypedValue
 )
 
-var errInconsistentCardinality = errors.New("inconsistent label cardinality")
-
-// value is a generic metric for simple values. It implements Metric, Collector,
-// Counter, Gauge, and Untyped. Its effective type is determined by
-// ValueType. This is a low-level building block used by the library to back the
-// implementations of Counter, Gauge, and Untyped.
-type value struct {
-	// valBits contains the bits of the represented float64 value. It has
-	// to go first in the struct to guarantee alignment for atomic
-	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
-	valBits uint64
-
-	selfCollector
-
-	desc       *Desc
-	valType    ValueType
-	labelPairs []*dto.LabelPair
-}
-
-// newValue returns a newly allocated value with the given Desc, ValueType,
-// sample value and label values. It panics if the number of label
-// values is different from the number of variable labels in Desc.
-func newValue(desc *Desc, valueType ValueType, val float64, labelValues ...string) *value {
-	if len(labelValues) != len(desc.variableLabels) {
-		panic(errInconsistentCardinality)
-	}
-	result := &value{
-		desc:       desc,
-		valType:    valueType,
-		valBits:    math.Float64bits(val),
-		labelPairs: makeLabelPairs(desc, labelValues),
-	}
-	result.init(result)
-	return result
-}
-
-func (v *value) Desc() *Desc {
-	return v.desc
-}
-
-func (v *value) Set(val float64) {
-	atomic.StoreUint64(&v.valBits, math.Float64bits(val))
-}
-
-func (v *value) SetToCurrentTime() {
-	v.Set(float64(time.Now().UnixNano()) / 1e9)
-}
-
-func (v *value) Inc() {
-	v.Add(1)
-}
-
-func (v *value) Dec() {
-	v.Add(-1)
-}
-
-func (v *value) Add(val float64) {
-	for {
-		oldBits := atomic.LoadUint64(&v.valBits)
-		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
-		if atomic.CompareAndSwapUint64(&v.valBits, oldBits, newBits) {
-			return
-		}
-	}
-}
-
-func (v *value) Sub(val float64) {
-	v.Add(val * -1)
-}
-
-func (v *value) Write(out *dto.Metric) error {
-	val := math.Float64frombits(atomic.LoadUint64(&v.valBits))
-	return populateMetric(v.valType, val, v.labelPairs, out)
-}
-
 // valueFunc is a generic metric for simple values retrieved on collect time
 // from a function. It implements Metric and Collector. Its effective type is
 // determined by ValueType. This is a low-level building block used by the
@@ -156,10 +77,14 @@ func (v *valueFunc) Write(out *dto.Metric) error {
 // operations. However, when implementing custom Collectors, it is useful as a
 // throw-away metric that is generated on the fly to send it to Prometheus in
 // the Collect method. NewConstMetric returns an error if the length of
-// labelValues is not consistent with the variable labels in Desc.
+// labelValues is not consistent with the variable labels in Desc or if Desc is
+// invalid.
 func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) {
-	if len(desc.variableLabels) != len(labelValues) {
-		return nil, errInconsistentCardinality
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
+		return nil, err
 	}
 	return &constMetric{
 		desc:       desc,
@@ -231,9 +156,7 @@ func makeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
 			Value: proto.String(labelValues[i]),
 		})
 	}
-	for _, lp := range desc.constLabelPairs {
-		labelPairs = append(labelPairs, lp)
-	}
-	sort.Sort(LabelPairSorter(labelPairs))
+	labelPairs = append(labelPairs, desc.constLabelPairs...)
+	sort.Sort(labelPairSorter(labelPairs))
 	return labelPairs
 }

vendor/github.com/prometheus/client_golang/prometheus/vec.go

@@ -20,33 +20,180 @@ import (
 	"github.com/prometheus/common/model"
 )
 
-// MetricVec is a Collector to bundle metrics of the same name that
-// differ in their label values. MetricVec is usually not used directly but as a
-// building block for implementations of vectors of a given metric
-// type. GaugeVec, CounterVec, SummaryVec, and UntypedVec are examples already
-// provided in this package.
-type MetricVec struct {
-	mtx      sync.RWMutex // Protects the children.
-	children map[uint64][]metricWithLabelValues
-	desc     *Desc
+// metricVec is a Collector to bundle metrics of the same name that differ in
+// their label values. metricVec is not used directly (and therefore
+// unexported). It is used as a building block for implementations of vectors of
+// a given metric type, like GaugeVec, CounterVec, SummaryVec, and HistogramVec.
+// It also handles label currying. It uses basicMetricVec internally.
+type metricVec struct {
+	*metricMap
 
-	newMetric   func(labelValues ...string) Metric
-	hashAdd     func(h uint64, s string) uint64 // replace hash function for testing collision handling
+	curry []curriedLabelValue
+
+	// hashAdd and hashAddByte can be replaced for testing collision handling.
+	hashAdd     func(h uint64, s string) uint64
 	hashAddByte func(h uint64, b byte) uint64
 }
 
-// newMetricVec returns an initialized MetricVec. The concrete value is
-// returned for embedding into another struct.
-func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec {
-	return &MetricVec{
-		children:    map[uint64][]metricWithLabelValues{},
-		desc:        desc,
-		newMetric:   newMetric,
+// newMetricVec returns an initialized metricVec.
+func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *metricVec {
+	return &metricVec{
+		metricMap: &metricMap{
+			metrics:   map[uint64][]metricWithLabelValues{},
+			desc:      desc,
+			newMetric: newMetric,
+		},
 		hashAdd:     hashAdd,
 		hashAddByte: hashAddByte,
 	}
 }
 
+// DeleteLabelValues removes the metric where the variable labels are the same
+// as those passed in as labels (same order as the VariableLabels in Desc). It
+// returns true if a metric was deleted.
+//
+// It is not an error if the number of label values is not the same as the
+// number of VariableLabels in Desc. However, such inconsistent label count can
+// never match an actual metric, so the method will always return false in that
+// case.
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider Delete(Labels) as an
+// alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the CounterVec example.
+func (m *metricVec) DeleteLabelValues(lvs ...string) bool {
+	h, err := m.hashLabelValues(lvs)
+	if err != nil {
+		return false
+	}
+
+	return m.metricMap.deleteByHashWithLabelValues(h, lvs, m.curry)
+}
+
+// Delete deletes the metric where the variable labels are the same as those
+// passed in as labels. It returns true if a metric was deleted.
+//
+// It is not an error if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc. However, such inconsistent Labels
+// can never match an actual metric, so the method will always return false in
+// that case.
+//
+// This method is used for the same purpose as DeleteLabelValues(...string). See
+// there for pros and cons of the two methods.
+func (m *metricVec) Delete(labels Labels) bool {
+	h, err := m.hashLabels(labels)
+	if err != nil {
+		return false
+	}
+
+	return m.metricMap.deleteByHashWithLabels(h, labels, m.curry)
+}
+
+func (m *metricVec) curryWith(labels Labels) (*metricVec, error) {
+	var (
+		newCurry []curriedLabelValue
+		oldCurry = m.curry
+		iCurry   int
+	)
+	for i, label := range m.desc.variableLabels {
+		val, ok := labels[label]
+		if iCurry < len(oldCurry) && oldCurry[iCurry].index == i {
+			if ok {
+				return nil, fmt.Errorf("label name %q is already curried", label)
+			}
+			newCurry = append(newCurry, oldCurry[iCurry])
+			iCurry++
+		} else {
+			if !ok {
+				continue // Label stays uncurried.
+			}
+			newCurry = append(newCurry, curriedLabelValue{i, val})
+		}
+	}
+	if l := len(oldCurry) + len(labels) - len(newCurry); l > 0 {
+		return nil, fmt.Errorf("%d unknown label(s) found during currying", l)
+	}
+
+	return &metricVec{
+		metricMap:   m.metricMap,
+		curry:       newCurry,
+		hashAdd:     m.hashAdd,
+		hashAddByte: m.hashAddByte,
+	}, nil
+}
+
+func (m *metricVec) getMetricWithLabelValues(lvs ...string) (Metric, error) {
+	h, err := m.hashLabelValues(lvs)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.metricMap.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil
+}
+
+func (m *metricVec) getMetricWith(labels Labels) (Metric, error) {
+	h, err := m.hashLabels(labels)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.metricMap.getOrCreateMetricWithLabels(h, labels, m.curry), nil
+}
+
+func (m *metricVec) hashLabelValues(vals []string) (uint64, error) {
+	if err := validateLabelValues(vals, len(m.desc.variableLabels)-len(m.curry)); err != nil {
+		return 0, err
+	}
+
+	var (
+		h             = hashNew()
+		curry         = m.curry
+		iVals, iCurry int
+	)
+	for i := 0; i < len(m.desc.variableLabels); i++ {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			h = m.hashAdd(h, curry[iCurry].value)
+			iCurry++
+		} else {
+			h = m.hashAdd(h, vals[iVals])
+			iVals++
+		}
+		h = m.hashAddByte(h, model.SeparatorByte)
+	}
+	return h, nil
+}
+
+func (m *metricVec) hashLabels(labels Labels) (uint64, error) {
+	if err := validateValuesInLabels(labels, len(m.desc.variableLabels)-len(m.curry)); err != nil {
+		return 0, err
+	}
+
+	var (
+		h      = hashNew()
+		curry  = m.curry
+		iCurry int
+	)
+	for i, label := range m.desc.variableLabels {
+		val, ok := labels[label]
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if ok {
+				return 0, fmt.Errorf("label name %q is already curried", label)
+			}
+			h = m.hashAdd(h, curry[iCurry].value)
+			iCurry++
+		} else {
+			if !ok {
+				return 0, fmt.Errorf("label name %q missing in label map", label)
+			}
+			h = m.hashAdd(h, val)
+		}
+		h = m.hashAddByte(h, model.SeparatorByte)
+	}
+	return h, nil
+}
+
 // metricWithLabelValues provides the metric and its label values for
 // disambiguation on hash collision.
 type metricWithLabelValues struct {
@@ -54,166 +201,72 @@ type metricWithLabelValues struct {
 	metric Metric
 }
 
-// Describe implements Collector. The length of the returned slice
-// is always one.
-func (m *MetricVec) Describe(ch chan<- *Desc) {
+// curriedLabelValue sets the curried value for a label at the given index.
+type curriedLabelValue struct {
+	index int
+	value string
+}
+
+// metricMap is a helper for metricVec and shared between differently curried
+// metricVecs.
+type metricMap struct {
+	mtx       sync.RWMutex // Protects metrics.
+	metrics   map[uint64][]metricWithLabelValues
+	desc      *Desc
+	newMetric func(labelValues ...string) Metric
+}
+
+// Describe implements Collector. It will send exactly one Desc to the provided
+// channel.
+func (m *metricMap) Describe(ch chan<- *Desc) {
 	ch <- m.desc
 }
 
 // Collect implements Collector.
-func (m *MetricVec) Collect(ch chan<- Metric) {
+func (m *metricMap) Collect(ch chan<- Metric) {
 	m.mtx.RLock()
 	defer m.mtx.RUnlock()
 
-	for _, metrics := range m.children {
+	for _, metrics := range m.metrics {
 		for _, metric := range metrics {
 			ch <- metric.metric
 		}
 	}
 }
 
-// GetMetricWithLabelValues returns the Metric for the given slice of label
-// values (same order as the VariableLabels in Desc). If that combination of
-// label values is accessed for the first time, a new Metric is created.
-//
-// It is possible to call this method without using the returned Metric to only
-// create the new Metric but leave it at its start value (e.g. a Summary or
-// Histogram without any observations). See also the SummaryVec example.
-//
-// Keeping the Metric for later use is possible (and should be considered if
-// performance is critical), but keep in mind that Reset, DeleteLabelValues and
-// Delete can be used to delete the Metric from the MetricVec. In that case, the
-// Metric will still exist, but it will not be exported anymore, even if a
-// Metric with the same label values is created later. See also the CounterVec
-// example.
-//
-// An error is returned if the number of label values is not the same as the
-// number of VariableLabels in Desc.
-//
-// Note that for more than one label value, this method is prone to mistakes
-// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
-// an alternative to avoid that type of mistake. For higher label numbers, the
-// latter has a much more readable (albeit more verbose) syntax, but it comes
-// with a performance overhead (for creating and processing the Labels map).
-// See also the GaugeVec example.
-func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
-	h, err := m.hashLabelValues(lvs)
-	if err != nil {
-		return nil, err
-	}
-
-	return m.getOrCreateMetricWithLabelValues(h, lvs), nil
-}
-
-// GetMetricWith returns the Metric for the given Labels map (the label names
-// must match those of the VariableLabels in Desc). If that label map is
-// accessed for the first time, a new Metric is created. Implications of
-// creating a Metric without using it and keeping the Metric for later use are
-// the same as for GetMetricWithLabelValues.
-//
-// An error is returned if the number and names of the Labels are inconsistent
-// with those of the VariableLabels in Desc.
-//
-// This method is used for the same purpose as
-// GetMetricWithLabelValues(...string). See there for pros and cons of the two
-// methods.
-func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) {
-	h, err := m.hashLabels(labels)
-	if err != nil {
-		return nil, err
-	}
-
-	return m.getOrCreateMetricWithLabels(h, labels), nil
-}
-
-// WithLabelValues works as GetMetricWithLabelValues, but panics if an error
-// occurs. The method allows neat syntax like:
-//     httpReqs.WithLabelValues("404", "POST").Inc()
-func (m *MetricVec) WithLabelValues(lvs ...string) Metric {
-	metric, err := m.GetMetricWithLabelValues(lvs...)
-	if err != nil {
-		panic(err)
-	}
-	return metric
-}
-
-// With works as GetMetricWith, but panics if an error occurs. The method allows
-// neat syntax like:
-//     httpReqs.With(Labels{"status":"404", "method":"POST"}).Inc()
-func (m *MetricVec) With(labels Labels) Metric {
-	metric, err := m.GetMetricWith(labels)
-	if err != nil {
-		panic(err)
-	}
-	return metric
-}
-
-// DeleteLabelValues removes the metric where the variable labels are the same
-// as those passed in as labels (same order as the VariableLabels in Desc). It
-// returns true if a metric was deleted.
-//
-// It is not an error if the number of label values is not the same as the
-// number of VariableLabels in Desc.  However, such inconsistent label count can
-// never match an actual Metric, so the method will always return false in that
-// case.
-//
-// Note that for more than one label value, this method is prone to mistakes
-// caused by an incorrect order of arguments. Consider Delete(Labels) as an
-// alternative to avoid that type of mistake. For higher label numbers, the
-// latter has a much more readable (albeit more verbose) syntax, but it comes
-// with a performance overhead (for creating and processing the Labels map).
-// See also the CounterVec example.
-func (m *MetricVec) DeleteLabelValues(lvs ...string) bool {
+// Reset deletes all metrics in this vector.
+func (m *metricMap) Reset() {
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
 
-	h, err := m.hashLabelValues(lvs)
-	if err != nil {
-		return false
+	for h := range m.metrics {
+		delete(m.metrics, h)
 	}
-	return m.deleteByHashWithLabelValues(h, lvs)
-}
-
-// Delete deletes the metric where the variable labels are the same as those
-// passed in as labels. It returns true if a metric was deleted.
-//
-// It is not an error if the number and names of the Labels are inconsistent
-// with those of the VariableLabels in the Desc of the MetricVec. However, such
-// inconsistent Labels can never match an actual Metric, so the method will
-// always return false in that case.
-//
-// This method is used for the same purpose as DeleteLabelValues(...string). See
-// there for pros and cons of the two methods.
-func (m *MetricVec) Delete(labels Labels) bool {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	h, err := m.hashLabels(labels)
-	if err != nil {
-		return false
-	}
-
-	return m.deleteByHashWithLabels(h, labels)
 }
 
 // deleteByHashWithLabelValues removes the metric from the hash bucket h. If
 // there are multiple matches in the bucket, use lvs to select a metric and
 // remove only that metric.
-func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
-	metrics, ok := m.children[h]
+func (m *metricMap) deleteByHashWithLabelValues(
+	h uint64, lvs []string, curry []curriedLabelValue,
+) bool {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	metrics, ok := m.metrics[h]
 	if !ok {
 		return false
 	}
 
-	i := m.findMetricWithLabelValues(metrics, lvs)
+	i := findMetricWithLabelValues(metrics, lvs, curry)
 	if i >= len(metrics) {
 		return false
 	}
 
 	if len(metrics) > 1 {
-		m.children[h] = append(metrics[:i], metrics[i+1:]...)
+		m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
 	} else {
-		delete(m.children, h)
+		delete(m.metrics, h)
 	}
 	return true
 }
@@ -221,69 +274,38 @@ func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
 // deleteByHashWithLabels removes the metric from the hash bucket h. If there
 // are multiple matches in the bucket, use lvs to select a metric and remove
 // only that metric.
-func (m *MetricVec) deleteByHashWithLabels(h uint64, labels Labels) bool {
-	metrics, ok := m.children[h]
+func (m *metricMap) deleteByHashWithLabels(
+	h uint64, labels Labels, curry []curriedLabelValue,
+) bool {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	metrics, ok := m.metrics[h]
 	if !ok {
 		return false
 	}
-	i := m.findMetricWithLabels(metrics, labels)
+	i := findMetricWithLabels(m.desc, metrics, labels, curry)
 	if i >= len(metrics) {
 		return false
 	}
 
 	if len(metrics) > 1 {
-		m.children[h] = append(metrics[:i], metrics[i+1:]...)
+		m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
 	} else {
-		delete(m.children, h)
+		delete(m.metrics, h)
 	}
 	return true
 }
 
-// Reset deletes all metrics in this vector.
-func (m *MetricVec) Reset() {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	for h := range m.children {
-		delete(m.children, h)
-	}
-}
-
-func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) {
-	if len(vals) != len(m.desc.variableLabels) {
-		return 0, errInconsistentCardinality
-	}
-	h := hashNew()
-	for _, val := range vals {
-		h = m.hashAdd(h, val)
-		h = m.hashAddByte(h, model.SeparatorByte)
-	}
-	return h, nil
-}
-
-func (m *MetricVec) hashLabels(labels Labels) (uint64, error) {
-	if len(labels) != len(m.desc.variableLabels) {
-		return 0, errInconsistentCardinality
-	}
-	h := hashNew()
-	for _, label := range m.desc.variableLabels {
-		val, ok := labels[label]
-		if !ok {
-			return 0, fmt.Errorf("label name %q missing in label map", label)
-		}
-		h = m.hashAdd(h, val)
-		h = m.hashAddByte(h, model.SeparatorByte)
-	}
-	return h, nil
-}
-
 // getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
 // or creates it and returns the new one.
 //
 // This function holds the mutex.
-func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) Metric {
+func (m *metricMap) getOrCreateMetricWithLabelValues(
+	hash uint64, lvs []string, curry []curriedLabelValue,
+) Metric {
 	m.mtx.RLock()
-	metric, ok := m.getMetricWithLabelValues(hash, lvs)
+	metric, ok := m.getMetricWithHashAndLabelValues(hash, lvs, curry)
 	m.mtx.RUnlock()
 	if ok {
 		return metric
@@ -291,13 +313,11 @@ func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string)
 
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
-	metric, ok = m.getMetricWithLabelValues(hash, lvs)
+	metric, ok = m.getMetricWithHashAndLabelValues(hash, lvs, curry)
 	if !ok {
-		// Copy to avoid allocation in case wo don't go down this code path.
-		copiedLVs := make([]string, len(lvs))
-		copy(copiedLVs, lvs)
-		metric = m.newMetric(copiedLVs...)
-		m.children[hash] = append(m.children[hash], metricWithLabelValues{values: copiedLVs, metric: metric})
+		inlinedLVs := inlineLabelValues(lvs, curry)
+		metric = m.newMetric(inlinedLVs...)
+		m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: inlinedLVs, metric: metric})
 	}
 	return metric
 }
@@ -306,9 +326,11 @@ func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string)
 // or creates it and returns the new one.
 //
 // This function holds the mutex.
-func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metric {
+func (m *metricMap) getOrCreateMetricWithLabels(
+	hash uint64, labels Labels, curry []curriedLabelValue,
+) Metric {
 	m.mtx.RLock()
-	metric, ok := m.getMetricWithLabels(hash, labels)
+	metric, ok := m.getMetricWithHashAndLabels(hash, labels, curry)
 	m.mtx.RUnlock()
 	if ok {
 		return metric
@@ -316,33 +338,37 @@ func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metr
 
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
-	metric, ok = m.getMetricWithLabels(hash, labels)
+	metric, ok = m.getMetricWithHashAndLabels(hash, labels, curry)
 	if !ok {
-		lvs := m.extractLabelValues(labels)
+		lvs := extractLabelValues(m.desc, labels, curry)
 		metric = m.newMetric(lvs...)
-		m.children[hash] = append(m.children[hash], metricWithLabelValues{values: lvs, metric: metric})
+		m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: lvs, metric: metric})
 	}
 	return metric
 }
 
-// getMetricWithLabelValues gets a metric while handling possible collisions in
-// the hash space. Must be called while holding read mutex.
-func (m *MetricVec) getMetricWithLabelValues(h uint64, lvs []string) (Metric, bool) {
-	metrics, ok := m.children[h]
+// getMetricWithHashAndLabelValues gets a metric while handling possible
+// collisions in the hash space. Must be called while holding the read mutex.
+func (m *metricMap) getMetricWithHashAndLabelValues(
+	h uint64, lvs []string, curry []curriedLabelValue,
+) (Metric, bool) {
+	metrics, ok := m.metrics[h]
 	if ok {
-		if i := m.findMetricWithLabelValues(metrics, lvs); i < len(metrics) {
+		if i := findMetricWithLabelValues(metrics, lvs, curry); i < len(metrics) {
 			return metrics[i].metric, true
 		}
 	}
 	return nil, false
 }
 
-// getMetricWithLabels gets a metric while handling possible collisions in
+// getMetricWithHashAndLabels gets a metric while handling possible collisions in
 // the hash space. Must be called while holding read mutex.
-func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool) {
-	metrics, ok := m.children[h]
+func (m *metricMap) getMetricWithHashAndLabels(
+	h uint64, labels Labels, curry []curriedLabelValue,
+) (Metric, bool) {
+	metrics, ok := m.metrics[h]
 	if ok {
-		if i := m.findMetricWithLabels(metrics, labels); i < len(metrics) {
+		if i := findMetricWithLabels(m.desc, metrics, labels, curry); i < len(metrics) {
 			return metrics[i].metric, true
 		}
 	}
@@ -351,9 +377,11 @@ func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool)
 
 // findMetricWithLabelValues returns the index of the matching metric or
 // len(metrics) if not found.
-func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, lvs []string) int {
+func findMetricWithLabelValues(
+	metrics []metricWithLabelValues, lvs []string, curry []curriedLabelValue,
+) int {
 	for i, metric := range metrics {
-		if m.matchLabelValues(metric.values, lvs) {
+		if matchLabelValues(metric.values, lvs, curry) {
 			return i
 		}
 	}
@@ -362,32 +390,51 @@ func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, l
 
 // findMetricWithLabels returns the index of the matching metric or len(metrics)
 // if not found.
-func (m *MetricVec) findMetricWithLabels(metrics []metricWithLabelValues, labels Labels) int {
+func findMetricWithLabels(
+	desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue,
+) int {
 	for i, metric := range metrics {
-		if m.matchLabels(metric.values, labels) {
+		if matchLabels(desc, metric.values, labels, curry) {
 			return i
 		}
 	}
 	return len(metrics)
 }
 
-func (m *MetricVec) matchLabelValues(values []string, lvs []string) bool {
-	if len(values) != len(lvs) {
+func matchLabelValues(values []string, lvs []string, curry []curriedLabelValue) bool {
+	if len(values) != len(lvs)+len(curry) {
 		return false
 	}
+	var iLVs, iCurry int
 	for i, v := range values {
-		if v != lvs[i] {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if v != curry[iCurry].value {
+				return false
+			}
+			iCurry++
+			continue
+		}
+		if v != lvs[iLVs] {
 			return false
 		}
+		iLVs++
 	}
 	return true
 }
 
-func (m *MetricVec) matchLabels(values []string, labels Labels) bool {
-	if len(labels) != len(values) {
+func matchLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool {
+	if len(values) != len(labels)+len(curry) {
 		return false
 	}
-	for i, k := range m.desc.variableLabels {
+	iCurry := 0
+	for i, k := range desc.variableLabels {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			if values[i] != curry[iCurry].value {
+				return false
+			}
+			iCurry++
+			continue
+		}
 		if values[i] != labels[k] {
 			return false
 		}
@@ -395,10 +442,31 @@ func (m *MetricVec) matchLabels(values []string, labels Labels) bool {
 	return true
 }
 
-func (m *MetricVec) extractLabelValues(labels Labels) []string {
-	labelValues := make([]string, len(labels))
-	for i, k := range m.desc.variableLabels {
+func extractLabelValues(desc *Desc, labels Labels, curry []curriedLabelValue) []string {
+	labelValues := make([]string, len(labels)+len(curry))
+	iCurry := 0
+	for i, k := range desc.variableLabels {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			labelValues[i] = curry[iCurry].value
+			iCurry++
+			continue
+		}
 		labelValues[i] = labels[k]
 	}
 	return labelValues
 }
+
+func inlineLabelValues(lvs []string, curry []curriedLabelValue) []string {
+	labelValues := make([]string, len(lvs)+len(curry))
+	var iCurry, iLVs int
+	for i := range labelValues {
+		if iCurry < len(curry) && curry[iCurry].index == i {
+			labelValues[i] = curry[iCurry].value
+			iCurry++
+			continue
+		}
+		labelValues[i] = lvs[iLVs]
+		iLVs++
+	}
+	return labelValues
+}

vendor/github.com/prometheus/client_golang/prometheus/wrap.go

@@ -0,0 +1,200 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// WrapRegistererWith returns a Registerer wrapping the provided
+// Registerer. Collectors registered with the returned Registerer will be
+// registered with the wrapped Registerer in a modified way. The modified
+// Collector adds the provided Labels to all Metrics it collects (as
+// ConstLabels). The Metrics collected by the unmodified Collector must not
+// duplicate any of those labels.
+//
+// WrapRegistererWith provides a way to add fixed labels to a subset of
+// Collectors. It should not be used to add fixed labels to all metrics exposed.
+//
+// Conflicts between Collectors registered through the original Registerer with
+// Collectors registered through the wrapping Registerer will still be
+// detected. Any AlreadyRegisteredError returned by the Register method of
+// either Registerer will contain the ExistingCollector in the form it was
+// provided to the respective registry.
+//
+// The Collector example demonstrates a use of WrapRegistererWith.
+func WrapRegistererWith(labels Labels, reg Registerer) Registerer {
+	return &wrappingRegisterer{
+		wrappedRegisterer: reg,
+		labels:            labels,
+	}
+}
+
+// WrapRegistererWithPrefix returns a Registerer wrapping the provided
+// Registerer. Collectors registered with the returned Registerer will be
+// registered with the wrapped Registerer in a modified way. The modified
+// Collector adds the provided prefix to the name of all Metrics it collects.
+//
+// WrapRegistererWithPrefix is useful to have one place to prefix all metrics of
+// a sub-system. To make this work, register metrics of the sub-system with the
+// wrapping Registerer returned by WrapRegistererWithPrefix. It is rarely useful
+// to use the same prefix for all metrics exposed. In particular, do not prefix
+// metric names that are standardized across applications, as that would break
+// horizontal monitoring, for example the metrics provided by the Go collector
+// (see NewGoCollector) and the process collector (see NewProcessCollector). (In
+// fact, those metrics are already prefixed with “go_” or “process_”,
+// respectively.)
+//
+// Conflicts between Collectors registered through the original Registerer with
+// Collectors registered through the wrapping Registerer will still be
+// detected. Any AlreadyRegisteredError returned by the Register method of
+// either Registerer will contain the ExistingCollector in the form it was
+// provided to the respective registry.
+func WrapRegistererWithPrefix(prefix string, reg Registerer) Registerer {
+	return &wrappingRegisterer{
+		wrappedRegisterer: reg,
+		prefix:            prefix,
+	}
+}
+
+type wrappingRegisterer struct {
+	wrappedRegisterer Registerer
+	prefix            string
+	labels            Labels
+}
+
+func (r *wrappingRegisterer) Register(c Collector) error {
+	return r.wrappedRegisterer.Register(&wrappingCollector{
+		wrappedCollector: c,
+		prefix:           r.prefix,
+		labels:           r.labels,
+	})
+}
+
+func (r *wrappingRegisterer) MustRegister(cs ...Collector) {
+	for _, c := range cs {
+		if err := r.Register(c); err != nil {
+			panic(err)
+		}
+	}
+}
+
+func (r *wrappingRegisterer) Unregister(c Collector) bool {
+	return r.wrappedRegisterer.Unregister(&wrappingCollector{
+		wrappedCollector: c,
+		prefix:           r.prefix,
+		labels:           r.labels,
+	})
+}
+
+type wrappingCollector struct {
+	wrappedCollector Collector
+	prefix           string
+	labels           Labels
+}
+
+func (c *wrappingCollector) Collect(ch chan<- Metric) {
+	wrappedCh := make(chan Metric)
+	go func() {
+		c.wrappedCollector.Collect(wrappedCh)
+		close(wrappedCh)
+	}()
+	for m := range wrappedCh {
+		ch <- &wrappingMetric{
+			wrappedMetric: m,
+			prefix:        c.prefix,
+			labels:        c.labels,
+		}
+	}
+}
+
+func (c *wrappingCollector) Describe(ch chan<- *Desc) {
+	wrappedCh := make(chan *Desc)
+	go func() {
+		c.wrappedCollector.Describe(wrappedCh)
+		close(wrappedCh)
+	}()
+	for desc := range wrappedCh {
+		ch <- wrapDesc(desc, c.prefix, c.labels)
+	}
+}
+
+func (c *wrappingCollector) unwrapRecursively() Collector {
+	switch wc := c.wrappedCollector.(type) {
+	case *wrappingCollector:
+		return wc.unwrapRecursively()
+	default:
+		return wc
+	}
+}
+
+type wrappingMetric struct {
+	wrappedMetric Metric
+	prefix        string
+	labels        Labels
+}
+
+func (m *wrappingMetric) Desc() *Desc {
+	return wrapDesc(m.wrappedMetric.Desc(), m.prefix, m.labels)
+}
+
+func (m *wrappingMetric) Write(out *dto.Metric) error {
+	if err := m.wrappedMetric.Write(out); err != nil {
+		return err
+	}
+	if len(m.labels) == 0 {
+		// No wrapping labels.
+		return nil
+	}
+	for ln, lv := range m.labels {
+		out.Label = append(out.Label, &dto.LabelPair{
+			Name:  proto.String(ln),
+			Value: proto.String(lv),
+		})
+	}
+	sort.Sort(labelPairSorter(out.Label))
+	return nil
+}
+
+func wrapDesc(desc *Desc, prefix string, labels Labels) *Desc {
+	constLabels := Labels{}
+	for _, lp := range desc.constLabelPairs {
+		constLabels[*lp.Name] = *lp.Value
+	}
+	for ln, lv := range labels {
+		if _, alreadyUsed := constLabels[ln]; alreadyUsed {
+			return &Desc{
+				fqName:          desc.fqName,
+				help:            desc.help,
+				variableLabels:  desc.variableLabels,
+				constLabelPairs: desc.constLabelPairs,
+				err:             fmt.Errorf("attempted wrapping with already existing label name %q", ln),
+			}
+		}
+		constLabels[ln] = lv
+	}
+	// NewDesc will do remaining validations.
+	newDesc := NewDesc(prefix+desc.fqName, desc.help, desc.variableLabels, constLabels)
+	// Propagate errors if there was any. This will override any errer
+	// created by NewDesc above, i.e. earlier errors get precedence.
+	if desc.err != nil {
+		newDesc.err = desc.err
+	}
+	return newDesc
+}

vendor/github.com/prometheus/common/expfmt/decode.go

@@ -164,9 +164,9 @@ func (sd *SampleDecoder) Decode(s *model.Vector) error {
 }
 
 // ExtractSamples builds a slice of samples from the provided metric
-// families. If an error occurs during sample extraction, it continues to
+// families. If an error occurrs during sample extraction, it continues to
 // extract from the remaining metric families. The returned error is the last
-// error that has occured.
+// error that has occurred.
 func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) (model.Vector, error) {
 	var (
 		all     model.Vector

vendor/github.com/prometheus/common/expfmt/expfmt.go

@@ -26,7 +26,7 @@ const (
 
 	// The Content-Type values for the different wire protocols.
 	FmtUnknown      Format = `<unknown>`
-	FmtText         Format = `text/plain; version=` + TextVersion
+	FmtText         Format = `text/plain; version=` + TextVersion + `; charset=utf-8`
 	FmtProtoDelim   Format = ProtoFmt + ` encoding=delimited`
 	FmtProtoText    Format = ProtoFmt + ` encoding=text`
 	FmtProtoCompact Format = ProtoFmt + ` encoding=compact-text`

vendor/github.com/prometheus/common/expfmt/text_create.go

@@ -14,13 +14,45 @@
 package expfmt
 
 import (
+	"bytes"
 	"fmt"
 	"io"
 	"math"
+	"strconv"
 	"strings"
+	"sync"
+
+	"github.com/prometheus/common/model"
 
 	dto "github.com/prometheus/client_model/go"
-	"github.com/prometheus/common/model"
+)
+
+// enhancedWriter has all the enhanced write functions needed here. bytes.Buffer
+// implements it.
+type enhancedWriter interface {
+	io.Writer
+	WriteRune(r rune) (n int, err error)
+	WriteString(s string) (n int, err error)
+	WriteByte(c byte) error
+}
+
+const (
+	initialBufSize    = 512
+	initialNumBufSize = 24
+)
+
+var (
+	bufPool = sync.Pool{
+		New: func() interface{} {
+			return bytes.NewBuffer(make([]byte, 0, initialBufSize))
+		},
+	}
+	numBufPool = sync.Pool{
+		New: func() interface{} {
+			b := make([]byte, 0, initialNumBufSize)
+			return &b
+		},
+	}
 )
 
 // MetricFamilyToText converts a MetricFamily proto message into text format and
@@ -32,37 +64,92 @@ import (
 // will result in invalid text format output.
 //
 // This method fulfills the type 'prometheus.encoder'.
-func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
-	var written int
-
+func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (written int, err error) {
 	// Fail-fast checks.
 	if len(in.Metric) == 0 {
-		return written, fmt.Errorf("MetricFamily has no metrics: %s", in)
+		return 0, fmt.Errorf("MetricFamily has no metrics: %s", in)
 	}
 	name := in.GetName()
 	if name == "" {
-		return written, fmt.Errorf("MetricFamily has no name: %s", in)
+		return 0, fmt.Errorf("MetricFamily has no name: %s", in)
 	}
 
+	// Try the interface upgrade. If it doesn't work, we'll use a
+	// bytes.Buffer from the sync.Pool and write out its content to out in a
+	// single go in the end.
+	w, ok := out.(enhancedWriter)
+	if !ok {
+		b := bufPool.Get().(*bytes.Buffer)
+		b.Reset()
+		w = b
+		defer func() {
+			bWritten, bErr := out.Write(b.Bytes())
+			written = bWritten
+			if err == nil {
+				err = bErr
+			}
+			bufPool.Put(b)
+		}()
+	}
+
+	var n int
+
 	// Comments, first HELP, then TYPE.
 	if in.Help != nil {
-		n, err := fmt.Fprintf(
-			out, "# HELP %s %s\n",
-			name, escapeString(*in.Help, false),
-		)
+		n, err = w.WriteString("# HELP ")
 		written += n
 		if err != nil {
-			return written, err
+			return
+		}
+		n, err = w.WriteString(name)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return
+		}
+		n, err = writeEscapedString(w, *in.Help, false)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte('\n')
+		written++
+		if err != nil {
+			return
 		}
 	}
-	metricType := in.GetType()
-	n, err := fmt.Fprintf(
-		out, "# TYPE %s %s\n",
-		name, strings.ToLower(metricType.String()),
-	)
+	n, err = w.WriteString("# TYPE ")
 	written += n
 	if err != nil {
-		return written, err
+		return
+	}
+	n, err = w.WriteString(name)
+	written += n
+	if err != nil {
+		return
+	}
+	metricType := in.GetType()
+	switch metricType {
+	case dto.MetricType_COUNTER:
+		n, err = w.WriteString(" counter\n")
+	case dto.MetricType_GAUGE:
+		n, err = w.WriteString(" gauge\n")
+	case dto.MetricType_SUMMARY:
+		n, err = w.WriteString(" summary\n")
+	case dto.MetricType_UNTYPED:
+		n, err = w.WriteString(" untyped\n")
+	case dto.MetricType_HISTOGRAM:
+		n, err = w.WriteString(" histogram\n")
+	default:
+		return written, fmt.Errorf("unknown metric type %s", metricType.String())
+	}
+	written += n
+	if err != nil {
+		return
 	}
 
 	// Finally the samples, one line for each.
@@ -75,9 +162,8 @@ func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
 				)
 			}
 			n, err = writeSample(
-				name, metric, "", "",
+				w, name, "", metric, "", 0,
 				metric.Counter.GetValue(),
-				out,
 			)
 		case dto.MetricType_GAUGE:
 			if metric.Gauge == nil {
@@ -86,9 +172,8 @@ func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
 				)
 			}
 			n, err = writeSample(
-				name, metric, "", "",
+				w, name, "", metric, "", 0,
 				metric.Gauge.GetValue(),
-				out,
 			)
 		case dto.MetricType_UNTYPED:
 			if metric.Untyped == nil {
@@ -97,9 +182,8 @@ func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
 				)
 			}
 			n, err = writeSample(
-				name, metric, "", "",
+				w, name, "", metric, "", 0,
 				metric.Untyped.GetValue(),
-				out,
 			)
 		case dto.MetricType_SUMMARY:
 			if metric.Summary == nil {
@@ -109,29 +193,26 @@ func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
 			}
 			for _, q := range metric.Summary.Quantile {
 				n, err = writeSample(
-					name, metric,
-					model.QuantileLabel, fmt.Sprint(q.GetQuantile()),
+					w, name, "", metric,
+					model.QuantileLabel, q.GetQuantile(),
 					q.GetValue(),
-					out,
 				)
 				written += n
 				if err != nil {
-					return written, err
+					return
 				}
 			}
 			n, err = writeSample(
-				name+"_sum", metric, "", "",
+				w, name, "_sum", metric, "", 0,
 				metric.Summary.GetSampleSum(),
-				out,
 			)
-			if err != nil {
-				return written, err
-			}
 			written += n
+			if err != nil {
+				return
+			}
 			n, err = writeSample(
-				name+"_count", metric, "", "",
+				w, name, "_count", metric, "", 0,
 				float64(metric.Summary.GetSampleCount()),
-				out,
 			)
 		case dto.MetricType_HISTOGRAM:
 			if metric.Histogram == nil {
@@ -140,46 +221,42 @@ func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
 				)
 			}
 			infSeen := false
-			for _, q := range metric.Histogram.Bucket {
+			for _, b := range metric.Histogram.Bucket {
 				n, err = writeSample(
-					name+"_bucket", metric,
-					model.BucketLabel, fmt.Sprint(q.GetUpperBound()),
-					float64(q.GetCumulativeCount()),
-					out,
+					w, name, "_bucket", metric,
+					model.BucketLabel, b.GetUpperBound(),
+					float64(b.GetCumulativeCount()),
 				)
 				written += n
 				if err != nil {
-					return written, err
+					return
 				}
-				if math.IsInf(q.GetUpperBound(), +1) {
+				if math.IsInf(b.GetUpperBound(), +1) {
 					infSeen = true
 				}
 			}
 			if !infSeen {
 				n, err = writeSample(
-					name+"_bucket", metric,
-					model.BucketLabel, "+Inf",
+					w, name, "_bucket", metric,
+					model.BucketLabel, math.Inf(+1),
 					float64(metric.Histogram.GetSampleCount()),
-					out,
 				)
-				if err != nil {
-					return written, err
-				}
 				written += n
+				if err != nil {
+					return
+				}
 			}
 			n, err = writeSample(
-				name+"_sum", metric, "", "",
+				w, name, "_sum", metric, "", 0,
 				metric.Histogram.GetSampleSum(),
-				out,
 			)
-			if err != nil {
-				return written, err
-			}
 			written += n
+			if err != nil {
+				return
+			}
 			n, err = writeSample(
-				name+"_count", metric, "", "",
+				w, name, "_count", metric, "", 0,
 				float64(metric.Histogram.GetSampleCount()),
-				out,
 			)
 		default:
 			return written, fmt.Errorf(
@@ -188,116 +265,204 @@ func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
 		}
 		written += n
 		if err != nil {
-			return written, err
+			return
 		}
 	}
-	return written, nil
+	return
 }
 
-// writeSample writes a single sample in text format to out, given the metric
+// writeSample writes a single sample in text format to w, given the metric
 // name, the metric proto message itself, optionally an additional label name
-// and value (use empty strings if not required), and the value. The function
-// returns the number of bytes written and any error encountered.
+// with a float64 value (use empty string as label name if not required), and
+// the value. The function returns the number of bytes written and any error
+// encountered.
 func writeSample(
-	name string,
+	w enhancedWriter,
+	name, suffix string,
 	metric *dto.Metric,
-	additionalLabelName, additionalLabelValue string,
+	additionalLabelName string, additionalLabelValue float64,
 	value float64,
-	out io.Writer,
 ) (int, error) {
 	var written int
-	n, err := fmt.Fprint(out, name)
+	n, err := w.WriteString(name)
 	written += n
 	if err != nil {
 		return written, err
 	}
-	n, err = labelPairsToText(
-		metric.Label,
-		additionalLabelName, additionalLabelValue,
-		out,
-	)
-	written += n
-	if err != nil {
-		return written, err
-	}
-	n, err = fmt.Fprintf(out, " %v", value)
-	written += n
-	if err != nil {
-		return written, err
-	}
-	if metric.TimestampMs != nil {
-		n, err = fmt.Fprintf(out, " %v", *metric.TimestampMs)
+	if suffix != "" {
+		n, err = w.WriteString(suffix)
 		written += n
 		if err != nil {
 			return written, err
 		}
 	}
-	n, err = out.Write([]byte{'\n'})
+	n, err = writeLabelPairs(
+		w, metric.Label, additionalLabelName, additionalLabelValue,
+	)
 	written += n
 	if err != nil {
 		return written, err
 	}
+	err = w.WriteByte(' ')
+	written++
+	if err != nil {
+		return written, err
+	}
+	n, err = writeFloat(w, value)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if metric.TimestampMs != nil {
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err = writeInt(w, *metric.TimestampMs)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	err = w.WriteByte('\n')
+	written++
+	if err != nil {
+		return written, err
+	}
 	return written, nil
 }
 
-// labelPairsToText converts a slice of LabelPair proto messages plus the
+// writeLabelPairs converts a slice of LabelPair proto messages plus the
 // explicitly given additional label pair into text formatted as required by the
-// text format and writes it to 'out'. An empty slice in combination with an
-// empty string 'additionalLabelName' results in nothing being
-// written. Otherwise, the label pairs are written, escaped as required by the
-// text format, and enclosed in '{...}'. The function returns the number of
-// bytes written and any error encountered.
-func labelPairsToText(
+// text format and writes it to 'w'. An empty slice in combination with an empty
+// string 'additionalLabelName' results in nothing being written. Otherwise, the
+// label pairs are written, escaped as required by the text format, and enclosed
+// in '{...}'. The function returns the number of bytes written and any error
+// encountered.
+func writeLabelPairs(
+	w enhancedWriter,
 	in []*dto.LabelPair,
-	additionalLabelName, additionalLabelValue string,
-	out io.Writer,
+	additionalLabelName string, additionalLabelValue float64,
 ) (int, error) {
 	if len(in) == 0 && additionalLabelName == "" {
 		return 0, nil
 	}
-	var written int
-	separator := '{'
+	var (
+		written   int
+		separator byte = '{'
+	)
 	for _, lp := range in {
-		n, err := fmt.Fprintf(
-			out, `%c%s="%s"`,
-			separator, lp.GetName(), escapeString(lp.GetValue(), true),
-		)
+		err := w.WriteByte(separator)
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err := w.WriteString(lp.GetName())
 		written += n
 		if err != nil {
 			return written, err
 		}
+		n, err = w.WriteString(`="`)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = writeEscapedString(w, lp.GetValue(), true)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		err = w.WriteByte('"')
+		written++
+		if err != nil {
+			return written, err
+		}
 		separator = ','
 	}
 	if additionalLabelName != "" {
-		n, err := fmt.Fprintf(
-			out, `%c%s="%s"`,
-			separator, additionalLabelName,
-			escapeString(additionalLabelValue, true),
-		)
+		err := w.WriteByte(separator)
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err := w.WriteString(additionalLabelName)
 		written += n
 		if err != nil {
 			return written, err
 		}
+		n, err = w.WriteString(`="`)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = writeFloat(w, additionalLabelValue)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		err = w.WriteByte('"')
+		written++
+		if err != nil {
+			return written, err
+		}
 	}
-	n, err := out.Write([]byte{'}'})
-	written += n
+	err := w.WriteByte('}')
+	written++
 	if err != nil {
 		return written, err
 	}
 	return written, nil
 }
 
+// writeEscapedString replaces '\' by '\\', new line character by '\n', and - if
+// includeDoubleQuote is true - '"' by '\"'.
 var (
-	escape                = strings.NewReplacer("\\", `\\`, "\n", `\n`)
-	escapeWithDoubleQuote = strings.NewReplacer("\\", `\\`, "\n", `\n`, "\"", `\"`)
+	escaper       = strings.NewReplacer("\\", `\\`, "\n", `\n`)
+	quotedEscaper = strings.NewReplacer("\\", `\\`, "\n", `\n`, "\"", `\"`)
 )
 
-// escapeString replaces '\' by '\\', new line character by '\n', and - if
-// includeDoubleQuote is true - '"' by '\"'.
-func escapeString(v string, includeDoubleQuote bool) string {
+func writeEscapedString(w enhancedWriter, v string, includeDoubleQuote bool) (int, error) {
 	if includeDoubleQuote {
-		return escapeWithDoubleQuote.Replace(v)
+		return quotedEscaper.WriteString(w, v)
+	} else {
+		return escaper.WriteString(w, v)
 	}
-
-	return escape.Replace(v)
+}
+
+// writeFloat is equivalent to fmt.Fprint with a float64 argument but hardcodes
+// a few common cases for increased efficiency. For non-hardcoded cases, it uses
+// strconv.AppendFloat to avoid allocations, similar to writeInt.
+func writeFloat(w enhancedWriter, f float64) (int, error) {
+	switch {
+	case f == 1:
+		return 1, w.WriteByte('1')
+	case f == 0:
+		return 1, w.WriteByte('0')
+	case f == -1:
+		return w.WriteString("-1")
+	case math.IsNaN(f):
+		return w.WriteString("NaN")
+	case math.IsInf(f, +1):
+		return w.WriteString("+Inf")
+	case math.IsInf(f, -1):
+		return w.WriteString("-Inf")
+	default:
+		bp := numBufPool.Get().(*[]byte)
+		*bp = strconv.AppendFloat((*bp)[:0], f, 'g', -1, 64)
+		written, err := w.Write(*bp)
+		numBufPool.Put(bp)
+		return written, err
+	}
+}
+
+// writeInt is equivalent to fmt.Fprint with an int64 argument but uses
+// strconv.AppendInt with a byte slice taken from a sync.Pool to avoid
+// allocations.
+func writeInt(w enhancedWriter, i int64) (int, error) {
+	bp := numBufPool.Get().(*[]byte)
+	*bp = strconv.AppendInt((*bp)[:0], i, 10)
+	written, err := w.Write(*bp)
+	numBufPool.Put(bp)
+	return written, err
 }

vendor/github.com/prometheus/common/expfmt/text_parse.go

@@ -315,6 +315,10 @@ func (p *TextParser) startLabelValue() stateFn {
 	if p.readTokenAsLabelValue(); p.err != nil {
 		return nil
 	}
+	if !model.LabelValue(p.currentToken.String()).IsValid() {
+		p.parseError(fmt.Sprintf("invalid label value %q", p.currentToken.String()))
+		return nil
+	}
 	p.currentLabelPair.Value = proto.String(p.currentToken.String())
 	// Special treatment of summaries:
 	// - Quantile labels are special, will result in dto.Quantile later.
@@ -355,7 +359,7 @@ func (p *TextParser) startLabelValue() stateFn {
 		}
 		return p.readingValue
 	default:
-		p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.Value))
+		p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.GetValue()))
 		return nil
 	}
 }
@@ -552,8 +556,8 @@ func (p *TextParser) readTokenUntilWhitespace() {
 // byte considered is the byte already read (now in p.currentByte).  The first
 // newline byte encountered is still copied into p.currentByte, but not into
 // p.currentToken. If recognizeEscapeSequence is true, two escape sequences are
-// recognized: '\\' tranlates into '\', and '\n' into a line-feed character. All
-// other escape sequences are invalid and cause an error.
+// recognized: '\\' translates into '\', and '\n' into a line-feed character.
+// All other escape sequences are invalid and cause an error.
 func (p *TextParser) readTokenUntilNewline(recognizeEscapeSequence bool) {
 	p.currentToken.Reset()
 	escaped := false

vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/autoneg.go

@@ -1,12 +1,12 @@
 /*
+Copyright (c) 2011, Open Knowledge Foundation Ltd.
+All rights reserved.
+
 HTTP Content-Type Autonegotiation.
 
 The functions in this package implement the behaviour specified in
 http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
 
-Copyright (c) 2011, Open Knowledge Foundation Ltd.
-All rights reserved.
-
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are
 met:

vendor/github.com/prometheus/common/model/metric.go

@@ -21,7 +21,6 @@ import (
 )
 
 var (
-	separator = []byte{0}
 	// MetricNameRE is a regular expression matching valid metric
 	// names. Note that the IsValidMetricName function performs the same
 	// check but faster than a match with this regular expression.

vendor/github.com/prometheus/common/model/silence.go

@@ -59,8 +59,8 @@ func (m *Matcher) Validate() error {
 	return nil
 }
 
-// Silence defines the representation of a silence definiton
-// in the Prometheus eco-system.
+// Silence defines the representation of a silence definition in the Prometheus
+// eco-system.
 type Silence struct {
 	ID uint64 `json:"id,omitempty"`
 

vendor/github.com/prometheus/common/model/time.go

@@ -43,7 +43,7 @@ const (
 // (1970-01-01 00:00 UTC) excluding leap seconds.
 type Time int64
 
-// Interval describes and interval between two timestamps.
+// Interval describes an interval between two timestamps.
 type Interval struct {
 	Start, End Time
 }
@@ -150,7 +150,13 @@ func (t *Time) UnmarshalJSON(b []byte) error {
 			return err
 		}
 
-		*t = Time(v + va)
+		// If the value was something like -0.1 the negative is lost in the
+		// parsing because of the leading zero, this ensures that we capture it.
+		if len(p[0]) > 0 && p[0][0] == '-' && v+va > 0 {
+			*t = Time(v+va) * -1
+		} else {
+			*t = Time(v + va)
+		}
 
 	default:
 		return fmt.Errorf("invalid time %q", string(b))
@@ -163,9 +169,21 @@ func (t *Time) UnmarshalJSON(b []byte) error {
 // This type should not propagate beyond the scope of input/output processing.
 type Duration time.Duration
 
+// Set implements pflag/flag.Value
+func (d *Duration) Set(s string) error {
+	var err error
+	*d, err = ParseDuration(s)
+	return err
+}
+
+// Type implements pflag.Value
+func (d *Duration) Type() string {
+	return "duration"
+}
+
 var durationRE = regexp.MustCompile("^([0-9]+)(y|w|d|h|m|s|ms)$")
 
-// StringToDuration parses a string into a time.Duration, assuming that a year
+// ParseDuration parses a string into a time.Duration, assuming that a year
 // always has 365d, a week always has 7d, and a day always has 24h.
 func ParseDuration(durationStr string) (Duration, error) {
 	matches := durationRE.FindStringSubmatch(durationStr)
@@ -202,6 +220,9 @@ func (d Duration) String() string {
 		ms   = int64(time.Duration(d) / time.Millisecond)
 		unit = "ms"
 	)
+	if ms == 0 {
+		return "0s"
+	}
 	factors := map[string]int64{
 		"y":  1000 * 60 * 60 * 24 * 365,
 		"w":  1000 * 60 * 60 * 24 * 7,

vendor/github.com/prometheus/common/model/value.go

@@ -100,7 +100,7 @@ func (s *SamplePair) UnmarshalJSON(b []byte) error {
 }
 
 // Equal returns true if this SamplePair and o have equal Values and equal
-// Timestamps. The sematics of Value equality is defined by SampleValue.Equal.
+// Timestamps. The semantics of Value equality is defined by SampleValue.Equal.
 func (s *SamplePair) Equal(o *SamplePair) bool {
 	return s == o || (s.Value.Equal(o.Value) && s.Timestamp.Equal(o.Timestamp))
 }
@@ -117,7 +117,7 @@ type Sample struct {
 }
 
 // Equal compares first the metrics, then the timestamp, then the value. The
-// sematics of value equality is defined by SampleValue.Equal.
+// semantics of value equality is defined by SampleValue.Equal.
 func (s *Sample) Equal(o *Sample) bool {
 	if s == o {
 		return true

vendor/github.com/prometheus/procfs/buddyinfo.go

@@ -31,19 +31,9 @@ type BuddyInfo struct {
 	Sizes []float64
 }
 
-// NewBuddyInfo reads the buddyinfo statistics.
-func NewBuddyInfo() ([]BuddyInfo, error) {
-	fs, err := NewFS(DefaultMountPoint)
-	if err != nil {
-		return nil, err
-	}
-
-	return fs.NewBuddyInfo()
-}
-
 // NewBuddyInfo reads the buddyinfo statistics from the specified `proc` filesystem.
-func (fs FS) NewBuddyInfo() ([]BuddyInfo, error) {
-	file, err := os.Open(fs.Path("buddyinfo"))
+func (fs FS) BuddyInfo() ([]BuddyInfo, error) {
+	file, err := os.Open(fs.proc.Path("buddyinfo"))
 	if err != nil {
 		return nil, err
 	}
@@ -62,7 +52,7 @@ func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
 	for scanner.Scan() {
 		var err error
 		line := scanner.Text()
-		parts := strings.Fields(string(line))
+		parts := strings.Fields(line)
 
 		if len(parts) < 4 {
 			return nil, fmt.Errorf("invalid number of fields when parsing buddyinfo")

vendor/github.com/prometheus/procfs/fs.go

@@ -1,46 +1,43 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package procfs
 
 import (
-	"fmt"
-	"os"
-	"path"
-
-	"github.com/prometheus/procfs/xfs"
+	"github.com/prometheus/procfs/internal/fs"
 )
 
-// FS represents the pseudo-filesystem proc, which provides an interface to
+// FS represents the pseudo-filesystem sys, which provides an interface to
 // kernel data structures.
-type FS string
+type FS struct {
+	proc fs.FS
+}
 
 // DefaultMountPoint is the common mount point of the proc filesystem.
-const DefaultMountPoint = "/proc"
+const DefaultMountPoint = fs.DefaultProcMountPoint
 
-// NewFS returns a new FS mounted under the given mountPoint. It will error
-// if the mount point can't be read.
+// NewDefaultFS returns a new proc FS mounted under the default proc mountPoint.
+// It will error if the mount point directory can't be read or is a file.
+func NewDefaultFS() (FS, error) {
+	return NewFS(DefaultMountPoint)
+}
+
+// NewFS returns a new proc FS mounted under the given proc mountPoint. It will error
+// if the mount point directory can't be read or is a file.
 func NewFS(mountPoint string) (FS, error) {
-	info, err := os.Stat(mountPoint)
+	fs, err := fs.NewFS(mountPoint)
 	if err != nil {
-		return "", fmt.Errorf("could not read %s: %s", mountPoint, err)
+		return FS{}, err
 	}
-	if !info.IsDir() {
-		return "", fmt.Errorf("mount point %s is not a directory", mountPoint)
-	}
-
-	return FS(mountPoint), nil
-}
-
-// Path returns the path of the given subsystem relative to the procfs root.
-func (fs FS) Path(p ...string) string {
-	return path.Join(append([]string{string(fs)}, p...)...)
-}
-
-// XFSStats retrieves XFS filesystem runtime statistics.
-func (fs FS) XFSStats() (*xfs.Stats, error) {
-	f, err := os.Open(fs.Path("fs/xfs/stat"))
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	return xfs.ParseStats(f)
+	return FS{fs}, nil
 }

vendor/github.com/prometheus/procfs/internal/fs/fs.go

@@ -0,0 +1,55 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fs
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+const (
+	// DefaultProcMountPoint is the common mount point of the proc filesystem.
+	DefaultProcMountPoint = "/proc"
+
+	// DefaultSysMountPoint is the common mount point of the sys filesystem.
+	DefaultSysMountPoint = "/sys"
+
+	// DefaultConfigfsMountPoint is the commont mount point of the configfs
+	DefaultConfigfsMountPoint = "/sys/kernel/config"
+)
+
+// FS represents a pseudo-filesystem, normally /proc or /sys, which provides an
+// interface to kernel data structures.
+type FS string
+
+// NewFS returns a new FS mounted under the given mountPoint. It will error
+// if the mount point can't be read.
+func NewFS(mountPoint string) (FS, error) {
+	info, err := os.Stat(mountPoint)
+	if err != nil {
+		return "", fmt.Errorf("could not read %s: %s", mountPoint, err)
+	}
+	if !info.IsDir() {
+		return "", fmt.Errorf("mount point %s is not a directory", mountPoint)
+	}
+
+	return FS(mountPoint), nil
+}
+
+// Path appends the given path elements to the filesystem path, adding separators
+// as necessary.
+func (fs FS) Path(p ...string) string {
+	return filepath.Join(append([]string{string(fs)}, p...)...)
+}

vendor/github.com/prometheus/procfs/ipvs.go

@@ -1,3 +1,16 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package procfs
 
 import (
@@ -31,14 +44,16 @@ type IPVSStats struct {
 type IPVSBackendStatus struct {
 	// The local (virtual) IP address.
 	LocalAddress net.IP
-	// The local (virtual) port.
-	LocalPort uint16
-	// The transport protocol (TCP, UDP).
-	Proto string
 	// The remote (real) IP address.
 	RemoteAddress net.IP
+	// The local (virtual) port.
+	LocalPort uint16
 	// The remote (real) port.
 	RemotePort uint16
+	// The local firewall mark
+	LocalMark string
+	// The transport protocol (TCP, UDP).
+	Proto string
 	// The current number of active connections for this virtual/real address pair.
 	ActiveConn uint64
 	// The current number of inactive connections for this virtual/real address pair.
@@ -47,19 +62,9 @@ type IPVSBackendStatus struct {
 	Weight uint64
 }
 
-// NewIPVSStats reads the IPVS statistics.
-func NewIPVSStats() (IPVSStats, error) {
-	fs, err := NewFS(DefaultMountPoint)
-	if err != nil {
-		return IPVSStats{}, err
-	}
-
-	return fs.NewIPVSStats()
-}
-
-// NewIPVSStats reads the IPVS statistics from the specified `proc` filesystem.
-func (fs FS) NewIPVSStats() (IPVSStats, error) {
-	file, err := os.Open(fs.Path("net/ip_vs_stats"))
+// IPVSStats reads the IPVS statistics from the specified `proc` filesystem.
+func (fs FS) IPVSStats() (IPVSStats, error) {
+	file, err := os.Open(fs.proc.Path("net/ip_vs_stats"))
 	if err != nil {
 		return IPVSStats{}, err
 	}
@@ -116,19 +121,9 @@ func parseIPVSStats(file io.Reader) (IPVSStats, error) {
 	return stats, nil
 }
 
-// NewIPVSBackendStatus reads and returns the status of all (virtual,real) server pairs.
-func NewIPVSBackendStatus() ([]IPVSBackendStatus, error) {
-	fs, err := NewFS(DefaultMountPoint)
-	if err != nil {
-		return []IPVSBackendStatus{}, err
-	}
-
-	return fs.NewIPVSBackendStatus()
-}
-
-// NewIPVSBackendStatus reads and returns the status of all (virtual,real) server pairs from the specified `proc` filesystem.
-func (fs FS) NewIPVSBackendStatus() ([]IPVSBackendStatus, error) {
-	file, err := os.Open(fs.Path("net/ip_vs"))
+// IPVSBackendStatus reads and returns the status of all (virtual,real) server pairs from the specified `proc` filesystem.
+func (fs FS) IPVSBackendStatus() ([]IPVSBackendStatus, error) {
+	file, err := os.Open(fs.proc.Path("net/ip_vs"))
 	if err != nil {
 		return nil, err
 	}
@@ -142,13 +137,14 @@ func parseIPVSBackendStatus(file io.Reader) ([]IPVSBackendStatus, error) {
 		status       []IPVSBackendStatus
 		scanner      = bufio.NewScanner(file)
 		proto        string
+		localMark    string
 		localAddress net.IP
 		localPort    uint16
 		err          error
 	)
 
 	for scanner.Scan() {
-		fields := strings.Fields(string(scanner.Text()))
+		fields := strings.Fields(scanner.Text())
 		if len(fields) == 0 {
 			continue
 		}
@@ -160,10 +156,19 @@ func parseIPVSBackendStatus(file io.Reader) ([]IPVSBackendStatus, error) {
 				continue
 			}
 			proto = fields[0]
+			localMark = ""
 			localAddress, localPort, err = parseIPPort(fields[1])
 			if err != nil {
 				return nil, err
 			}
+		case fields[0] == "FWM":
+			if len(fields) < 2 {
+				continue
+			}
+			proto = fields[0]
+			localMark = fields[1]
+			localAddress = nil
+			localPort = 0
 		case fields[0] == "->":
 			if len(fields) < 6 {
 				continue
@@ -187,6 +192,7 @@ func parseIPVSBackendStatus(file io.Reader) ([]IPVSBackendStatus, error) {
 			status = append(status, IPVSBackendStatus{
 				LocalAddress:  localAddress,
 				LocalPort:     localPort,
+				LocalMark:     localMark,
 				RemoteAddress: remoteAddress,
 				RemotePort:    remotePort,
 				Proto:         proto,
@@ -200,22 +206,31 @@ func parseIPVSBackendStatus(file io.Reader) ([]IPVSBackendStatus, error) {
 }
 
 func parseIPPort(s string) (net.IP, uint16, error) {
-	tmp := strings.SplitN(s, ":", 2)
+	var (
+		ip  net.IP
+		err error
+	)
 
-	if len(tmp) != 2 {
-		return nil, 0, fmt.Errorf("invalid IP:Port: %s", s)
+	switch len(s) {
+	case 13:
+		ip, err = hex.DecodeString(s[0:8])
+		if err != nil {
+			return nil, 0, err
+		}
+	case 46:
+		ip = net.ParseIP(s[1:40])
+		if ip == nil {
+			return nil, 0, fmt.Errorf("invalid IPv6 address: %s", s[1:40])
+		}
+	default:
+		return nil, 0, fmt.Errorf("unexpected IP:Port: %s", s)
 	}
 
-	if len(tmp[0]) != 8 && len(tmp[0]) != 32 {
-		return nil, 0, fmt.Errorf("invalid IP: %s", tmp[0])
+	portString := s[len(s)-4:]
+	if len(portString) != 4 {
+		return nil, 0, fmt.Errorf("unexpected port string format: %s", portString)
 	}
-
-	ip, err := hex.DecodeString(tmp[0])
-	if err != nil {
-		return nil, 0, err
-	}
-
-	port, err := strconv.ParseUint(tmp[1], 16, 16)
+	port, err := strconv.ParseUint(portString, 16, 16)
 	if err != nil {
 		return nil, 0, err
 	}

vendor/github.com/prometheus/procfs/mdstat.go

@@ -1,3 +1,16 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package procfs
 
 import (
@@ -9,8 +22,8 @@ import (
 )
 
 var (
-	statuslineRE = regexp.MustCompile(`(\d+) blocks .*\[(\d+)/(\d+)\] \[[U_]+\]`)
-	buildlineRE  = regexp.MustCompile(`\((\d+)/\d+\)`)
+	statusLineRE   = regexp.MustCompile(`(\d+) blocks .*\[(\d+)/(\d+)\] \[[U_]+\]`)
+	recoveryLineRE = regexp.MustCompile(`\((\d+)/\d+\)`)
 )
 
 // MDStat holds info parsed from /proc/mdstat.
@@ -21,117 +34,160 @@ type MDStat struct {
 	ActivityState string
 	// Number of active disks.
 	DisksActive int64
-	// Total number of disks the device consists of.
+	// Total number of disks the device requires.
 	DisksTotal int64
+	// Number of failed disks.
+	DisksFailed int64
+	// Spare disks in the device.
+	DisksSpare int64
 	// Number of blocks the device holds.
 	BlocksTotal int64
 	// Number of blocks on the device that are in sync.
 	BlocksSynced int64
 }
 
-// ParseMDStat parses an mdstat-file and returns a struct with the relevant infos.
-func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
-	mdStatusFilePath := fs.Path("mdstat")
-	content, err := ioutil.ReadFile(mdStatusFilePath)
+// MDStat parses an mdstat-file (/proc/mdstat) and returns a slice of
+// structs containing the relevant info.  More information available here:
+// https://raid.wiki.kernel.org/index.php/Mdstat
+func (fs FS) MDStat() ([]MDStat, error) {
+	data, err := ioutil.ReadFile(fs.proc.Path("mdstat"))
 	if err != nil {
-		return []MDStat{}, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+		return nil, fmt.Errorf("error parsing mdstat %s: %s", fs.proc.Path("mdstat"), err)
 	}
+	mdstat, err := parseMDStat(data)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing mdstat %s: %s", fs.proc.Path("mdstat"), err)
+	}
+	return mdstat, nil
+}
 
-	mdStates := []MDStat{}
-	lines := strings.Split(string(content), "\n")
-	for i, l := range lines {
-		if l == "" {
-			continue
-		}
-		if l[0] == ' ' {
-			continue
-		}
-		if strings.HasPrefix(l, "Personalities") || strings.HasPrefix(l, "unused") {
+// parseMDStat parses data from mdstat file (/proc/mdstat) and returns a slice of
+// structs containing the relevant info.
+func parseMDStat(mdStatData []byte) ([]MDStat, error) {
+	mdStats := []MDStat{}
+	lines := strings.Split(string(mdStatData), "\n")
+
+	for i, line := range lines {
+		if strings.TrimSpace(line) == "" || line[0] == ' ' ||
+			strings.HasPrefix(line, "Personalities") ||
+			strings.HasPrefix(line, "unused") {
 			continue
 		}
 
-		mainLine := strings.Split(l, " ")
-		if len(mainLine) < 3 {
-			return mdStates, fmt.Errorf("error parsing mdline: %s", l)
+		deviceFields := strings.Fields(line)
+		if len(deviceFields) < 3 {
+			return nil, fmt.Errorf("not enough fields in mdline (expected at least 3): %s", line)
 		}
-		mdName := mainLine[0]
-		activityState := mainLine[2]
+		mdName := deviceFields[0] // mdx
+		state := deviceFields[2]  // active or inactive
 
 		if len(lines) <= i+3 {
-			return mdStates, fmt.Errorf(
-				"error parsing %s: too few lines for md device %s",
-				mdStatusFilePath,
+			return nil, fmt.Errorf(
+				"error parsing %s: too few lines for md device",
 				mdName,
 			)
 		}
 
-		active, total, size, err := evalStatusline(lines[i+1])
+		// Failed disks have the suffix (F) & Spare disks have the suffix (S).
+		fail := int64(strings.Count(line, "(F)"))
+		spare := int64(strings.Count(line, "(S)"))
+		active, total, size, err := evalStatusLine(lines[i], lines[i+1])
+
 		if err != nil {
-			return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+			return nil, fmt.Errorf("error parsing md device lines: %s", err)
 		}
 
-		// j is the line number of the syncing-line.
-		j := i + 2
+		syncLineIdx := i + 2
 		if strings.Contains(lines[i+2], "bitmap") { // skip bitmap line
-			j = i + 3
+			syncLineIdx++
 		}
 
 		// If device is syncing at the moment, get the number of currently
 		// synced bytes, otherwise that number equals the size of the device.
 		syncedBlocks := size
-		if strings.Contains(lines[j], "recovery") || strings.Contains(lines[j], "resync") {
-			syncedBlocks, err = evalBuildline(lines[j])
-			if err != nil {
-				return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+		recovering := strings.Contains(lines[syncLineIdx], "recovery")
+		resyncing := strings.Contains(lines[syncLineIdx], "resync")
+
+		// Append recovery and resyncing state info.
+		if recovering || resyncing {
+			if recovering {
+				state = "recovering"
+			} else {
+				state = "resyncing"
+			}
+
+			// Handle case when resync=PENDING or resync=DELAYED.
+			if strings.Contains(lines[syncLineIdx], "PENDING") ||
+				strings.Contains(lines[syncLineIdx], "DELAYED") {
+				syncedBlocks = 0
+			} else {
+				syncedBlocks, err = evalRecoveryLine(lines[syncLineIdx])
+				if err != nil {
+					return nil, fmt.Errorf("error parsing sync line in md device %s: %s", mdName, err)
+				}
 			}
 		}
 
-		mdStates = append(mdStates, MDStat{
+		mdStats = append(mdStats, MDStat{
 			Name:          mdName,
-			ActivityState: activityState,
+			ActivityState: state,
 			DisksActive:   active,
+			DisksFailed:   fail,
+			DisksSpare:    spare,
 			DisksTotal:    total,
 			BlocksTotal:   size,
 			BlocksSynced:  syncedBlocks,
 		})
 	}
 
-	return mdStates, nil
+	return mdStats, nil
 }
 
-func evalStatusline(statusline string) (active, total, size int64, err error) {
-	matches := statuslineRE.FindStringSubmatch(statusline)
-	if len(matches) != 4 {
-		return 0, 0, 0, fmt.Errorf("unexpected statusline: %s", statusline)
+func evalStatusLine(deviceLine, statusLine string) (active, total, size int64, err error) {
+
+	sizeStr := strings.Fields(statusLine)[0]
+	size, err = strconv.ParseInt(sizeStr, 10, 64)
+	if err != nil {
+		return 0, 0, 0, fmt.Errorf("unexpected statusLine %s: %s", statusLine, err)
 	}
 
-	size, err = strconv.ParseInt(matches[1], 10, 64)
-	if err != nil {
-		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+	if strings.Contains(deviceLine, "raid0") || strings.Contains(deviceLine, "linear") {
+		// In the device deviceLine, only disks have a number associated with them in [].
+		total = int64(strings.Count(deviceLine, "["))
+		return total, total, size, nil
+	}
+
+	if strings.Contains(deviceLine, "inactive") {
+		return 0, 0, size, nil
+	}
+
+	matches := statusLineRE.FindStringSubmatch(statusLine)
+	if len(matches) != 4 {
+		return 0, 0, 0, fmt.Errorf("couldn't find all the substring matches: %s", statusLine)
 	}
 
 	total, err = strconv.ParseInt(matches[2], 10, 64)
 	if err != nil {
-		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+		return 0, 0, 0, fmt.Errorf("unexpected statusLine %s: %s", statusLine, err)
 	}
 
 	active, err = strconv.ParseInt(matches[3], 10, 64)
 	if err != nil {
-		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+		return 0, 0, 0, fmt.Errorf("unexpected statusLine %s: %s", statusLine, err)
 	}
 
 	return active, total, size, nil
 }
 
-func evalBuildline(buildline string) (syncedBlocks int64, err error) {
-	matches := buildlineRE.FindStringSubmatch(buildline)
+func evalRecoveryLine(recoveryLine string) (syncedBlocks int64, err error) {
+	matches := recoveryLineRE.FindStringSubmatch(recoveryLine)
 	if len(matches) != 2 {
-		return 0, fmt.Errorf("unexpected buildline: %s", buildline)
+		return 0, fmt.Errorf("unexpected recoveryLine: %s", recoveryLine)
 	}
 
 	syncedBlocks, err = strconv.ParseInt(matches[1], 10, 64)
 	if err != nil {
-		return 0, fmt.Errorf("%s in buildline: %s", err, buildline)
+		return 0, fmt.Errorf("%s in recoveryLine: %s", err, recoveryLine)
 	}
 
 	return syncedBlocks, nil

vendor/github.com/prometheus/procfs/mountinfo.go

@@ -0,0 +1,178 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var validOptionalFields = map[string]bool{
+	"shared":         true,
+	"master":         true,
+	"propagate_from": true,
+	"unbindable":     true,
+}
+
+// A MountInfo is a type that describes the details, options
+// for each mount, parsed from /proc/self/mountinfo.
+// The fields described in each entry of /proc/self/mountinfo
+// is described in the following man page.
+// http://man7.org/linux/man-pages/man5/proc.5.html
+type MountInfo struct {
+	// Unique Id for the mount
+	MountId int
+	// The Id of the parent mount
+	ParentId int
+	// The value of `st_dev` for the files on this FS
+	MajorMinorVer string
+	// The pathname of the directory in the FS that forms
+	// the root for this mount
+	Root string
+	// The pathname of the mount point relative to the root
+	MountPoint string
+	// Mount options
+	Options map[string]string
+	// Zero or more optional fields
+	OptionalFields map[string]string
+	// The Filesystem type
+	FSType string
+	// FS specific information or "none"
+	Source string
+	// Superblock options
+	SuperOptions map[string]string
+}
+
+// Returns part of the mountinfo line, if it exists, else an empty string.
+func getStringSliceElement(parts []string, idx int, defaultValue string) string {
+	if idx >= len(parts) {
+		return defaultValue
+	}
+	return parts[idx]
+}
+
+// Reads each line of the mountinfo file, and returns a list of formatted MountInfo structs.
+func parseMountInfo(r io.Reader) ([]*MountInfo, error) {
+	mounts := []*MountInfo{}
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		mountString := scanner.Text()
+		parsedMounts, err := parseMountInfoString(mountString)
+		if err != nil {
+			return nil, err
+		}
+		mounts = append(mounts, parsedMounts)
+	}
+
+	err := scanner.Err()
+	return mounts, err
+}
+
+// Parses a mountinfo file line, and converts it to a MountInfo struct.
+// An important check here is to see if the hyphen separator, as if it does not exist,
+// it means that the line is malformed.
+func parseMountInfoString(mountString string) (*MountInfo, error) {
+	var err error
+
+	// OptionalFields can be zero, hence these checks to ensure we do not populate the wrong values in the wrong spots
+	separatorIndex := strings.Index(mountString, "-")
+	if separatorIndex == -1 {
+		return nil, fmt.Errorf("no separator found in mountinfo string: %s", mountString)
+	}
+	beforeFields := strings.Fields(mountString[:separatorIndex])
+	afterFields := strings.Fields(mountString[separatorIndex+1:])
+	if (len(beforeFields) + len(afterFields)) < 7 {
+		return nil, fmt.Errorf("too few fields")
+	}
+
+	mount := &MountInfo{
+		MajorMinorVer:  getStringSliceElement(beforeFields, 2, ""),
+		Root:           getStringSliceElement(beforeFields, 3, ""),
+		MountPoint:     getStringSliceElement(beforeFields, 4, ""),
+		Options:        mountOptionsParser(getStringSliceElement(beforeFields, 5, "")),
+		OptionalFields: nil,
+		FSType:         getStringSliceElement(afterFields, 0, ""),
+		Source:         getStringSliceElement(afterFields, 1, ""),
+		SuperOptions:   mountOptionsParser(getStringSliceElement(afterFields, 2, "")),
+	}
+
+	mount.MountId, err = strconv.Atoi(getStringSliceElement(beforeFields, 0, ""))
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse mount ID")
+	}
+	mount.ParentId, err = strconv.Atoi(getStringSliceElement(beforeFields, 1, ""))
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse parent ID")
+	}
+	// Has optional fields, which is a space separated list of values.
+	// Example: shared:2 master:7
+	if len(beforeFields) > 6 {
+		mount.OptionalFields = make(map[string]string)
+		optionalFields := beforeFields[6:]
+		for _, field := range optionalFields {
+			optionSplit := strings.Split(field, ":")
+			target, value := optionSplit[0], ""
+			if len(optionSplit) == 2 {
+				value = optionSplit[1]
+			}
+			// Checks if the 'keys' in the optional fields in the mountinfo line are acceptable.
+			// Allowed 'keys' are shared, master, propagate_from, unbindable.
+			if _, ok := validOptionalFields[target]; ok {
+				mount.OptionalFields[target] = value
+			}
+		}
+	}
+	return mount, nil
+}
+
+// Parses the mount options, superblock options.
+func mountOptionsParser(mountOptions string) map[string]string {
+	opts := make(map[string]string)
+	options := strings.Split(mountOptions, ",")
+	for _, opt := range options {
+		splitOption := strings.Split(opt, "=")
+		if len(splitOption) < 2 {
+			key := splitOption[0]
+			opts[key] = ""
+		} else {
+			key, value := splitOption[0], splitOption[1]
+			opts[key] = value
+		}
+	}
+	return opts
+}
+
+// Retrieves mountinfo information from `/proc/self/mountinfo`.
+func GetMounts() ([]*MountInfo, error) {
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return parseMountInfo(f)
+}
+
+// Retrieves mountinfo information from a processes' `/proc/<pid>/mountinfo`.
+func GetProcMounts(pid int) ([]*MountInfo, error) {
+	f, err := os.Open(fmt.Sprintf("/proc/%d/mountinfo", pid))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return parseMountInfo(f)
+}

vendor/github.com/prometheus/procfs/mountstats.go

@@ -1,3 +1,16 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package procfs
 
 // While implementing parsing of /proc/[pid]/mountstats, this blog was used
@@ -26,8 +39,11 @@ const (
 	statVersion10 = "1.0"
 	statVersion11 = "1.1"
 
-	fieldTransport10Len = 10
-	fieldTransport11Len = 13
+	fieldTransport10TCPLen = 10
+	fieldTransport10UDPLen = 7
+
+	fieldTransport11TCPLen = 13
+	fieldTransport11UDPLen = 10
 )
 
 // A Mount is a device mount parsed from /proc/[pid]/mountstats.
@@ -53,6 +69,8 @@ type MountStats interface {
 type MountStatsNFS struct {
 	// The version of statistics provided.
 	StatVersion string
+	// The mount options of the NFS mount.
+	Opts map[string]string
 	// The age of the NFS mount.
 	Age time.Duration
 	// Statistics related to byte counters for various operations.
@@ -163,16 +181,18 @@ type NFSOperationStats struct {
 	// Number of bytes received for this operation, including RPC headers and payload.
 	BytesReceived uint64
 	// Duration all requests spent queued for transmission before they were sent.
-	CumulativeQueueTime time.Duration
+	CumulativeQueueMilliseconds uint64
 	// Duration it took to get a reply back after the request was transmitted.
-	CumulativeTotalResponseTime time.Duration
+	CumulativeTotalResponseMilliseconds uint64
 	// Duration from when a request was enqueued to when it was completely handled.
-	CumulativeTotalRequestTime time.Duration
+	CumulativeTotalRequestMilliseconds uint64
 }
 
 // A NFSTransportStats contains statistics for the NFS mount RPC requests and
 // responses.
 type NFSTransportStats struct {
+	// The transport protocol used for the NFS mount.
+	Protocol string
 	// The local port used for the NFS mount.
 	Port uint64
 	// Number of times the client has had to establish a connection from scratch
@@ -184,7 +204,7 @@ type NFSTransportStats struct {
 	// spent waiting for connections to the server to be established.
 	ConnectIdleTime uint64
 	// Duration since the NFS mount last saw any RPC traffic.
-	IdleTime time.Duration
+	IdleTimeSeconds uint64
 	// Number of RPC requests for this mount sent to the NFS server.
 	Sends uint64
 	// Number of RPC responses for this mount received from the NFS server.
@@ -299,6 +319,7 @@ func parseMount(ss []string) (*Mount, error) {
 func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, error) {
 	// Field indicators for parsing specific types of data
 	const (
+		fieldOpts       = "opts:"
 		fieldAge        = "age:"
 		fieldBytes      = "bytes:"
 		fieldEvents     = "events:"
@@ -320,6 +341,18 @@ func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, e
 		}
 
 		switch ss[0] {
+		case fieldOpts:
+			if stats.Opts == nil {
+				stats.Opts = map[string]string{}
+			}
+			for _, opt := range strings.Split(ss[1], ",") {
+				split := strings.Split(opt, "=")
+				if len(split) == 2 {
+					stats.Opts[split[0]] = split[1]
+				} else {
+					stats.Opts[opt] = ""
+				}
+			}
 		case fieldAge:
 			// Age integer is in seconds
 			d, err := time.ParseDuration(ss[1] + "s")
@@ -347,7 +380,7 @@ func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, e
 				return nil, fmt.Errorf("not enough information for NFS transport stats: %v", ss)
 			}
 
-			tstats, err := parseNFSTransportStats(ss[2:], statVersion)
+			tstats, err := parseNFSTransportStats(ss[1:], statVersion)
 			if err != nil {
 				return nil, err
 			}
@@ -491,15 +524,15 @@ func parseNFSOperationStats(s *bufio.Scanner) ([]NFSOperationStats, error) {
 		}
 
 		ops = append(ops, NFSOperationStats{
-			Operation:                   strings.TrimSuffix(ss[0], ":"),
-			Requests:                    ns[0],
-			Transmissions:               ns[1],
-			MajorTimeouts:               ns[2],
-			BytesSent:                   ns[3],
-			BytesReceived:               ns[4],
-			CumulativeQueueTime:         time.Duration(ns[5]) * time.Millisecond,
-			CumulativeTotalResponseTime: time.Duration(ns[6]) * time.Millisecond,
-			CumulativeTotalRequestTime:  time.Duration(ns[7]) * time.Millisecond,
+			Operation:                           strings.TrimSuffix(ss[0], ":"),
+			Requests:                            ns[0],
+			Transmissions:                       ns[1],
+			MajorTimeouts:                       ns[2],
+			BytesSent:                           ns[3],
+			BytesReceived:                       ns[4],
+			CumulativeQueueMilliseconds:         ns[5],
+			CumulativeTotalResponseMilliseconds: ns[6],
+			CumulativeTotalRequestMilliseconds:  ns[7],
 		})
 	}
 
@@ -509,13 +542,33 @@ func parseNFSOperationStats(s *bufio.Scanner) ([]NFSOperationStats, error) {
 // parseNFSTransportStats parses a NFSTransportStats line using an input set of
 // integer fields matched to a specific stats version.
 func parseNFSTransportStats(ss []string, statVersion string) (*NFSTransportStats, error) {
+	// Extract the protocol field. It is the only string value in the line
+	protocol := ss[0]
+	ss = ss[1:]
+
 	switch statVersion {
 	case statVersion10:
-		if len(ss) != fieldTransport10Len {
+		var expectedLength int
+		if protocol == "tcp" {
+			expectedLength = fieldTransport10TCPLen
+		} else if protocol == "udp" {
+			expectedLength = fieldTransport10UDPLen
+		} else {
+			return nil, fmt.Errorf("invalid NFS protocol \"%s\" in stats 1.0 statement: %v", protocol, ss)
+		}
+		if len(ss) != expectedLength {
 			return nil, fmt.Errorf("invalid NFS transport stats 1.0 statement: %v", ss)
 		}
 	case statVersion11:
-		if len(ss) != fieldTransport11Len {
+		var expectedLength int
+		if protocol == "tcp" {
+			expectedLength = fieldTransport11TCPLen
+		} else if protocol == "udp" {
+			expectedLength = fieldTransport11UDPLen
+		} else {
+			return nil, fmt.Errorf("invalid NFS protocol \"%s\" in stats 1.1 statement: %v", protocol, ss)
+		}
+		if len(ss) != expectedLength {
 			return nil, fmt.Errorf("invalid NFS transport stats 1.1 statement: %v", ss)
 		}
 	default:
@@ -523,23 +576,39 @@ func parseNFSTransportStats(ss []string, statVersion string) (*NFSTransportStats
 	}
 
 	// Allocate enough for v1.1 stats since zero value for v1.1 stats will be okay
-	// in a v1.0 response
-	ns := make([]uint64, 0, fieldTransport11Len)
-	for _, s := range ss {
+	// in a v1.0 response. Since the stat length is bigger for TCP stats, we use
+	// the TCP length here.
+	//
+	// Note: slice length must be set to length of v1.1 stats to avoid a panic when
+	// only v1.0 stats are present.
+	// See: https://github.com/prometheus/node_exporter/issues/571.
+	ns := make([]uint64, fieldTransport11TCPLen)
+	for i, s := range ss {
 		n, err := strconv.ParseUint(s, 10, 64)
 		if err != nil {
 			return nil, err
 		}
 
-		ns = append(ns, n)
+		ns[i] = n
+	}
+
+	// The fields differ depending on the transport protocol (TCP or UDP)
+	// From https://utcc.utoronto.ca/%7Ecks/space/blog/linux/NFSMountstatsXprt
+	//
+	// For the udp RPC transport there is no connection count, connect idle time,
+	// or idle time (fields #3, #4, and #5); all other fields are the same. So
+	// we set them to 0 here.
+	if protocol == "udp" {
+		ns = append(ns[:2], append(make([]uint64, 3), ns[2:]...)...)
 	}
 
 	return &NFSTransportStats{
+		Protocol:                 protocol,
 		Port:                     ns[0],
 		Bind:                     ns[1],
 		Connect:                  ns[2],
 		ConnectIdleTime:          ns[3],
-		IdleTime:                 time.Duration(ns[4]) * time.Second,
+		IdleTimeSeconds:          ns[4],
 		Sends:                    ns[5],
 		Receives:                 ns[6],
 		BadTransactionIDs:        ns[7],

vendor/github.com/prometheus/procfs/net_dev.go

@@ -0,0 +1,206 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"errors"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// NetDevLine is single line parsed from /proc/net/dev or /proc/[pid]/net/dev.
+type NetDevLine struct {
+	Name         string `json:"name"`          // The name of the interface.
+	RxBytes      uint64 `json:"rx_bytes"`      // Cumulative count of bytes received.
+	RxPackets    uint64 `json:"rx_packets"`    // Cumulative count of packets received.
+	RxErrors     uint64 `json:"rx_errors"`     // Cumulative count of receive errors encountered.
+	RxDropped    uint64 `json:"rx_dropped"`    // Cumulative count of packets dropped while receiving.
+	RxFIFO       uint64 `json:"rx_fifo"`       // Cumulative count of FIFO buffer errors.
+	RxFrame      uint64 `json:"rx_frame"`      // Cumulative count of packet framing errors.
+	RxCompressed uint64 `json:"rx_compressed"` // Cumulative count of compressed packets received by the device driver.
+	RxMulticast  uint64 `json:"rx_multicast"`  // Cumulative count of multicast frames received by the device driver.
+	TxBytes      uint64 `json:"tx_bytes"`      // Cumulative count of bytes transmitted.
+	TxPackets    uint64 `json:"tx_packets"`    // Cumulative count of packets transmitted.
+	TxErrors     uint64 `json:"tx_errors"`     // Cumulative count of transmit errors encountered.
+	TxDropped    uint64 `json:"tx_dropped"`    // Cumulative count of packets dropped while transmitting.
+	TxFIFO       uint64 `json:"tx_fifo"`       // Cumulative count of FIFO buffer errors.
+	TxCollisions uint64 `json:"tx_collisions"` // Cumulative count of collisions detected on the interface.
+	TxCarrier    uint64 `json:"tx_carrier"`    // Cumulative count of carrier losses detected by the device driver.
+	TxCompressed uint64 `json:"tx_compressed"` // Cumulative count of compressed packets transmitted by the device driver.
+}
+
+// NetDev is parsed from /proc/net/dev or /proc/[pid]/net/dev. The map keys
+// are interface names.
+type NetDev map[string]NetDevLine
+
+// NetDev returns kernel/system statistics read from /proc/net/dev.
+func (fs FS) NetDev() (NetDev, error) {
+	return newNetDev(fs.proc.Path("net/dev"))
+}
+
+// NetDev returns kernel/system statistics read from /proc/[pid]/net/dev.
+func (p Proc) NetDev() (NetDev, error) {
+	return newNetDev(p.path("net/dev"))
+}
+
+// newNetDev creates a new NetDev from the contents of the given file.
+func newNetDev(file string) (NetDev, error) {
+	f, err := os.Open(file)
+	if err != nil {
+		return NetDev{}, err
+	}
+	defer f.Close()
+
+	netDev := NetDev{}
+	s := bufio.NewScanner(f)
+	for n := 0; s.Scan(); n++ {
+		// Skip the 2 header lines.
+		if n < 2 {
+			continue
+		}
+
+		line, err := netDev.parseLine(s.Text())
+		if err != nil {
+			return netDev, err
+		}
+
+		netDev[line.Name] = *line
+	}
+
+	return netDev, s.Err()
+}
+
+// parseLine parses a single line from the /proc/net/dev file. Header lines
+// must be filtered prior to calling this method.
+func (netDev NetDev) parseLine(rawLine string) (*NetDevLine, error) {
+	parts := strings.SplitN(rawLine, ":", 2)
+	if len(parts) != 2 {
+		return nil, errors.New("invalid net/dev line, missing colon")
+	}
+	fields := strings.Fields(strings.TrimSpace(parts[1]))
+
+	var err error
+	line := &NetDevLine{}
+
+	// Interface Name
+	line.Name = strings.TrimSpace(parts[0])
+	if line.Name == "" {
+		return nil, errors.New("invalid net/dev line, empty interface name")
+	}
+
+	// RX
+	line.RxBytes, err = strconv.ParseUint(fields[0], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.RxPackets, err = strconv.ParseUint(fields[1], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.RxErrors, err = strconv.ParseUint(fields[2], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.RxDropped, err = strconv.ParseUint(fields[3], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.RxFIFO, err = strconv.ParseUint(fields[4], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.RxFrame, err = strconv.ParseUint(fields[5], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.RxCompressed, err = strconv.ParseUint(fields[6], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.RxMulticast, err = strconv.ParseUint(fields[7], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+
+	// TX
+	line.TxBytes, err = strconv.ParseUint(fields[8], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.TxPackets, err = strconv.ParseUint(fields[9], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.TxErrors, err = strconv.ParseUint(fields[10], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.TxDropped, err = strconv.ParseUint(fields[11], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.TxFIFO, err = strconv.ParseUint(fields[12], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.TxCollisions, err = strconv.ParseUint(fields[13], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.TxCarrier, err = strconv.ParseUint(fields[14], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+	line.TxCompressed, err = strconv.ParseUint(fields[15], 10, 64)
+	if err != nil {
+		return nil, err
+	}
+
+	return line, nil
+}
+
+// Total aggregates the values across interfaces and returns a new NetDevLine.
+// The Name field will be a sorted comma separated list of interface names.
+func (netDev NetDev) Total() NetDevLine {
+	total := NetDevLine{}
+
+	names := make([]string, 0, len(netDev))
+	for _, ifc := range netDev {
+		names = append(names, ifc.Name)
+		total.RxBytes += ifc.RxBytes
+		total.RxPackets += ifc.RxPackets
+		total.RxPackets += ifc.RxPackets
+		total.RxErrors += ifc.RxErrors
+		total.RxDropped += ifc.RxDropped
+		total.RxFIFO += ifc.RxFIFO
+		total.RxFrame += ifc.RxFrame
+		total.RxCompressed += ifc.RxCompressed
+		total.RxMulticast += ifc.RxMulticast
+		total.TxBytes += ifc.TxBytes
+		total.TxPackets += ifc.TxPackets
+		total.TxErrors += ifc.TxErrors
+		total.TxDropped += ifc.TxDropped
+		total.TxFIFO += ifc.TxFIFO
+		total.TxCollisions += ifc.TxCollisions
+		total.TxCarrier += ifc.TxCarrier
+		total.TxCompressed += ifc.TxCompressed
+	}
+	sort.Strings(names)
+	total.Name = strings.Join(names, ", ")
+
+	return total
+}

vendor/github.com/prometheus/procfs/net_unix.go

@@ -0,0 +1,275 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// For the proc file format details,
+// see https://elixir.bootlin.com/linux/v4.17/source/net/unix/af_unix.c#L2815
+// and https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/net.h#L48.
+
+const (
+	netUnixKernelPtrIdx = iota
+	netUnixRefCountIdx
+	_
+	netUnixFlagsIdx
+	netUnixTypeIdx
+	netUnixStateIdx
+	netUnixInodeIdx
+
+	// Inode and Path are optional.
+	netUnixStaticFieldsCnt = 6
+)
+
+const (
+	netUnixTypeStream    = 1
+	netUnixTypeDgram     = 2
+	netUnixTypeSeqpacket = 5
+
+	netUnixFlagListen = 1 << 16
+
+	netUnixStateUnconnected  = 1
+	netUnixStateConnecting   = 2
+	netUnixStateConnected    = 3
+	netUnixStateDisconnected = 4
+)
+
+var errInvalidKernelPtrFmt = errors.New("Invalid Num(the kernel table slot number) format")
+
+// NetUnixType is the type of the type field.
+type NetUnixType uint64
+
+// NetUnixFlags is the type of the flags field.
+type NetUnixFlags uint64
+
+// NetUnixState is the type of the state field.
+type NetUnixState uint64
+
+// NetUnixLine represents a line of /proc/net/unix.
+type NetUnixLine struct {
+	KernelPtr string
+	RefCount  uint64
+	Protocol  uint64
+	Flags     NetUnixFlags
+	Type      NetUnixType
+	State     NetUnixState
+	Inode     uint64
+	Path      string
+}
+
+// NetUnix holds the data read from /proc/net/unix.
+type NetUnix struct {
+	Rows []*NetUnixLine
+}
+
+// NewNetUnix returns data read from /proc/net/unix.
+func NewNetUnix() (*NetUnix, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return nil, err
+	}
+
+	return fs.NewNetUnix()
+}
+
+// NewNetUnix returns data read from /proc/net/unix.
+func (fs FS) NewNetUnix() (*NetUnix, error) {
+	return NewNetUnixByPath(fs.proc.Path("net/unix"))
+}
+
+// NewNetUnixByPath returns data read from /proc/net/unix by file path.
+// It might returns an error with partial parsed data, if an error occur after some data parsed.
+func NewNetUnixByPath(path string) (*NetUnix, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return NewNetUnixByReader(f)
+}
+
+// NewNetUnixByReader returns data read from /proc/net/unix by a reader.
+// It might returns an error with partial parsed data, if an error occur after some data parsed.
+func NewNetUnixByReader(reader io.Reader) (*NetUnix, error) {
+	nu := &NetUnix{
+		Rows: make([]*NetUnixLine, 0, 32),
+	}
+	scanner := bufio.NewScanner(reader)
+	// Omit the header line.
+	scanner.Scan()
+	header := scanner.Text()
+	// From the man page of proc(5), it does not contain an Inode field,
+	// but in actually it exists.
+	// This code works for both cases.
+	hasInode := strings.Contains(header, "Inode")
+
+	minFieldsCnt := netUnixStaticFieldsCnt
+	if hasInode {
+		minFieldsCnt++
+	}
+	for scanner.Scan() {
+		line := scanner.Text()
+		item, err := nu.parseLine(line, hasInode, minFieldsCnt)
+		if err != nil {
+			return nu, err
+		}
+		nu.Rows = append(nu.Rows, item)
+	}
+
+	return nu, scanner.Err()
+}
+
+func (u *NetUnix) parseLine(line string, hasInode bool, minFieldsCnt int) (*NetUnixLine, error) {
+	fields := strings.Fields(line)
+	fieldsLen := len(fields)
+	if fieldsLen < minFieldsCnt {
+		return nil, fmt.Errorf(
+			"Parse Unix domain failed: expect at least %d fields but got %d",
+			minFieldsCnt, fieldsLen)
+	}
+	kernelPtr, err := u.parseKernelPtr(fields[netUnixKernelPtrIdx])
+	if err != nil {
+		return nil, fmt.Errorf("Parse Unix domain num(%s) failed: %s", fields[netUnixKernelPtrIdx], err)
+	}
+	users, err := u.parseUsers(fields[netUnixRefCountIdx])
+	if err != nil {
+		return nil, fmt.Errorf("Parse Unix domain ref count(%s) failed: %s", fields[netUnixRefCountIdx], err)
+	}
+	flags, err := u.parseFlags(fields[netUnixFlagsIdx])
+	if err != nil {
+		return nil, fmt.Errorf("Parse Unix domain flags(%s) failed: %s", fields[netUnixFlagsIdx], err)
+	}
+	typ, err := u.parseType(fields[netUnixTypeIdx])
+	if err != nil {
+		return nil, fmt.Errorf("Parse Unix domain type(%s) failed: %s", fields[netUnixTypeIdx], err)
+	}
+	state, err := u.parseState(fields[netUnixStateIdx])
+	if err != nil {
+		return nil, fmt.Errorf("Parse Unix domain state(%s) failed: %s", fields[netUnixStateIdx], err)
+	}
+	var inode uint64
+	if hasInode {
+		inodeStr := fields[netUnixInodeIdx]
+		inode, err = u.parseInode(inodeStr)
+		if err != nil {
+			return nil, fmt.Errorf("Parse Unix domain inode(%s) failed: %s", inodeStr, err)
+		}
+	}
+
+	nuLine := &NetUnixLine{
+		KernelPtr: kernelPtr,
+		RefCount:  users,
+		Type:      typ,
+		Flags:     flags,
+		State:     state,
+		Inode:     inode,
+	}
+
+	// Path field is optional.
+	if fieldsLen > minFieldsCnt {
+		pathIdx := netUnixInodeIdx + 1
+		if !hasInode {
+			pathIdx--
+		}
+		nuLine.Path = fields[pathIdx]
+	}
+
+	return nuLine, nil
+}
+
+func (u NetUnix) parseKernelPtr(str string) (string, error) {
+	if !strings.HasSuffix(str, ":") {
+		return "", errInvalidKernelPtrFmt
+	}
+	return str[:len(str)-1], nil
+}
+
+func (u NetUnix) parseUsers(hexStr string) (uint64, error) {
+	return strconv.ParseUint(hexStr, 16, 32)
+}
+
+func (u NetUnix) parseProtocol(hexStr string) (uint64, error) {
+	return strconv.ParseUint(hexStr, 16, 32)
+}
+
+func (u NetUnix) parseType(hexStr string) (NetUnixType, error) {
+	typ, err := strconv.ParseUint(hexStr, 16, 16)
+	if err != nil {
+		return 0, err
+	}
+	return NetUnixType(typ), nil
+}
+
+func (u NetUnix) parseFlags(hexStr string) (NetUnixFlags, error) {
+	flags, err := strconv.ParseUint(hexStr, 16, 32)
+	if err != nil {
+		return 0, err
+	}
+	return NetUnixFlags(flags), nil
+}
+
+func (u NetUnix) parseState(hexStr string) (NetUnixState, error) {
+	st, err := strconv.ParseInt(hexStr, 16, 8)
+	if err != nil {
+		return 0, err
+	}
+	return NetUnixState(st), nil
+}
+
+func (u NetUnix) parseInode(inodeStr string) (uint64, error) {
+	return strconv.ParseUint(inodeStr, 10, 64)
+}
+
+func (t NetUnixType) String() string {
+	switch t {
+	case netUnixTypeStream:
+		return "stream"
+	case netUnixTypeDgram:
+		return "dgram"
+	case netUnixTypeSeqpacket:
+		return "seqpacket"
+	}
+	return "unknown"
+}
+
+func (f NetUnixFlags) String() string {
+	switch f {
+	case netUnixFlagListen:
+		return "listen"
+	default:
+		return "default"
+	}
+}
+
+func (s NetUnixState) String() string {
+	switch s {
+	case netUnixStateUnconnected:
+		return "unconnected"
+	case netUnixStateConnecting:
+		return "connecting"
+	case netUnixStateConnected:
+		return "connected"
+	case netUnixStateDisconnected:
+		return "disconnected"
+	}
+	return "unknown"
+}

vendor/github.com/prometheus/procfs/proc.go

@@ -1,11 +1,27 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package procfs
 
 import (
+	"bytes"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"strconv"
 	"strings"
+
+	"github.com/prometheus/procfs/internal/fs"
 )
 
 // Proc provides information about a running process.
@@ -13,7 +29,7 @@ type Proc struct {
 	// The process ID.
 	PID int
 
-	fs FS
+	fs fs.FS
 }
 
 // Procs represents a list of Proc structs.
@@ -38,7 +54,7 @@ func NewProc(pid int) (Proc, error) {
 	if err != nil {
 		return Proc{}, err
 	}
-	return fs.NewProc(pid)
+	return fs.Proc(pid)
 }
 
 // AllProcs returns a list of all currently available processes under /proc.
@@ -52,28 +68,35 @@ func AllProcs() (Procs, error) {
 
 // Self returns a process for the current process.
 func (fs FS) Self() (Proc, error) {
-	p, err := os.Readlink(fs.Path("self"))
+	p, err := os.Readlink(fs.proc.Path("self"))
 	if err != nil {
 		return Proc{}, err
 	}
-	pid, err := strconv.Atoi(strings.Replace(p, string(fs), "", -1))
+	pid, err := strconv.Atoi(strings.Replace(p, string(fs.proc), "", -1))
 	if err != nil {
 		return Proc{}, err
 	}
-	return fs.NewProc(pid)
+	return fs.Proc(pid)
 }
 
 // NewProc returns a process for the given pid.
+//
+// Deprecated: use fs.Proc() instead
 func (fs FS) NewProc(pid int) (Proc, error) {
-	if _, err := os.Stat(fs.Path(strconv.Itoa(pid))); err != nil {
+	return fs.Proc(pid)
+}
+
+// Proc returns a process for the given pid.
+func (fs FS) Proc(pid int) (Proc, error) {
+	if _, err := os.Stat(fs.proc.Path(strconv.Itoa(pid))); err != nil {
 		return Proc{}, err
 	}
-	return Proc{PID: pid, fs: fs}, nil
+	return Proc{PID: pid, fs: fs.proc}, nil
 }
 
 // AllProcs returns a list of all currently available processes.
 func (fs FS) AllProcs() (Procs, error) {
-	d, err := os.Open(fs.Path())
+	d, err := os.Open(fs.proc.Path())
 	if err != nil {
 		return Procs{}, err
 	}
@@ -90,7 +113,7 @@ func (fs FS) AllProcs() (Procs, error) {
 		if err != nil {
 			continue
 		}
-		p = append(p, Proc{PID: int(pid), fs: fs})
+		p = append(p, Proc{PID: int(pid), fs: fs.proc})
 	}
 
 	return p, nil
@@ -113,7 +136,7 @@ func (p Proc) CmdLine() ([]string, error) {
 		return []string{}, nil
 	}
 
-	return strings.Split(string(data[:len(data)-1]), string(byte(0))), nil
+	return strings.Split(string(bytes.TrimRight(data, string("\x00"))), string(byte(0))), nil
 }
 
 // Comm returns the command name of a process.
@@ -142,6 +165,26 @@ func (p Proc) Executable() (string, error) {
 	return exe, err
 }
 
+// Cwd returns the absolute path to the current working directory of the process.
+func (p Proc) Cwd() (string, error) {
+	wd, err := os.Readlink(p.path("cwd"))
+	if os.IsNotExist(err) {
+		return "", nil
+	}
+
+	return wd, err
+}
+
+// RootDir returns the absolute path to the process's root directory (as set by chroot)
+func (p Proc) RootDir() (string, error) {
+	rdir, err := os.Readlink(p.path("root"))
+	if os.IsNotExist(err) {
+		return "", nil
+	}
+
+	return rdir, err
+}
+
 // FileDescriptors returns the currently open file descriptors of a process.
 func (p Proc) FileDescriptors() ([]uintptr, error) {
 	names, err := p.fileDescriptors()
@@ -204,6 +247,20 @@ func (p Proc) MountStats() ([]*Mount, error) {
 	return parseMountStats(f)
 }
 
+// MountInfo retrieves mount information for mount points in a
+// process's namespace.
+// It supplies information missing in `/proc/self/mounts` and
+// fixes various other problems with that file too.
+func (p Proc) MountInfo() ([]*MountInfo, error) {
+	f, err := os.Open(p.path("mountinfo"))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return parseMountInfo(f)
+}
+
 func (p Proc) fileDescriptors() ([]string, error) {
 	d, err := os.Open(p.path("fd"))
 	if err != nil {