Merge pull request #701 from containous/carry-pr-446

Carry PR 446 - Add sticky session support (round two!)

docs/basics.md

@@ -222,6 +222,17 @@ For example:
 - Another possible value for `extractorfunc` is `client.ip` which will categorize requests based on client source ip.
 - Lastly `extractorfunc` can take the value of `request.header.ANY_HEADER` which will categorize requests based on `ANY_HEADER` that you provide.
 
+Sticky sessions are supported with both load balancers. When sticky sessions are enabled, a cookie called `_TRAEFIK_BACKEND` is set on the initial
+request. On subsequent requests, the client will be directed to the backend stored in the cookie if it is still healthy. If not, a new backend
+will be assigned.
+
+For example:
+```toml
+[backends]
+  [backends.backend1]
+    [backends.backend1.loadbalancer]
+      sticky = true
+```
 ## Servers
 
 Servers are simply defined using a `URL`. You can also apply a custom `weight` to each server (this will be used by load-balancing).

docs/toml.md

@@ -711,6 +711,7 @@ Labels can be used on containers to override default behaviour:
 - `traefik.backend.maxconn.amount=10`: set a maximum number of connections to the backend. Must be used in conjunction with the below label to take effect.
 - `traefik.backend.maxconn.extractorfunc=client.ip`: set the function to be used against the request to determine what to limit maximum connections to the backend by. Must be used in conjunction with the above label to take effect.
 - `traefik.backend.loadbalancer.method=drr`: override the default `wrr` load balancer algorithm
+- `traefik.backend.loadbalancer.sticky=true`: enable backend sticky sessions
 - `traefik.backend.circuitbreaker.expression=NetworkErrorRatio() > 0.5`: create a [circuit breaker](/basics/#backends) to be used against the backend
 - `traefik.port=80`: register this port. Useful when the container exposes multiples ports.
 - `traefik.protocol=https`: override the default `http` protocol
@@ -810,6 +811,7 @@ Labels can be used on containers to override default behaviour:
 - `traefik.backend.maxconn.amount=10`: set a maximum number of connections to the backend. Must be used in conjunction with the below label to take effect.
 - `traefik.backend.maxconn.extractorfunc=client.ip`: set the function to be used against the request to determine what to limit maximum connections to the backend by. Must be used in conjunction with the above label to take effect.
 - `traefik.backend.loadbalancer.method=drr`: override the default `wrr` load balancer algorithm
+- `traefik.backend.loadbalancer.sticky=true`: enable backend sticky sessions
 - `traefik.backend.circuitbreaker.expression=NetworkErrorRatio() > 0.5`: create a [circuit breaker](/basics/#backends) to be used against the backend
 - `traefik.portIndex=1`: register port by index in the application's ports array. Useful when the application exposes multiple ports.
 - `traefik.port=80`: register the explicit application port value. Cannot be used alongside `traefik.portIndex`.

glide.lock

@@ -1,10 +1,10 @@
 hash: c0ac205a859d78847e21d3cd63f427ffba985755c6ae84373e4a20364ba39b05
-updated: 2016-09-28T16:50:04.352639437+01:00
+updated: 2016-09-30T10:57:42.336729457+02:00
 imports:
 - name: github.com/abbot/go-http-auth
   version: cb4372376e1e00e9f6ab9ec142e029302c9e7140
 - name: github.com/boltdb/bolt
-  version: fff57c100f4dea1905678da7e90d92429dff2904
+  version: 5cc10bbbc5c141029940133bb33c9e969512a698
 - name: github.com/BurntSushi/toml
   version: 99064174e013895bbd9b025c31100bd1d9b590ca
 - name: github.com/BurntSushi/ty
@@ -18,7 +18,7 @@ imports:
 - name: github.com/codegangsta/cli
   version: 1efa31f08b9333f1bd4882d61f9d668a70cd902e
 - name: github.com/codegangsta/negroni
-  version: 3f7ce7b928e14ff890b067e5bbbc80af73690a9c
+  version: dc6b9d037e8dab60cbfc09c61d6932537829be8b
 - name: github.com/containous/flaeg
   version: a731c034dda967333efce5f8d276aeff11f8ff87
 - name: github.com/containous/mux
@@ -32,11 +32,11 @@ imports:
   - pkg/pathutil
   - pkg/types
 - name: github.com/davecgh/go-spew
-  version: 6d212800a42e8ab5c146b8ace3490ee17e5225f9
+  version: 5215b55f46b2b919f50a1df0eaa5886afe4e3b3d
   subpackages:
   - spew
 - name: github.com/docker/distribution
-  version: 99cb7c0946d2f5a38015443e515dc916295064d7
+  version: 87917f30529e6a7fca8eaff2932424915fb11225
   subpackages:
   - context
   - digest
@@ -116,13 +116,13 @@ imports:
   - types/time
   - types/versions
 - name: github.com/docker/go-connections
-  version: 988efe982fdecb46f01d53465878ff1f2ff411ce
+  version: 990a1a1a70b0da4c4cb70e117971a4f0babfbf1a
   subpackages:
   - nat
   - sockets
   - tlsconfig
 - name: github.com/docker/go-units
-  version: f2145db703495b2e525c59662db69a7344b00bb8
+  version: f2d77a61e3c169b43402a0a1e84f06daf29b8190
 - name: github.com/docker/libcompose
   version: d1876c1d68527a49c0aac22a0b161acc7296b740
   subpackages:
@@ -141,7 +141,7 @@ imports:
   - version
   - yaml
 - name: github.com/docker/libkv
-  version: 3fce6a0f26e07da3eac45796a8e255547a47a750
+  version: 35d3e2084c650109e7bcc7282655b1bc8ba924ff
   subpackages:
   - store
   - store/boltdb
@@ -151,13 +151,13 @@ imports:
 - name: github.com/donovanhide/eventsource
   version: fd1de70867126402be23c306e1ce32828455d85b
 - name: github.com/elazarl/go-bindata-assetfs
-  version: 9a6736ed45b44bf3835afeebb3034b57ed329f3e
+  version: 57eb5e1fc594ad4b0b1dbea7b286d299e0cb43c2
 - name: github.com/gambol99/go-marathon
   version: a558128c87724cd7430060ef5aedf39f83937f55
 - name: github.com/go-check/check
-  version: 11d3bc7aa68e238947792f30573146a3231fc0f1
+  version: 4f90aeace3a26ad7021961c297b22c42160c7b25
 - name: github.com/gogo/protobuf
-  version: 89f1976ff373a3e549675d2f212c10f98b6c6316
+  version: e33835a643a970c11ac74f6333f5f6866387a101
   subpackages:
   - proto
 - name: github.com/golang/glog
@@ -167,17 +167,18 @@ imports:
   subpackages:
   - query
 - name: github.com/gorilla/context
-  version: 08b5f424b9271eedf6f9f0ce86cb9396ed337a42
+  version: aed02d124ae4a0e94fea4541c8effd05bf0c8296
 - name: github.com/hashicorp/consul
-  version: d5b7530ec593f1ec2a8f8a7c145bcadafa88b572
+  version: fce7d75609a04eeb9d4bf41c8dc592aac18fc97d
   subpackages:
   - api
 - name: github.com/hashicorp/go-cleanhttp
-  version: ad28ea4487f05916463e2423a55166280e8254b5
+  version: 875fb671b3ddc66f8e2f0acc33829c8cb989a38d
 - name: github.com/hashicorp/serf
-  version: b7a120a5fc494f6dd5e858f42fd0fd4022d6320f
+  version: 6c4672d66fc6312ddde18399262943e21175d831
   subpackages:
   - coordinate
+  - serf
 - name: github.com/jarcoal/httpmock
   version: 145b10d659265440f062c31ea15326166bae56ee
 - name: github.com/libkermit/compose
@@ -219,7 +220,7 @@ imports:
 - name: github.com/miekg/dns
   version: 5d001d020961ae1c184f9f8152fdc73810481677
 - name: github.com/mitchellh/mapstructure
-  version: ca63d7c062ee3c9f34db231e352b60012b4fd0c1
+  version: d2dd0262208475919e1a362f675cfc0e7c10e905
 - name: github.com/moul/http2curl
   version: b1479103caacaa39319f75e7f57fc545287fca0d
 - name: github.com/NYTimes/gziphandler
@@ -227,11 +228,11 @@ imports:
 - name: github.com/ogier/pflag
   version: 45c278ab3607870051a2ea9040bb85fcb8557481
 - name: github.com/opencontainers/runc
-  version: d9fec4c63b089ddfc267194ecb6cda58a13f072c
+  version: 1a81e9ab1f138c091fe5c86d0883f87716088527
   subpackages:
   - libcontainer/user
 - name: github.com/parnurzeal/gorequest
-  version: 29ced6f360a5ac3823a3675b4e29fbab336cc186
+  version: 045012d33ef41ea146c1b675df9296d0dc1a212d
 - name: github.com/pmezard/go-difflib
   version: d8ed2627bdf02c080bf22230dbb337003b7aba2d
   subpackages:
@@ -239,22 +240,22 @@ imports:
 - name: github.com/ryanuber/go-glob
   version: 572520ed46dbddaed19ea3d9541bdd0494163693
 - name: github.com/samuel/go-zookeeper
-  version: 87e1bca4477a3cc767ca71be023ced183d74e538
+  version: e64db453f3512cade908163702045e0f31137843
   subpackages:
   - zk
 - name: github.com/Sirupsen/logrus
-  version: 3ec0642a7fb6488f65b06f9040adc67e3990296a
+  version: a283a10442df8dc09befd873fab202bf8a253d6a
 - name: github.com/streamrail/concurrent-map
-  version: 8bf1e9bacbf65b10c81d0f4314cf2b1ebef728b5
+  version: 65a174a3a4188c0b7099acbc6cfa0c53628d3287
 - name: github.com/stretchr/objx
   version: cbeaeb16a013161a98496fad62933b1d21786672
 - name: github.com/stretchr/testify
-  version: 976c720a22c8eb4eb6a0b4348ad85ad12491a506
+  version: d77da356e56a7428ad25149ca77381849a6a5232
   subpackages:
   - assert
   - mock
 - name: github.com/thoas/stats
-  version: 152b5d051953fdb6e45f14b6826962aadc032324
+  version: 79b768ff1780f4e5b0ed132e192bfeefe9f85a9c
 - name: github.com/tv42/zbase32
   version: 03389da7e0bf9844767f82690f4d68fc097a1306
 - name: github.com/ugorji/go
@@ -262,7 +263,7 @@ imports:
   subpackages:
   - codec
 - name: github.com/unrolled/render
-  version: 3f4913244021dede105b62caecfb01f0c1eebeda
+  version: 198ad4d8b8a4612176b804ca10555b222a086b40
 - name: github.com/vdemeester/docker-events
   version: be74d4929ec1ad118df54349fda4b0cba60f849b
 - name: github.com/vdemeester/shakers
@@ -284,7 +285,7 @@ imports:
 - name: github.com/vulcand/route
   version: cb89d787ddbb1c5849a7ac9f79004c1fd12a4a32
 - name: github.com/vulcand/vulcand
-  version: 643ca8acff8386e3b276f6feb8ba9b5893dbc4a2
+  version: 28a4e5c0892167589737b95ceecbcef00295be50
   subpackages:
   - conntracker
   - plugin
@@ -314,11 +315,11 @@ imports:
 - name: gopkg.in/fsnotify.v1
   version: a8a77c9133d2d6fd8334f3260d06f60e8d80a5fb
 - name: gopkg.in/mgo.v2
-  version: 22287bab4379e1fbf6002fb4eb769888f3fb224c
+  version: 29cc868a5ca65f401ff318143f9408d02f4799cc
   subpackages:
   - bson
 - name: gopkg.in/square/go-jose.v1
-  version: aa2e30fdd1fe9dd3394119af66451ae790d50e0d
+  version: e3f973b66b91445ec816dd7411ad1b6495a5a2fc
   subpackages:
   - cipher
   - json
@@ -336,9 +337,9 @@ testImports:
 - name: github.com/libkermit/docker-check
   version: cbe0ef03b3d23070eac4d00ba8828f2cc7f7e5a3
 - name: github.com/spf13/pflag
-  version: 08b1a584251b5b62f458943640fc8ebd4d50aaa5
+  version: 5644820622454e71517561946e3d94b9f9db6842
 - name: github.com/vbatts/tar-split
-  version: bd4c5d64c3e9297f410025a3b1bd0c58f659e721
+  version: 6810cedb21b2c3d0b9bb8f9af12ff2dc7a2f14df
   subpackages:
   - archive/tar
   - tar/asm

provider/docker.go

@@ -252,6 +252,7 @@ func (provider *Docker) loadDockerConfig(containersInspected []dockerData) *type
 		"hasMaxConnLabels":            provider.hasMaxConnLabels,
 		"getMaxConnAmount":            provider.getMaxConnAmount,
 		"getMaxConnExtractorFunc":     provider.getMaxConnExtractorFunc,
+		"getSticky":                   provider.getSticky,
 		"replace":                     replace,
 	}
 
@@ -261,18 +262,27 @@ func (provider *Docker) loadDockerConfig(containersInspected []dockerData) *type
 	}, containersInspected).([]dockerData)
 
 	frontends := map[string][]dockerData{}
+	backends := map[string]dockerData{}
+	servers := map[string][]dockerData{}
 	for _, container := range filteredContainers {
 		frontendName := provider.getFrontendName(container)
 		frontends[frontendName] = append(frontends[frontendName], container)
+		backendName := provider.getBackend(container)
+		backends[backendName] = container
+		servers[backendName] = append(servers[backendName], container)
 	}
 
 	templateObjects := struct {
 		Containers []dockerData
 		Frontends  map[string][]dockerData
+		Backends   map[string]dockerData
+		Servers    map[string][]dockerData
 		Domain     string
 	}{
 		filteredContainers,
 		frontends,
+		backends,
+		servers,
 		provider.Domain,
 	}
 
@@ -291,7 +301,9 @@ func (provider *Docker) hasCircuitBreakerLabel(container dockerData) bool {
 }
 
 func (provider *Docker) hasLoadBalancerLabel(container dockerData) bool {
-	if _, err := getLabel(container, "traefik.backend.loadbalancer.method"); err != nil {
+	_, errMethod := getLabel(container, "traefik.backend.loadbalancer.method")
+	_, errSticky := getLabel(container, "traefik.backend.loadbalancer.sticky")
+	if errMethod != nil && errSticky != nil {
 		return false
 	}
 	return true
@@ -439,6 +451,13 @@ func (provider *Docker) getWeight(container dockerData) string {
 	return "1"
 }
 
+func (provider *Docker) getSticky(container dockerData) string {
+	if _, err := getLabel(container, "traefik.backend.loadbalancer.sticky"); err == nil {
+		return "true"
+	}
+	return "false"
+}
+
 func (provider *Docker) getDomain(container dockerData) string {
 	if label, err := getLabel(container, "traefik.domain"); err == nil {
 		return label

provider/docker_test.go

@@ -940,7 +940,6 @@ func TestDockerLoadDockerConfig(t *testing.T) {
 						},
 					},
 					CircuitBreaker: nil,
-					LoadBalancer:   nil,
 				},
 			},
 		},
@@ -1027,7 +1026,6 @@ func TestDockerLoadDockerConfig(t *testing.T) {
 						},
 					},
 					CircuitBreaker: nil,
-					LoadBalancer:   nil,
 				},
 			},
 		},

provider/marathon.go

@@ -138,6 +138,7 @@ func (provider *Marathon) loadMarathonConfig() *types.Configuration {
 		"getMaxConnAmount":            provider.getMaxConnAmount,
 		"getLoadBalancerMethod":       provider.getLoadBalancerMethod,
 		"getCircuitBreakerExpression": provider.getCircuitBreakerExpression,
+		"getSticky":                   provider.getSticky,
 	}
 
 	applications, err := provider.marathonClient.Applications(nil)
@@ -347,6 +348,13 @@ func (provider *Marathon) getProtocol(task marathon.Task, applications []maratho
 	return "http"
 }
 
+func (provider *Marathon) getSticky(application marathon.Application) string {
+	if sticky, err := provider.getLabel(application, "traefik.backend.loadbalancer.sticky"); err == nil {
+		return sticky
+	}
+	return "false"
+}
+
 func (provider *Marathon) getPassHostHeader(application marathon.Application) string {
 	if passHostHeader, err := provider.getLabel(application, "traefik.frontend.passHostHeader"); err == nil {
 		return passHostHeader
@@ -411,7 +419,9 @@ func (provider *Marathon) hasCircuitBreakerLabels(application marathon.Applicati
 }
 
 func (provider *Marathon) hasLoadBalancerLabels(application marathon.Application) bool {
-	if _, err := provider.getLabel(application, "traefik.backend.loadbalancer.method"); err != nil {
+	_, errMethod := provider.getLabel(application, "traefik.backend.loadbalancer.method")
+	_, errSticky := provider.getLabel(application, "traefik.backend.loadbalancer.sticky")
+	if errMethod != nil && errSticky != nil {
 		return false
 	}
 	return true

provider/marathon_test.go

@@ -107,7 +107,6 @@ func TestMarathonLoadConfig(t *testing.T) {
 						},
 					},
 					CircuitBreaker: nil,
-					LoadBalancer:   nil,
 				},
 			},
 		},

server.go

@@ -537,16 +537,30 @@ func (server *Server) loadConfig(configurations configs, globalConfiguration Glo
 							log.Errorf("Skipping frontend %s...", frontendName)
 							continue frontend
 						}
+
 						lbMethod, err := types.NewLoadBalancerMethod(configuration.Backends[frontend.Backend].LoadBalancer)
 						if err != nil {
 							log.Errorf("Error loading load balancer method '%+v' for frontend %s: %v", configuration.Backends[frontend.Backend].LoadBalancer, frontendName, err)
 							log.Errorf("Skipping frontend %s...", frontendName)
 							continue frontend
 						}
+
+						stickysession := configuration.Backends[frontend.Backend].LoadBalancer.Sticky
+						cookiename := "_TRAEFIK_BACKEND"
+						var sticky *roundrobin.StickySession
+
+						if stickysession {
+							sticky = roundrobin.NewStickySession(cookiename)
+						}
+
 						switch lbMethod {
 						case types.Drr:
 							log.Debugf("Creating load-balancer drr")
 							rebalancer, _ := roundrobin.NewRebalancer(rr, roundrobin.RebalancerLogger(oxyLogger))
+							if stickysession {
+								log.Debugf("Sticky session with cookie %v", cookiename)
+								rebalancer, _ = roundrobin.NewRebalancer(rr, roundrobin.RebalancerLogger(oxyLogger), roundrobin.RebalancerStickySession(sticky))
+							}
 							lb = rebalancer
 							for serverName, server := range configuration.Backends[frontend.Backend].Servers {
 								url, err := url.Parse(server.URL)
@@ -565,6 +579,10 @@ func (server *Server) loadConfig(configurations configs, globalConfiguration Glo
 							}
 						case types.Wrr:
 							log.Debugf("Creating load-balancer wrr")
+							if stickysession {
+								log.Debugf("Sticky session with cookie %v", cookiename)
+								rr, _ = roundrobin.New(saveBackend, roundrobin.EnableStickySession(sticky))
+							}
 							lb = rr
 							for serverName, server := range configuration.Backends[frontend.Backend].Servers {
 								url, err := url.Parse(server.URL)

templates/docker.tmpl

@@ -1,23 +1,29 @@
-[backends]{{range .Containers}}
+{{$backendServers := .Servers}}
-    {{if hasCircuitBreakerLabel .}}
+[backends]{{range $backendName, $backend := .Backends}}
-    [backends.backend-{{getBackend .}}.circuitbreaker]
+    {{if hasCircuitBreakerLabel $backend}}
-      expression = "{{getCircuitBreakerExpression .}}"
+    [backends.backend-{{$backendName}}.circuitbreaker]
+      expression = "{{getCircuitBreakerExpression $backend}}"
     {{end}}
 
-    {{if hasLoadBalancerLabel .}}
+    {{if hasLoadBalancerLabel $backend}}
-    [backends.backend-{{getBackend .}}.loadbalancer]
+    [backends.backend-{{$backendName}}.loadbalancer]
-      method = "{{getLoadBalancerMethod .}}"
+      method = "{{getLoadBalancerMethod $backend}}"
+      sticky = {{getSticky $backend}}
     {{end}}
 
-    {{if hasMaxConnLabels .}}
+    {{if hasMaxConnLabels $backend}}
-    [backends.backend-{{getBackend .}}.maxconn]
+    [backends.backend-{{$backendName}}.maxconn]
-      amount = {{getMaxConnAmount . }}
+      amount = {{getMaxConnAmount $backend}}
-      extractorfunc = "{{getMaxConnExtractorFunc . }}"
+      extractorfunc = "{{getMaxConnExtractorFunc $backend}}"
+    {{end}}
+
+    {{$servers := index $backendServers $backendName}}
+    {{range $serverName, $server := $servers}}
+      [backends.backend-{{$backendName}}.servers.server-{{$server.Name | replace "/" "" | replace "." "-"}}]
+      url = "{{getProtocol $server}}://{{getIPAddress $server}}:{{getPort $server}}"
+      weight = {{getWeight $server}}
     {{end}}
 
-    [backends.backend-{{getBackend .}}.servers.server-{{.Name | replace "/" "" | replace "." "-"}}]
-    url = "{{getProtocol .}}://{{getIPAddress .}}:{{getPort .}}"
-    weight = {{getWeight .}}
 {{end}}
 
 [frontends]{{range $frontend, $containers := .Frontends}}

templates/kv.tmpl

@@ -12,9 +12,11 @@
 {{end}}
 
 {{$loadBalancer := Get "" . "/loadbalancer/" "method"}}
+{{$sticky := Get "false" . "/loadbalancer/" "sticky"}}
 {{with $loadBalancer}}
 [backends."{{Last $backend}}".loadBalancer]
     method = "{{$loadBalancer}}"
+    sticky = {{$sticky}}
 {{end}}
 
 {{$maxConnAmt := Get "" . "/maxconn/" "amount"}}

templates/marathon.tmpl

@@ -14,6 +14,7 @@
 {{ if hasLoadBalancerLabels . }}
       [backends.backend{{getFrontendBackend . }}.loadbalancer]
         method = "{{getLoadBalancerMethod . }}"
+        sticky = {{getSticky .}}
 {{end}}
 {{ if hasCircuitBreakerLabels . }}
       [backends.backend{{getFrontendBackend . }}.circuitbreaker]

types/types.go

@@ -24,6 +24,7 @@ type MaxConn struct {
 // LoadBalancer holds load balancing configuration.
 type LoadBalancer struct {
 	Method string `json:"method,omitempty"`
+	Sticky bool   `json:"sticky,omitempty"`
 }
 
 // CircuitBreaker holds circuit breaker configuration.