Add support to send DataDog traces via Unix Socket

docs/content/observability/tracing/datadog.md

@@ -23,24 +23,46 @@ tracing:
 
 #### `localAgentHostPort`
 
-_Required, Default="127.0.0.1:8126"_
+_Optional, Default="localhost:8126"_
 
 Local Agent Host Port instructs the reporter to send spans to the Datadog Agent at this address (host:port).
 
 ```yaml tab="File (YAML)"
 tracing:
   datadog:
-    localAgentHostPort: 127.0.0.1:8126
+    localAgentHostPort: localhost:8126
 ```
 
 ```toml tab="File (TOML)"
 [tracing]
   [tracing.datadog]
-    localAgentHostPort = "127.0.0.1:8126"
+    localAgentHostPort = "localhost:8126"
 ```
 
 ```bash tab="CLI"
---tracing.datadog.localAgentHostPort=127.0.0.1:8126
+--tracing.datadog.localAgentHostPort=localhost:8126
+```
+
+#### `localAgentSocket`
+
+_Optional, Default=""_
+
+Local Agent Socket instructs the reporter to send spans to the Datadog Agent at this UNIX socket.
+
+```yaml tab="File (YAML)"
+tracing:
+  datadog:
+    localAgentSocket: /var/run/datadog/apm.socket
+```
+
+```toml tab="File (TOML)"
+[tracing]
+  [tracing.datadog]
+    localAgentSocket = "/var/run/datadog/apm.socket"
+```
+
+```bash tab="CLI"
+--tracing.datadog.localAgentSocket=/var/run/datadog/apm.socket
 ```
 
 #### `debug`

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

@@ -990,6 +990,9 @@ Sets a list of key:value tags on all spans.
 `--tracing.datadog.localagenthostport`:  
 Sets the Datadog Agent host:port. (Default: ```localhost:8126```)
 
+`--tracing.datadog.localagentsocket`:  
+Sets the socket for the Datadog Agent.
+
 `--tracing.datadog.parentidheadername`:  
 Sets the header name used to store the parent ID.
 

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

@@ -990,6 +990,9 @@ Sets a list of key:value tags on all spans.
 `TRAEFIK_TRACING_DATADOG_LOCALAGENTHOSTPORT`:  
 Sets the Datadog Agent host:port. (Default: ```localhost:8126```)
 
+`TRAEFIK_TRACING_DATADOG_LOCALAGENTSOCKET`:  
+Sets the socket for the Datadog Agent.
+
 `TRAEFIK_TRACING_DATADOG_PARENTIDHEADERNAME`:  
 Sets the header name used to store the parent ID.
 

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

@@ -365,6 +365,7 @@
     sampleRate = 42.0
   [tracing.datadog]
     localAgentHostPort = "foobar"
+    localAgentSocket = "foobar"
     globalTag = "foobar"
     [tracing.datadog.globalTags]
       tag1 = "foobar"

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

@@ -389,6 +389,7 @@ tracing:
     sampleRate: 42
   datadog:
     localAgentHostPort: foobar
+    localAgentSocket: foobar
     globalTag: foobar
     globalTags:
       tag1: foobar

pkg/config/dynamic/fixtures/sample.toml

@@ -171,6 +171,7 @@
     samplingType = "foobar"
     samplingParam = 42.0
     localAgentHostPort = "foobar"
+    localAgentSocket = "foobar"
     gen128Bit = true
     propagation = "foobar"
     traceContextHeaderName = "foobar"
@@ -182,6 +183,7 @@
     sampleRate = 42.0
   [tracing.datadog]
     localAgentHostPort = "foobar"
+    localAgentSocket = "foobar"
     globalTag = "foobar"
     debug = true
     prioritySampling = true

pkg/redactor/redactor_config_test.go

@@ -899,6 +899,7 @@ func TestDo_staticConfiguration(t *testing.T) {
 		},
 		Datadog: &datadog.Config{
 			LocalAgentHostPort:         "foobar",
+			LocalAgentSocket:           "foobar",
 			GlobalTag:                  "foobar",
 			Debug:                      true,
 			PrioritySampling:           true,

pkg/redactor/testdata/anonymized-static-config.json

@@ -390,6 +390,7 @@
     },
     "datadog": {
       "localAgentHostPort": "xxxx",
+      "localAgentSocket": "xxxx",
       "globalTag": "foobar",
       "debug": true,
       "prioritySampling": true,

pkg/tracing/datadog/datadog.go

@@ -18,6 +18,7 @@ const Name = "datadog"
 // Config provides configuration settings for a datadog tracer.
 type Config struct {
 	LocalAgentHostPort string `description:"Sets the Datadog Agent host:port." json:"localAgentHostPort,omitempty" toml:"localAgentHostPort,omitempty" yaml:"localAgentHostPort,omitempty"`
+	LocalAgentSocket   string `description:"Sets the socket for the Datadog Agent." json:"localAgentSocket,omitempty" toml:"localAgentSocket,omitempty" yaml:"localAgentSocket,omitempty"`
 	// Deprecated: use GlobalTags instead.
 	GlobalTag                  string            `description:"Sets a key:value tag on all spans." json:"globalTag,omitempty" toml:"globalTag,omitempty" yaml:"globalTag,omitempty" export:"true"`
 	GlobalTags                 map[string]string `description:"Sets a list of key:value tags on all spans." json:"globalTags,omitempty" toml:"globalTags,omitempty" yaml:"globalTags,omitempty" export:"true"`
@@ -47,7 +48,6 @@ func (c *Config) SetDefaults() {
 // Setup sets up the tracer.
 func (c *Config) Setup(serviceName string) (opentracing.Tracer, io.Closer, error) {
 	opts := []datadog.StartOption{
-		datadog.WithAgentAddr(c.LocalAgentHostPort),
 		datadog.WithServiceName(serviceName),
 		datadog.WithDebugMode(c.Debug),
 		datadog.WithPropagator(datadog.NewPropagator(&datadog.PropagatorConfig{
@@ -58,6 +58,12 @@ func (c *Config) Setup(serviceName string) (opentracing.Tracer, io.Closer, error
 		})),
 	}
 
+	if c.LocalAgentSocket != "" {
+		opts = append(opts, datadog.WithUDS(c.LocalAgentSocket))
+	} else {
+		opts = append(opts, datadog.WithAgentAddr(c.LocalAgentHostPort))
+	}
+
 	for k, v := range c.GlobalTags {
 		opts = append(opts, datadog.WithGlobalTag(k, v))
 	}