Enables the use of elements declared in other providers

integration/fixtures/multiprovider.toml

@@ -0,0 +1,24 @@
+[log]
+logLevel = "DEBUG"
+
+[api]
+
+[entryPoints]
+  [entryPoints.http]
+  address = ":8000"
+
+[Providers]
+   [Providers.Rest]
+
+   [Providers.File]
+
+[Services]
+  [Services.service]
+    [Services.service.LoadBalancer]
+
+      [[Services.service.LoadBalancer.Servers]]
+        URL = "{{.Server}}"
+        Weight = 1
+[Middlewares]
+  [Middlewares.customheader.Headers.CustomRequestHeaders]
+  X-Custom="CustomValue"

integration/simple_test.go

@@ -1,6 +1,8 @@
 package integration
 
 import (
+	"bytes"
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
@@ -9,6 +11,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/containous/traefik/config"
 	"github.com/containous/traefik/integration/try"
 	"github.com/go-check/check"
 	checker "github.com/vdemeester/shakers"
@@ -434,3 +437,53 @@ func (s *SimpleSuite) TestKeepTrailingSlash(c *check.C) {
 
 	http.DefaultClient.CheckRedirect = oldCheckRedirect
 }
+
+func (s *SimpleSuite) TestMultiprovider(c *check.C) {
+	s.createComposeProject(c, "base")
+	s.composeProject.Start(c)
+
+	server := "http://" + s.composeProject.Container(c, "whoami1").NetworkSettings.IPAddress
+
+	file := s.adaptFile(c, "fixtures/multiprovider.toml", struct {
+		Server string
+	}{Server: server})
+	defer os.Remove(file)
+
+	cmd, output := s.traefikCmd(withConfigFile(file))
+	defer output(c)
+
+	err := cmd.Start()
+	c.Assert(err, checker.IsNil)
+	defer cmd.Process.Kill()
+
+	err = try.GetRequest("http://127.0.0.1:8080/api/providers/file/services", 1000*time.Millisecond, try.BodyContains("service"))
+	c.Assert(err, checker.IsNil)
+
+	config := config.Configuration{
+		Routers: map[string]*config.Router{
+			"router1": {
+				EntryPoints: []string{"http"},
+				Middlewares: []string{"file.customheader"},
+				Service:     "file.service",
+				Rule:        "PathPrefix:/",
+			},
+		},
+	}
+
+	json, err := json.Marshal(config)
+	c.Assert(err, checker.IsNil)
+
+	request, err := http.NewRequest(http.MethodPut, "http://127.0.0.1:8080/api/providers/rest", bytes.NewReader(json))
+	c.Assert(err, checker.IsNil)
+
+	response, err := http.DefaultClient.Do(request)
+	c.Assert(err, checker.IsNil)
+	c.Assert(response.StatusCode, checker.Equals, http.StatusOK)
+
+	err = try.GetRequest("http://127.0.0.1:8080/api/providers/rest/routers", 1000*time.Millisecond, try.BodyContains("PathPrefix:/"))
+	c.Assert(err, checker.IsNil)
+
+	err = try.GetRequest("http://127.0.0.1:8000/", 1*time.Second, try.StatusCodeIs(http.StatusOK), try.BodyContains("CustomValue"))
+	c.Assert(err, checker.IsNil)
+
+}

integration/tracing_test.go

@@ -85,7 +85,7 @@ func (s *TracingSuite) TestZipkinRateLimit(c *check.C) {
 	err = try.GetRequest("http://127.0.0.1:8000/ratelimit", 500*time.Millisecond, try.StatusCodeIs(http.StatusTooManyRequests))
 	c.Assert(err, checker.IsNil)
 
-	err = try.GetRequest("http://"+s.ZipkinIP+":9411/api/v2/spans?serviceName=tracing", 20*time.Second, try.BodyContains("forward service1/router1", "ratelimit"))
+	err = try.GetRequest("http://"+s.ZipkinIP+":9411/api/v2/spans?serviceName=tracing", 20*time.Second, try.BodyContains("forward service1/file.router1", "file.ratelimit"))
 	c.Assert(err, checker.IsNil)
 
 }
@@ -109,7 +109,7 @@ func (s *TracingSuite) TestZipkinRetry(c *check.C) {
 	err = try.GetRequest("http://127.0.0.1:8000/retry", 500*time.Millisecond, try.StatusCodeIs(http.StatusBadGateway))
 	c.Assert(err, checker.IsNil)
 
-	err = try.GetRequest("http://"+s.ZipkinIP+":9411/api/v2/spans?serviceName=tracing", 20*time.Second, try.BodyContains("forward service2/router2", "retry"))
+	err = try.GetRequest("http://"+s.ZipkinIP+":9411/api/v2/spans?serviceName=tracing", 20*time.Second, try.BodyContains("forward service2/file.router2", "file.retry"))
 	c.Assert(err, checker.IsNil)
 }
 
@@ -132,6 +132,6 @@ func (s *TracingSuite) TestZipkinAuth(c *check.C) {
 	err = try.GetRequest("http://127.0.0.1:8000/auth", 500*time.Millisecond, try.StatusCodeIs(http.StatusUnauthorized))
 	c.Assert(err, checker.IsNil)
 
-	err = try.GetRequest("http://"+s.ZipkinIP+":9411/api/v2/spans?serviceName=tracing", 20*time.Second, try.BodyContains("entrypoint http", "basic-auth"))
+	err = try.GetRequest("http://"+s.ZipkinIP+":9411/api/v2/spans?serviceName=tracing", 20*time.Second, try.BodyContains("entrypoint http", "file.basic-auth"))
 	c.Assert(err, checker.IsNil)
 }

middlewares/chain/chain.go

@@ -14,17 +14,13 @@ const (
 )
 
 type chainBuilder interface {
-	BuildChain(ctx context.Context, middlewares []string) (*alice.Chain, error)
+	BuildChain(ctx context.Context, middlewares []string) *alice.Chain
 }
 
 // New creates a chain middleware
 func New(ctx context.Context, next http.Handler, config config.Chain, builder chainBuilder, name string) (http.Handler, error) {
 	middlewares.GetLogger(ctx, name, typeName).Debug("Creating middleware")
 
-	middlewareChain, err := builder.BuildChain(ctx, config.Middlewares)
-	if err != nil {
-		return nil, err
-	}
-
+	middlewareChain := builder.BuildChain(ctx, config.Middlewares)
 	return middlewareChain.Then(next)
 }

server/aggregator.go

@@ -0,0 +1,29 @@
+package server
+
+import (
+	"github.com/containous/traefik/config"
+	"github.com/containous/traefik/server/internal"
+)
+
+func mergeConfiguration(configurations config.Configurations) config.Configuration {
+	conf := config.Configuration{
+		Routers:     make(map[string]*config.Router),
+		Middlewares: make(map[string]*config.Middleware),
+		Services:    make(map[string]*config.Service),
+	}
+
+	for provider, configuration := range configurations {
+		for routerName, router := range configuration.Routers {
+			conf.Routers[internal.MakeQualifiedName(provider, routerName)] = router
+		}
+		for middlewareName, middleware := range configuration.Middlewares {
+			conf.Middlewares[internal.MakeQualifiedName(provider, middlewareName)] = middleware
+		}
+		for serviceName, service := range configuration.Services {
+			conf.Services[internal.MakeQualifiedName(provider, serviceName)] = service
+		}
+		conf.TLS = append(conf.TLS, configuration.TLS...)
+	}
+
+	return conf
+}

server/aggregator_test.go

@@ -0,0 +1,103 @@
+package server
+
+import (
+	"testing"
+
+	"github.com/containous/traefik/config"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAggregator(t *testing.T) {
+	testCases := []struct {
+		desc     string
+		given    config.Configurations
+		expected config.Configuration
+	}{
+		{
+			desc:  "Nil returns an empty configuration",
+			given: nil,
+			expected: config.Configuration{
+				Routers:     make(map[string]*config.Router),
+				Middlewares: make(map[string]*config.Middleware),
+				Services:    make(map[string]*config.Service),
+			},
+		},
+		{
+			desc: "Returns fully qualified elements from a mono-provider configuration map",
+			given: config.Configurations{
+				"provider-1": &config.Configuration{
+					Routers: map[string]*config.Router{
+						"router-1": {},
+					},
+					Middlewares: map[string]*config.Middleware{
+						"middleware-1": {},
+					},
+					Services: map[string]*config.Service{
+						"service-1": {},
+					},
+				},
+			},
+			expected: config.Configuration{
+				Routers: map[string]*config.Router{
+					"provider-1.router-1": {},
+				},
+				Middlewares: map[string]*config.Middleware{
+					"provider-1.middleware-1": {},
+				},
+				Services: map[string]*config.Service{
+					"provider-1.service-1": {},
+				},
+			},
+		},
+		{
+			desc: "Returns fully qualified elements from a multi-provider configuration map",
+			given: config.Configurations{
+				"provider-1": &config.Configuration{
+					Routers: map[string]*config.Router{
+						"router-1": {},
+					},
+					Middlewares: map[string]*config.Middleware{
+						"middleware-1": {},
+					},
+					Services: map[string]*config.Service{
+						"service-1": {},
+					},
+				},
+				"provider-2": &config.Configuration{
+					Routers: map[string]*config.Router{
+						"router-1": {},
+					},
+					Middlewares: map[string]*config.Middleware{
+						"middleware-1": {},
+					},
+					Services: map[string]*config.Service{
+						"service-1": {},
+					},
+				},
+			},
+			expected: config.Configuration{
+				Routers: map[string]*config.Router{
+					"provider-1.router-1": {},
+					"provider-2.router-1": {},
+				},
+				Middlewares: map[string]*config.Middleware{
+					"provider-1.middleware-1": {},
+					"provider-2.middleware-1": {},
+				},
+				Services: map[string]*config.Service{
+					"provider-1.service-1": {},
+					"provider-2.service-1": {},
+				},
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+			actual := mergeConfiguration(test.given)
+			assert.Equal(t, test.expected, actual)
+		})
+	}
+}

server/internal/provider.go

@@ -0,0 +1,45 @@
+package internal
+
+import (
+	"context"
+	"strings"
+
+	"github.com/containous/traefik/log"
+)
+
+type contextKey int
+
+const (
+	providerKey contextKey = iota
+)
+
+// AddProviderInContext Adds the provider name in the context
+func AddProviderInContext(ctx context.Context, elementName string) context.Context {
+	parts := strings.Split(elementName, ".")
+	if len(parts) == 1 {
+		log.FromContext(ctx).Debugf("Could not find a provider for %s.", elementName)
+		return ctx
+	}
+
+	if name, ok := ctx.Value(providerKey).(string); ok && name == parts[0] {
+		return ctx
+	}
+
+	return context.WithValue(ctx, providerKey, parts[0])
+}
+
+// GetQualifiedName Gets the fully qualified name.
+func GetQualifiedName(ctx context.Context, elementName string) string {
+	parts := strings.Split(elementName, ".")
+	if len(parts) == 1 {
+		if providerName, ok := ctx.Value(providerKey).(string); ok {
+			return MakeQualifiedName(providerName, parts[0])
+		}
+	}
+	return elementName
+}
+
+// MakeQualifiedName Creates a qualified name for an element
+func MakeQualifiedName(providerName string, elementName string) string {
+	return providerName + "." + elementName
+}

server/middleware/middlewares.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/containous/alice"
 	"github.com/containous/traefik/config"
@@ -26,9 +27,16 @@ import (
 	"github.com/containous/traefik/middlewares/stripprefix"
 	"github.com/containous/traefik/middlewares/stripprefixregex"
 	"github.com/containous/traefik/middlewares/tracing"
+	"github.com/containous/traefik/server/internal"
 	"github.com/pkg/errors"
 )
 
+type middlewareStackType int
+
+const (
+	middlewareStackKey middlewareStackType = iota
+)
+
 // Builder the middleware builder
 type Builder struct {
 	configs        map[string]*config.Middleware
@@ -45,22 +53,40 @@ func NewBuilder(configs map[string]*config.Middleware, serviceBuilder serviceBui
 }
 
 // BuildChain creates a middleware chain
-func (b *Builder) BuildChain(ctx context.Context, middlewares []string) (*alice.Chain, error) {
+func (b *Builder) BuildChain(ctx context.Context, middlewares []string) *alice.Chain {
 	chain := alice.New()
 	for _, middlewareName := range middlewares {
+		middlewareName := internal.GetQualifiedName(ctx, middlewareName)
+		constructorContext := internal.AddProviderInContext(ctx, middlewareName)
+		chain = chain.Append(func(next http.Handler) (http.Handler, error) {
+			var err error
+			if constructorContext, err = checkRecursivity(constructorContext, middlewareName); err != nil {
+				return nil, err
+			}
+
 			if _, ok := b.configs[middlewareName]; !ok {
 				return nil, fmt.Errorf("middleware %q does not exist", middlewareName)
 			}
 
-		constructor, err := b.buildConstructor(ctx, middlewareName, *b.configs[middlewareName])
+			constructor, err := b.buildConstructor(constructorContext, middlewareName, *b.configs[middlewareName])
 			if err != nil {
-			return nil, err
+				return nil, fmt.Errorf("error while instanciation of %s: %v", middlewareName, err)
 			}
-		if constructor != nil {
-			chain = chain.Append(constructor)
+			return constructor(next)
+		})
 	}
+	return &chain
+}
+
+func checkRecursivity(ctx context.Context, middlewareName string) (context.Context, error) {
+	currentStack, ok := ctx.Value(middlewareStackKey).([]string)
+	if !ok {
+		currentStack = []string{}
 	}
-	return &chain, nil
+	if inSlice(middlewareName, currentStack) {
+		return ctx, fmt.Errorf("could not instantiate middleware %s: recursion detected in %s", middlewareName, strings.Join(append(currentStack, middlewareName), "->"))
+	}
+	return context.WithValue(ctx, middlewareStackKey, append(currentStack, middlewareName)), nil
 }
 
 func (b *Builder) buildConstructor(ctx context.Context, middlewareName string, config config.Middleware) (alice.Constructor, error) {
@@ -290,3 +316,12 @@ func (b *Builder) buildConstructor(ctx context.Context, middlewareName string, c
 
 	return tracing.Wrap(ctx, middleware), nil
 }
+
+func inSlice(element string, stack []string) bool {
+	for _, value := range stack {
+		if value == element {
+			return true
+		}
+	}
+	return false
+}

server/middleware/middlewares_test.go

@@ -3,9 +3,13 @@ package middleware
 import (
 	"context"
 	"net/http"
+	"net/http/httptest"
 	"testing"
 
 	"github.com/containous/traefik/config"
+	"github.com/containous/traefik/server/internal"
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -67,10 +71,8 @@ func TestMiddlewaresRegistry_BuildChainNilConfig(t *testing.T) {
 	}
 	middlewaresBuilder := NewBuilder(testConfig, nil)
 
-	chain, err := middlewaresBuilder.BuildChain(context.Background(), []string{"empty"})
-	require.NoError(t, err)
-
-	_, err = chain.Then(nil)
+	chain := middlewaresBuilder.BuildChain(context.Background(), []string{"empty"})
+	_, err := chain.Then(nil)
 	require.NoError(t, err)
 }
 
@@ -125,3 +127,254 @@ func TestMiddlewaresRegistry_BuildMiddlewareAddPrefix(t *testing.T) {
 		})
 	}
 }
+
+func TestChainWithContext(t *testing.T) {
+	testCases := []struct {
+		desc            string
+		buildChain      []string
+		configuration   map[string]*config.Middleware
+		expected        map[string]string
+		contextProvider string
+		expectedError   error
+	}{
+		{
+			desc:       "Simple middleware",
+			buildChain: []string{"middleware-1"},
+			configuration: map[string]*config.Middleware{
+				"middleware-1": {
+					Headers: &config.Headers{
+						CustomRequestHeaders: map[string]string{"middleware-1": "value-middleware-1"},
+					},
+				},
+			},
+			expected: map[string]string{"middleware-1": "value-middleware-1"},
+		},
+		{
+			desc:       "Middleware that references a chain",
+			buildChain: []string{"middleware-chain-1"},
+			configuration: map[string]*config.Middleware{
+				"middleware-1": {
+					Headers: &config.Headers{
+						CustomRequestHeaders: map[string]string{"middleware-1": "value-middleware-1"},
+					},
+				},
+				"middleware-chain-1": {
+					Chain: &config.Chain{
+						Middlewares: []string{"middleware-1"},
+					},
+				},
+			},
+			expected: map[string]string{"middleware-1": "value-middleware-1"},
+		},
+		{
+			desc:       "Should prefix the middlewareName with the provider in the context",
+			buildChain: []string{"middleware-1"},
+			configuration: map[string]*config.Middleware{
+				"provider-1.middleware-1": {
+					Headers: &config.Headers{
+						CustomRequestHeaders: map[string]string{"provider-1.middleware-1": "value-middleware-1"},
+					},
+				},
+			},
+			expected:        map[string]string{"provider-1.middleware-1": "value-middleware-1"},
+			contextProvider: "provider-1",
+		},
+		{
+			desc:       "Should not prefix a qualified middlewareName with the provider in the context",
+			buildChain: []string{"provider-1.middleware-1"},
+			configuration: map[string]*config.Middleware{
+				"provider-1.middleware-1": {
+					Headers: &config.Headers{
+						CustomRequestHeaders: map[string]string{"provider-1.middleware-1": "value-middleware-1"},
+					},
+				},
+			},
+			expected:        map[string]string{"provider-1.middleware-1": "value-middleware-1"},
+			contextProvider: "provider-1",
+		},
+		{
+			desc:       "Should be context aware if a chain references another middleware",
+			buildChain: []string{"provider-1.middleware-chain-1"},
+			configuration: map[string]*config.Middleware{
+				"provider-1.middleware-1": {
+					Headers: &config.Headers{
+						CustomRequestHeaders: map[string]string{"middleware-1": "value-middleware-1"},
+					},
+				},
+				"provider-1.middleware-chain-1": {
+					Chain: &config.Chain{
+						Middlewares: []string{"middleware-1"},
+					},
+				},
+			},
+			expected: map[string]string{"middleware-1": "value-middleware-1"},
+		},
+		{
+			desc:       "Should handle nested chains with different context",
+			buildChain: []string{"provider-1.middleware-chain-1", "middleware-chain-1"},
+			configuration: map[string]*config.Middleware{
+				"provider-1.middleware-1": {
+					Headers: &config.Headers{
+						CustomRequestHeaders: map[string]string{"middleware-1": "value-middleware-1"},
+					},
+				},
+				"provider-1.middleware-2": {
+					Headers: &config.Headers{
+						CustomRequestHeaders: map[string]string{"middleware-2": "value-middleware-2"},
+					},
+				},
+				"provider-1.middleware-chain-1": {
+					Chain: &config.Chain{
+						Middlewares: []string{"middleware-1"},
+					},
+				},
+				"provider-1.middleware-chain-2": {
+					Chain: &config.Chain{
+						Middlewares: []string{"middleware-2"},
+					},
+				},
+				"provider-2.middleware-chain-1": {
+					Chain: &config.Chain{
+						Middlewares: []string{"provider-1.middleware-2", "provider-1.middleware-chain-2"},
+					},
+				},
+			},
+			expected:        map[string]string{"middleware-1": "value-middleware-1", "middleware-2": "value-middleware-2"},
+			contextProvider: "provider-2",
+		},
+		{
+			desc:       "Detects recursion in Middleware chain",
+			buildChain: []string{"m1"},
+			configuration: map[string]*config.Middleware{
+				"ok": {
+					Retry: &config.Retry{},
+				},
+				"m1": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m2"},
+					},
+				},
+				"m2": {
+					Chain: &config.Chain{
+						Middlewares: []string{"ok", "m3"},
+					},
+				},
+				"m3": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m1"},
+					},
+				},
+			},
+			expectedError: errors.New("could not instantiate middleware m1: recursion detected in m1->m2->m3->m1"),
+		},
+		{
+			desc:       "Detects recursion in Middleware chain",
+			buildChain: []string{"provider.m1"},
+			configuration: map[string]*config.Middleware{
+				"provider2.ok": {
+					Retry: &config.Retry{},
+				},
+				"provider.m1": {
+					Chain: &config.Chain{
+						Middlewares: []string{"provider2.m2"},
+					},
+				},
+				"provider2.m2": {
+					Chain: &config.Chain{
+						Middlewares: []string{"ok", "provider.m3"},
+					},
+				},
+				"provider.m3": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m1"},
+					},
+				},
+			},
+			expectedError: errors.New("could not instantiate middleware provider.m1: recursion detected in provider.m1->provider2.m2->provider.m3->provider.m1"),
+		},
+		{
+			buildChain: []string{"ok", "m0"},
+			configuration: map[string]*config.Middleware{
+				"ok": {
+					Retry: &config.Retry{},
+				},
+				"m0": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m0"},
+					},
+				},
+			},
+			expectedError: errors.New("could not instantiate middleware m0: recursion detected in m0->m0"),
+		},
+		{
+			desc:       "Detects MiddlewareChain that references a Chain that references a Chain with a missing middleware",
+			buildChain: []string{"m0"},
+			configuration: map[string]*config.Middleware{
+				"m0": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m1"},
+					},
+				},
+				"m1": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m2"},
+					},
+				},
+				"m2": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m3"},
+					},
+				},
+				"m3": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m2"},
+					},
+				},
+			},
+			expectedError: errors.New("could not instantiate middleware m2: recursion detected in m0->m1->m2->m3->m2"),
+		},
+		{
+			desc:       "--",
+			buildChain: []string{"m0"},
+			configuration: map[string]*config.Middleware{
+				"m0": {
+					Chain: &config.Chain{
+						Middlewares: []string{"m0"},
+					},
+				},
+			},
+			expectedError: errors.New("could not instantiate middleware m0: recursion detected in m0->m0"),
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			ctx := context.Background()
+			if len(test.contextProvider) > 0 {
+				ctx = internal.AddProviderInContext(ctx, test.contextProvider+".foobar")
+			}
+
+			builder := NewBuilder(test.configuration, nil)
+
+			result := builder.BuildChain(ctx, test.buildChain)
+
+			handlers, err := result.Then(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(http.StatusOK) }))
+			if test.expectedError != nil {
+				require.NotNil(t, err)
+				require.Equal(t, test.expectedError.Error(), err.Error())
+			} else {
+				require.NoError(t, err)
+				recorder := httptest.NewRecorder()
+				request, _ := http.NewRequest(http.MethodGet, "http://foo/", nil)
+				handlers.ServeHTTP(recorder, request)
+
+				for key, value := range test.expected {
+					assert.Equal(t, value, request.Header.Get(key))
+				}
+			}
+		})
+	}
+}

server/router/route_appender_aggregator.go

@@ -15,13 +15,11 @@ import (
 
 // chainBuilder The contract of the middleware builder
 type chainBuilder interface {
-	BuildChain(ctx context.Context, middlewares []string) (*alice.Chain, error)
+	BuildChain(ctx context.Context, middlewares []string) *alice.Chain
 }
 
 // NewRouteAppenderAggregator Creates a new RouteAppenderAggregator
 func NewRouteAppenderAggregator(ctx context.Context, chainBuilder chainBuilder, conf static.Configuration, entryPointName string, currentConfiguration *safe.Safe) *RouteAppenderAggregator {
-	logger := log.FromContext(ctx)
-
 	aggregator := &RouteAppenderAggregator{}
 
 	if conf.Providers != nil && conf.Providers.Rest != nil {
@@ -29,10 +27,7 @@ func NewRouteAppenderAggregator(ctx context.Context, chainBuilder chainBuilder,
 	}
 
 	if conf.API != nil && conf.API.EntryPoint == entryPointName {
-		chain, err := chainBuilder.BuildChain(ctx, conf.API.Middlewares)
-		if err != nil {
-			logger.Error(err)
-		} else {
+		chain := chainBuilder.BuildChain(ctx, conf.API.Middlewares)
 		aggregator.AddAppender(&WithMiddleware{
 			appender: api.Handler{
 				EntryPoint:            conf.API.EntryPoint,
@@ -44,32 +39,24 @@ func NewRouteAppenderAggregator(ctx context.Context, chainBuilder chainBuilder,
 			},
 			routerMiddlewares: chain,
 		})
-		}
+
 	}
 
 	if conf.Ping != nil && conf.Ping.EntryPoint == entryPointName {
-		chain, err := chainBuilder.BuildChain(ctx, conf.Ping.Middlewares)
-		if err != nil {
-			logger.Error(err)
-		} else {
+		chain := chainBuilder.BuildChain(ctx, conf.Ping.Middlewares)
 		aggregator.AddAppender(&WithMiddleware{
 			appender:          conf.Ping,
 			routerMiddlewares: chain,
 		})
 	}
-	}
 
 	if conf.Metrics != nil && conf.Metrics.Prometheus != nil && conf.Metrics.Prometheus.EntryPoint == entryPointName {
-		chain, err := chainBuilder.BuildChain(ctx, conf.Metrics.Prometheus.Middlewares)
-		if err != nil {
-			logger.Error(err)
-		} else {
+		chain := chainBuilder.BuildChain(ctx, conf.Metrics.Prometheus.Middlewares)
 		aggregator.AddAppender(&WithMiddleware{
 			appender:          metrics.PrometheusHandler{},
 			routerMiddlewares: chain,
 		})
 	}
-	}
 
 	return aggregator
 }

server/router/route_appender_aggregator_test.go

@@ -17,7 +17,7 @@ type ChainBuilderMock struct {
 	middles map[string]alice.Constructor
 }
 
-func (c *ChainBuilderMock) BuildChain(ctx context.Context, middles []string) (*alice.Chain, error) {
+func (c *ChainBuilderMock) BuildChain(ctx context.Context, middles []string) *alice.Chain {
 	chain := alice.New()
 
 	for _, mName := range middles {
@@ -26,7 +26,7 @@ func (c *ChainBuilderMock) BuildChain(ctx context.Context, middles []string) (*a
 		}
 	}
 
-	return &chain, nil
+	return &chain
 }
 
 func TestNewRouteAppenderAggregator(t *testing.T) {
@@ -61,7 +61,7 @@ func TestNewRouteAppenderAggregator(t *testing.T) {
 			expected: map[string]int{
 				"/wrong": http.StatusBadGateway,
 				"/ping":  http.StatusOK,
-				//"/.well-known/acme-challenge/token": http.StatusNotFound, // FIXME
+				// "/.well-known/acme-challenge/token": http.StatusNotFound, // FIXME
 				"/api/providers": http.StatusUnauthorized,
 			},
 		},

server/router/router.go

@@ -13,6 +13,7 @@ import (
 	"github.com/containous/traefik/middlewares/recovery"
 	"github.com/containous/traefik/middlewares/tracing"
 	"github.com/containous/traefik/responsemodifiers"
+	"github.com/containous/traefik/server/internal"
 	"github.com/containous/traefik/server/middleware"
 	"github.com/containous/traefik/server/service"
 )
@@ -104,9 +105,11 @@ func (m *Manager) buildEntryPointHandler(ctx context.Context, configs map[string
 		SkipClean(true)
 
 	for routerName, routerConfig := range configs {
-		ctx = log.With(ctx, log.Str(log.RouterName, routerName))
+		ctx := log.With(ctx, log.Str(log.RouterName, routerName))
 		logger := log.FromContext(ctx)
 
+		ctx = internal.AddProviderInContext(ctx, routerName)
+
 		handler, err := m.buildRouterHandler(ctx, routerName)
 		if err != nil {
 			logger.Error(err)
@@ -166,10 +169,7 @@ func (m *Manager) buildHandler(ctx context.Context, router *config.Router, route
 		return nil, err
 	}
 
-	mHandler, err := m.middlewaresBuilder.BuildChain(ctx, router.Middlewares)
-	if err != nil {
-		return nil, err
-	}
+	mHandler := m.middlewaresBuilder.BuildChain(ctx, router.Middlewares)
 
 	alHandler := func(next http.Handler) (http.Handler, error) {
 		return accesslog.NewFieldHandler(next, accesslog.ServiceName, router.Service, accesslog.AddServiceFields), nil

server/router/router_test.go

@@ -209,6 +209,102 @@ func TestRouterManager_Get(t *testing.T) {
 				},
 			},
 		},
+		{
+			desc: "no middleware with provider name",
+			routersConfig: map[string]*config.Router{
+				"provider-1.foo": {
+					EntryPoints: []string{"web"},
+					Service:     "foo-service",
+					Rule:        "Host:foo.bar",
+				},
+			},
+			serviceConfig: map[string]*config.Service{
+				"provider-1.foo-service": {
+					LoadBalancer: &config.LoadBalancerService{
+						Servers: []config.Server{
+							{
+								URL:    server.URL,
+								Weight: 1,
+							},
+						},
+						Method: "wrr",
+					},
+				},
+			},
+			entryPoints: []string{"web"},
+			expected:    ExpectedResult{StatusCode: http.StatusOK},
+		},
+		{
+			desc: "no middleware with specified provider name",
+			routersConfig: map[string]*config.Router{
+				"provider-1.foo": {
+					EntryPoints: []string{"web"},
+					Service:     "provider-2.foo-service",
+					Rule:        "Host:foo.bar",
+				},
+			},
+			serviceConfig: map[string]*config.Service{
+				"provider-2.foo-service": {
+					LoadBalancer: &config.LoadBalancerService{
+						Servers: []config.Server{
+							{
+								URL:    server.URL,
+								Weight: 1,
+							},
+						},
+						Method: "wrr",
+					},
+				},
+			},
+			entryPoints: []string{"web"},
+			expected:    ExpectedResult{StatusCode: http.StatusOK},
+		},
+		{
+			desc: "middleware: chain with provider name",
+			routersConfig: map[string]*config.Router{
+				"provider-1.foo": {
+					EntryPoints: []string{"web"},
+					Middlewares: []string{"provider-2.chain-middle", "headers-middle"},
+					Service:     "foo-service",
+					Rule:        "Host:foo.bar",
+				},
+			},
+			serviceConfig: map[string]*config.Service{
+				"provider-1.foo-service": {
+					LoadBalancer: &config.LoadBalancerService{
+						Servers: []config.Server{
+							{
+								URL:    server.URL,
+								Weight: 1,
+							},
+						},
+						Method: "wrr",
+					},
+				},
+			},
+			middlewaresConfig: map[string]*config.Middleware{
+				"provider-2.chain-middle": {
+					Chain: &config.Chain{Middlewares: []string{"auth-middle"}},
+				},
+				"provider-2.auth-middle": {
+					BasicAuth: &config.BasicAuth{
+						Users: []string{"toto:titi"},
+					},
+				},
+				"provider-1.headers-middle": {
+					Headers: &config.Headers{
+						CustomRequestHeaders: map[string]string{"X-Apero": "beer"},
+					},
+				},
+			},
+			entryPoints: []string{"web"},
+			expected: ExpectedResult{
+				StatusCode: http.StatusUnauthorized,
+				RequestHeaders: map[string]string{
+					"X-Apero": "",
+				},
+			},
+		},
 	}
 
 	for _, test := range testCases {

server/server_configuration.go

@@ -76,28 +76,7 @@ func (s *Server) loadConfig(configurations config.Configurations) (map[string]ht
 
 	ctx := context.TODO()
 
-	// FIXME manage duplicates
-	conf := config.Configuration{
-		Routers:     make(map[string]*config.Router),
-		Middlewares: make(map[string]*config.Middleware),
-		Services:    make(map[string]*config.Service),
-	}
-	for _, config := range configurations {
-		for key, value := range config.Middlewares {
-			conf.Middlewares[key] = value
-		}
-
-		for key, value := range config.Services {
-			conf.Services[key] = value
-		}
-
-		for key, value := range config.Routers {
-			conf.Routers[key] = value
-		}
-
-		conf.TLS = append(conf.TLS, config.TLS...)
-	}
-
+	conf := mergeConfiguration(configurations)
 	handlers := s.applyConfiguration(ctx, conf)
 
 	// Get new certificates list sorted per entry points

server/service/service.go

@@ -16,6 +16,7 @@ import (
 	"github.com/containous/traefik/middlewares/emptybackendhandler"
 	"github.com/containous/traefik/old/middlewares/pipelining"
 	"github.com/containous/traefik/server/cookie"
+	"github.com/containous/traefik/server/internal"
 	"github.com/vulcand/oxy/forward"
 	"github.com/vulcand/oxy/roundrobin"
 )
@@ -58,9 +59,11 @@ type Manager struct {
 func (m *Manager) Build(rootCtx context.Context, serviceName string, responseModifier func(*http.Response) error) (http.Handler, error) {
 	ctx := log.With(rootCtx, log.Str(log.ServiceName, serviceName))
 
-	// TODO refactor ?
+	serviceName = internal.GetQualifiedName(ctx, serviceName)
+	ctx = internal.AddProviderInContext(ctx, serviceName)
+
 	if conf, ok := m.configs[serviceName]; ok {
-		// FIXME Should handle multiple service types
+		// TODO Should handle multiple service types
 		if conf.LoadBalancer != nil {
 			return m.getLoadBalancerServiceHandler(ctx, serviceName, conf.LoadBalancer, responseModifier)
 		}

server/service/service_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"github.com/containous/traefik/config"
+	"github.com/containous/traefik/server/internal"
 	"github.com/containous/traefik/testhelpers"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -324,4 +325,59 @@ func TestGetLoadBalancerServiceHandler(t *testing.T) {
 	}
 }
 
+func TestManager_Build(t *testing.T) {
+	testCases := []struct {
+		desc         string
+		serviceName  string
+		configs      map[string]*config.Service
+		providerName string
+	}{
+		{
+			desc:        "Simple service name",
+			serviceName: "serviceName",
+			configs: map[string]*config.Service{
+				"serviceName": {
+					LoadBalancer: &config.LoadBalancerService{Method: "wrr"},
+				},
+			},
+		},
+		{
+			desc:        "Service name with provider",
+			serviceName: "provider-1.serviceName",
+			configs: map[string]*config.Service{
+				"provider-1.serviceName": {
+					LoadBalancer: &config.LoadBalancerService{Method: "wrr"},
+				},
+			},
+		},
+		{
+			desc:        "Service name with provider in context",
+			serviceName: "serviceName",
+			configs: map[string]*config.Service{
+				"provider-1.serviceName": {
+					LoadBalancer: &config.LoadBalancerService{Method: "wrr"},
+				},
+			},
+			providerName: "provider-1",
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			manager := NewManager(test.configs, http.DefaultTransport)
+
+			ctx := context.Background()
+			if len(test.providerName) > 0 {
+				ctx = internal.AddProviderInContext(ctx, test.providerName+".foobar")
+			}
+
+			_, err := manager.Build(ctx, test.serviceName, nil)
+			require.NoError(t, err)
+		})
+	}
+}
+
 // FIXME Add healthcheck tests