Adds weight on ServersLoadBalancer

docs/content/reference/dynamic-configuration/docker-labels.yml

@@ -178,6 +178,7 @@
 - "traefik.http.services.service02.loadbalancer.sticky.cookie.secure=true"
 - "traefik.http.services.service02.loadbalancer.server.port=foobar"
 - "traefik.http.services.service02.loadbalancer.server.scheme=foobar"
+- "traefik.http.services.service02.loadbalancer.server.weight=42"
 - "traefik.tcp.middlewares.tcpmiddleware01.ipallowlist.sourcerange=foobar, foobar"
 - "traefik.tcp.middlewares.tcpmiddleware02.ipwhitelist.sourcerange=foobar, foobar"
 - "traefik.tcp.middlewares.tcpmiddleware03.inflightconn.amount=42"

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

@@ -58,9 +58,11 @@
 
         [[http.services.Service02.loadBalancer.servers]]
           url = "foobar"
+          weight = 42
 
         [[http.services.Service02.loadBalancer.servers]]
           url = "foobar"
+          weight = 42
         [http.services.Service02.loadBalancer.healthCheck]
           scheme = "foobar"
           mode = "foobar"

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

@@ -65,7 +65,9 @@ http:
             maxAge: 42
         servers:
           - url: foobar
+            weight: 42
           - url: foobar
+            weight: 42
         healthCheck:
           scheme: foobar
           mode: foobar

docs/content/reference/dynamic-configuration/kv-ref.md

@@ -240,7 +240,9 @@ THIS FILE MUST NOT BE EDITED BY HAND
 | `traefik/http/services/Service02/loadBalancer/passHostHeader` | `true` |
 | `traefik/http/services/Service02/loadBalancer/responseForwarding/flushInterval` | `42s` |
 | `traefik/http/services/Service02/loadBalancer/servers/0/url` | `foobar` |
+| `traefik/http/services/Service02/loadBalancer/servers/0/weight` | `42` |
 | `traefik/http/services/Service02/loadBalancer/servers/1/url` | `foobar` |
+| `traefik/http/services/Service02/loadBalancer/servers/1/weight` | `42` |
 | `traefik/http/services/Service02/loadBalancer/serversTransport` | `foobar` |
 | `traefik/http/services/Service02/loadBalancer/sticky/cookie/httpOnly` | `true` |
 | `traefik/http/services/Service02/loadBalancer/sticky/cookie/maxAge` | `42` |

docs/content/routing/services/index.md

@@ -143,6 +143,36 @@ The `url` option point to a specific instance.
           url = "http://private-ip-server-1/"
     ```
 
+The `weight` option allows for weighted load balancing on the servers.
+
+??? example "A Service with Two Servers with Weight -- Using the [File Provider](../../providers/file.md)"
+
+    ```yaml tab="YAML"
+    ## Dynamic configuration
+    http:
+      services:
+        my-service:
+          loadBalancer:
+            servers:
+              - url: "http://private-ip-server-1/"
+                weight: 2
+              - url: "http://private-ip-server-2/"
+                weight: 1
+
+    ```
+
+    ```toml tab="TOML"
+    ## Dynamic configuration
+    [http.services]
+      [http.services.my-service.loadBalancer]
+        [[http.services.my-service.loadBalancer.servers]]
+          url = "http://private-ip-server-1/"
+          weight = 2
+        [[http.services.my-service.loadBalancer.servers]]
+          url = "http://private-ip-server-2/"
+          weight = 1
+    ```
+
 #### Load-balancing
 
 For now, only round robin load balancing is supported:

integration/docker_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"io"
 	"net/http"
+	"strings"
 	"testing"
 	"time"
 
@@ -55,6 +56,56 @@ func (s *DockerSuite) TestSimpleConfiguration() {
 	require.NoError(s.T(), err)
 }
 
+func (s *DockerSuite) TestWRRServer() {
+	tempObjects := struct {
+		DockerHost  string
+		DefaultRule string
+	}{
+		DockerHost:  s.getDockerHost(),
+		DefaultRule: "Host(`{{ normalize .Name }}.docker.localhost`)",
+	}
+
+	file := s.adaptFile("fixtures/docker/simple.toml", tempObjects)
+
+	s.composeUp()
+
+	s.traefikCmd(withConfigFile(file))
+
+	whoami1IP := s.getComposeServiceIP("wrr-server")
+	whoami2IP := s.getComposeServiceIP("wrr-server2")
+
+	// Expected a 404 as we did not configure anything
+	err := try.GetRequest("http://127.0.0.1:8000/", 500*time.Millisecond, try.StatusCodeIs(http.StatusNotFound))
+	require.NoError(s.T(), err)
+
+	err = try.GetRequest("http://127.0.0.1:8080/api/http/services", 1000*time.Millisecond, try.BodyContains("wrr-server"))
+	require.NoError(s.T(), err)
+
+	repartition := map[string]int{}
+	for i := 0; i < 4; i++ {
+		req, err := http.NewRequest(http.MethodGet, "http://127.0.0.1:8000/whoami", nil)
+		req.Host = "my.wrr.host"
+		require.NoError(s.T(), err)
+
+		response, err := http.DefaultClient.Do(req)
+		require.NoError(s.T(), err)
+		assert.Equal(s.T(), http.StatusOK, response.StatusCode)
+
+		body, err := io.ReadAll(response.Body)
+		require.NoError(s.T(), err)
+
+		if strings.Contains(string(body), whoami1IP) {
+			repartition[whoami1IP]++
+		}
+		if strings.Contains(string(body), whoami2IP) {
+			repartition[whoami2IP]++
+		}
+	}
+
+	assert.Equal(s.T(), 3, repartition[whoami1IP])
+	assert.Equal(s.T(), 1, repartition[whoami2IP])
+}
+
 func (s *DockerSuite) TestDefaultDockerContainers() {
 	tempObjects := struct {
 		DockerHost  string

integration/fixtures/wrr_server.toml

@@ -0,0 +1,35 @@
+[global]
+  checkNewVersion = false
+  sendAnonymousUsage = false
+
+[api]
+  insecure = true
+
+[log]
+  level = "DEBUG"
+  noColor = true
+
+[entryPoints]
+
+  [entryPoints.web]
+    address = ":8000"
+
+[providers.file]
+  filename = "{{ .SelfFilename }}"
+
+## dynamic configuration ##
+
+[http.routers]
+  [http.routers.router]
+    service = "service1"
+    rule = "Path(`/whoami`)"
+
+[http.services]
+
+  [http.services.service1.loadBalancer]
+    [[http.services.service1.loadBalancer.servers]]
+      url = "{{ .Server1 }}"
+      weight = 3
+    [[http.services.service1.loadBalancer.servers]]
+      url = "{{ .Server2 }}"
+

integration/resources/compose/docker.yml

@@ -36,3 +36,14 @@ services:
     labels:
       traefik.http.Routers.Super.Rule: Host(`my.super.host`)
       traefik.http.Services.powpow.LoadBalancer.server.Port: 2375
+
+  wrr-server:
+    image: traefik/whoami
+    labels:
+      traefik.http.Routers.wrr-server.Rule: Host(`my.wrr.host`)
+      traefik.http.Services.wrr-server.LoadBalancer.server.Weight: 4
+  wrr-server2:
+    image: traefik/whoami
+    labels:
+      traefik.http.Routers.wrr-server.Rule: Host(`my.wrr.host`)
+      traefik.http.Services.wrr-server.LoadBalancer.server.Weight: 1

integration/simple_test.go

@@ -809,6 +809,49 @@ func (s *SimpleSuite) TestUDPServiceConfigErrors() {
 	require.NoError(s.T(), err)
 }
 
+func (s *SimpleSuite) TestWRRServer() {
+	s.createComposeProject("base")
+
+	s.composeUp()
+	defer s.composeDown()
+
+	whoami1IP := s.getComposeServiceIP("whoami1")
+	whoami2IP := s.getComposeServiceIP("whoami2")
+
+	file := s.adaptFile("fixtures/wrr_server.toml", struct {
+		Server1 string
+		Server2 string
+	}{Server1: "http://" + whoami1IP, Server2: "http://" + whoami2IP})
+
+	s.traefikCmd(withConfigFile(file))
+
+	err := try.GetRequest("http://127.0.0.1:8080/api/http/services", 1000*time.Millisecond, try.BodyContains("service1"))
+	require.NoError(s.T(), err)
+
+	repartition := map[string]int{}
+	for i := 0; i < 4; i++ {
+		req, err := http.NewRequest(http.MethodGet, "http://127.0.0.1:8000/whoami", nil)
+		require.NoError(s.T(), err)
+
+		response, err := http.DefaultClient.Do(req)
+		require.NoError(s.T(), err)
+		assert.Equal(s.T(), http.StatusOK, response.StatusCode)
+
+		body, err := io.ReadAll(response.Body)
+		require.NoError(s.T(), err)
+
+		if strings.Contains(string(body), whoami1IP) {
+			repartition[whoami1IP]++
+		}
+		if strings.Contains(string(body), whoami2IP) {
+			repartition[whoami2IP]++
+		}
+	}
+
+	assert.Equal(s.T(), 3, repartition[whoami1IP])
+	assert.Equal(s.T(), 1, repartition[whoami2IP])
+}
+
 func (s *SimpleSuite) TestWRR() {
 	s.createComposeProject("base")
 

pkg/config/dynamic/http_config.go

@@ -227,6 +227,7 @@ func (r *ResponseForwarding) SetDefaults() {
 // Server holds the server configuration.
 type Server struct {
 	URL    string `json:"url,omitempty" toml:"url,omitempty" yaml:"url,omitempty" label:"-"`
+	Weight *int   `json:"weight,omitempty" toml:"weight,omitempty" yaml:"weight,omitempty" label:"weight"`
 	Scheme string `json:"-" toml:"-" yaml:"-" file:"-"`
 	Port   string `json:"-" toml:"-" yaml:"-" file:"-"`
 }

pkg/config/dynamic/zz_generated.deepcopy.go

@@ -1128,6 +1128,11 @@ func (in *RouterTLSConfig) DeepCopy() *RouterTLSConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Server) DeepCopyInto(out *Server) {
 	*out = *in
+	if in.Weight != nil {
+		in, out := &in.Weight, &out.Weight
+		*out = new(int)
+		**out = **in
+	}
 	return
 }
 
@@ -1180,7 +1185,9 @@ func (in *ServersLoadBalancer) DeepCopyInto(out *ServersLoadBalancer) {
 	if in.Servers != nil {
 		in, out := &in.Servers, &out.Servers
 		*out = make([]Server, len(*in))
-		copy(*out, *in)
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
 	}
 	if in.HealthCheck != nil {
 		in, out := &in.HealthCheck, &out.HealthCheck

pkg/server/service/service.go

@@ -319,7 +319,7 @@ func (m *Manager) getLoadBalancerServiceHandler(ctx context.Context, serviceName
 
 		proxy = tracingMiddle.NewService(ctx, serviceName, proxy)
 
-		lb.Add(proxyName, proxy, nil)
+		lb.Add(proxyName, proxy, server.Weight)
 
 		// servers are considered UP by default.
 		info.UpdateServerStatus(target.String(), runtime.StatusUp)