Don't add TCP proxy when error occurs during creation.

pkg/server/router/router.go

@@ -75,15 +75,6 @@ func (m *Manager) BuildHandlers(rootCtx context.Context, entryPoints []string, t
 	return entryPointHandlers
 }
 
-func contains(entryPoints []string, entryPointName string) bool {
-	for _, name := range entryPoints {
-		if name == entryPointName {
-			return true
-		}
-	}
-	return false
-}
-
 func (m *Manager) filteredRouters(ctx context.Context, entryPoints []string, tls bool) map[string]map[string]*config.Router {
 	entryPointsRouters := make(map[string]map[string]*config.Router)
 
@@ -121,11 +112,9 @@ func (m *Manager) buildEntryPointHandler(ctx context.Context, configs map[string
 	}
 
 	for routerName, routerConfig := range configs {
-		ctxRouter := log.With(ctx, log.Str(log.RouterName, routerName))
+		ctxRouter := log.With(internal.AddProviderInContext(ctx, routerName), log.Str(log.RouterName, routerName))
 		logger := log.FromContext(ctxRouter)
 
-		ctxRouter = internal.AddProviderInContext(ctxRouter, routerName)
-
 		handler, err := m.buildRouterHandler(ctxRouter, routerName)
 		if err != nil {
 			logger.Error(err)
@@ -197,3 +186,12 @@ func (m *Manager) buildHTTPHandler(ctx context.Context, router *config.Router, r
 
 	return alice.New().Extend(*mHandler).Append(tHandler).Then(sHandler)
 }
+
+func contains(entryPoints []string, entryPointName string) bool {
+	for _, name := range entryPoints {
+		if name == entryPointName {
+			return true
+		}
+	}
+	return false
+}

pkg/server/router/tcp/router.go

@@ -62,14 +62,12 @@ func (m *Manager) BuildHandlers(rootCtx context.Context, entryPoints []string) m
 
 func (m *Manager) buildEntryPointHandler(ctx context.Context, configs map[string]*config.TCPRouter, handlerHTTP http.Handler, handlerHTTPS http.Handler) (*tcp.Router, error) {
 	router := &tcp.Router{}
-
 	router.HTTPHandler(handlerHTTP)
 	router.HTTPSHandler(handlerHTTPS, m.tlsConfig)
-	for routerName, routerConfig := range configs {
-		ctxRouter := log.With(ctx, log.Str(log.RouterName, routerName))
-		logger := log.FromContext(ctxRouter)
 
-		ctxRouter = internal.AddProviderInContext(ctxRouter, routerName)
+	for routerName, routerConfig := range configs {
+		ctxRouter := log.With(internal.AddProviderInContext(ctx, routerName), log.Str(log.RouterName, routerName))
+		logger := log.FromContext(ctxRouter)
 
 		handler, err := m.serviceManager.BuildTCP(ctxRouter, routerConfig.Service)
 		if err != nil {
@@ -79,18 +77,18 @@ func (m *Manager) buildEntryPointHandler(ctx context.Context, configs map[string
 
 		domains, err := rules.ParseHostSNI(routerConfig.Rule)
 		if err != nil {
-			log.WithoutContext().Debugf("Unknown rule %s", routerConfig.Rule)
+			logger.Debugf("Unknown rule %s", routerConfig.Rule)
 			continue
 		}
+
 		for _, domain := range domains {
-			log.WithoutContext().Debugf("Add route %s on TCP", domain)
+			logger.Debugf("Add route %s on TCP", domain)
 			switch {
 			case routerConfig.TLS != nil:
 				if routerConfig.TLS.Passthrough {
 					router.AddRoute(domain, handler)
 				} else {
 					router.AddRouteTLS(domain, handler, m.tlsConfig)
-
 				}
 			case domain == "*":
 				router.AddCatchAllNoTLS(handler)
@@ -103,15 +101,6 @@ func (m *Manager) buildEntryPointHandler(ctx context.Context, configs map[string
 	return router, nil
 }
 
-func contains(entryPoints []string, entryPointName string) bool {
-	for _, name := range entryPoints {
-		if name == entryPointName {
-			return true
-		}
-	}
-	return false
-}
-
 func (m *Manager) filteredRouters(ctx context.Context, entryPoints []string) map[string]map[string]*config.TCPRouter {
 	entryPointsRouters := make(map[string]map[string]*config.TCPRouter)
 
@@ -120,6 +109,7 @@ func (m *Manager) filteredRouters(ctx context.Context, entryPoints []string) map
 		if len(eps) == 0 {
 			eps = entryPoints
 		}
+
 		for _, entryPointName := range eps {
 			if !contains(entryPoints, entryPointName) {
 				log.FromContext(log.With(ctx, log.Str(log.EntryPointName, entryPointName))).
@@ -137,3 +127,12 @@ func (m *Manager) filteredRouters(ctx context.Context, entryPoints []string) map
 
 	return entryPointsRouters
 }
+
+func contains(entryPoints []string, entryPointName string) bool {
+	for _, name := range entryPoints {
+		if name == entryPointName {
+			return true
+		}
+	}
+	return false
+}

pkg/server/service/tcp/service.go

@@ -25,32 +25,41 @@ func NewManager(configs map[string]*config.TCPService) *Manager {
 
 // BuildTCP Creates a tcp.Handler for a service configuration.
 func (m *Manager) BuildTCP(rootCtx context.Context, serviceName string) (tcp.Handler, error) {
-	ctx := log.With(rootCtx, log.Str(log.ServiceName, serviceName))
+	serviceQualifiedName := internal.GetQualifiedName(rootCtx, serviceName)
+	ctx := internal.AddProviderInContext(rootCtx, serviceQualifiedName)
+	ctx = log.With(ctx, log.Str(log.ServiceName, serviceName))
 
-	serviceName = internal.GetQualifiedName(ctx, serviceName)
+	conf, ok := m.configs[serviceQualifiedName]
-	ctx = internal.AddProviderInContext(ctx, serviceName)
+	if !ok {
+		return nil, fmt.Errorf("the service %q does not exits", serviceQualifiedName)
+	}
+
+	if conf.LoadBalancer == nil {
+		return nil, fmt.Errorf("the service %q doesn't have any TCP load balancer", serviceQualifiedName)
+	}
+
+	logger := log.FromContext(ctx)
 
-	if conf, ok := m.configs[serviceName]; ok {
 	// FIXME Check if the service is declared multiple times with different types
-		if conf.LoadBalancer != nil {
 	loadBalancer := tcp.NewRRLoadBalancer()
 
-			var handler tcp.Handler
 	for _, server := range conf.LoadBalancer.Servers {
-				_, err := parseIP(server.Address)
+		if _, err := parseIP(server.Address); err != nil {
-				if err == nil {
+			logger.Errorf("Invalid IP address for a %q server %q: %v", serviceQualifiedName, server.Address, err)
-					handler, _ = tcp.NewProxy(server.Address)
+			continue
+		}
+
+		handler, err := tcp.NewProxy(server.Address)
+		if err != nil {
+			logger.Errorf("In service %q server %q: %v", serviceQualifiedName, server.Address, err)
+			continue
+		}
+
 		loadBalancer.AddServer(handler)
-				} else {
-					log.FromContext(ctx).Errorf("Invalid IP address for a %s server %s: %v", serviceName, server.Address, err)
-				}
 	}
+
 	return loadBalancer, nil
 }
-		return nil, fmt.Errorf("the service %q doesn't have any TCP load balancer", serviceName)
-	}
-	return nil, fmt.Errorf("the service %q does not exits", serviceName)
-}
 
 func parseIP(s string) (string, error) {
 	ip, _, err := net.SplitHostPort(s)

pkg/server/service/tcp/service_test.go

@@ -0,0 +1,82 @@
+package tcp
+
+import (
+	"context"
+	"testing"
+
+	"github.com/containous/traefik/pkg/config"
+	"github.com/stretchr/testify/require"
+)
+
+func TestManager_BuildTCP(t *testing.T) {
+	testCases := []struct {
+		desc          string
+		serviceName   string
+		configs       map[string]*config.TCPService
+		expectedError string
+	}{
+		{
+			desc:          "without configuration",
+			serviceName:   "test",
+			configs:       nil,
+			expectedError: `the service "test" does not exits`,
+		},
+		{
+			desc:        "missing lb configuration",
+			serviceName: "test",
+			configs: map[string]*config.TCPService{
+				"test": {},
+			},
+			expectedError: `the service "test" doesn't have any TCP load balancer`,
+		},
+		{
+			desc:        "no such host",
+			serviceName: "test",
+			configs: map[string]*config.TCPService{
+				"test": {
+					LoadBalancer: &config.TCPLoadBalancerService{
+						Servers: []config.TCPServer{
+							{Address: "test:31"},
+						},
+					},
+				},
+			},
+		},
+		{
+			desc:        "invalid IP address",
+			serviceName: "test",
+			configs: map[string]*config.TCPService{
+				"test": {
+					LoadBalancer: &config.TCPLoadBalancerService{
+						Servers: []config.TCPServer{
+							{Address: "foobar"},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			manager := NewManager(test.configs)
+
+			handler, err := manager.BuildTCP(context.Background(), test.serviceName)
+
+			if test.expectedError != "" {
+				if err == nil {
+					require.Error(t, err)
+				} else {
+					require.EqualError(t, err, test.expectedError)
+					require.Nil(t, handler)
+				}
+			} else {
+				require.NoError(t, err)
+				require.NotNil(t, handler)
+			}
+		})
+	}
+}

pkg/tcp/proxy.go

@@ -18,15 +18,15 @@ func NewProxy(address string) (*Proxy, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &Proxy{
+
-		target: tcpAddr,
+	return &Proxy{target: tcpAddr}, nil
-	}, nil
 }
 
 // ServeTCP forwards the connection to a service
 func (p *Proxy) ServeTCP(conn net.Conn) {
 	log.Debugf("Handling connection from %s", conn.RemoteAddr())
 	defer conn.Close()
+
 	connBackend, err := net.DialTCP("tcp", nil, p.target)
 	if err != nil {
 		log.Errorf("Error while connection to backend: %v", err)

pkg/tcp/rr_load_balancer.go

@@ -21,6 +21,11 @@ func NewRRLoadBalancer() *RRLoadBalancer {
 
 // ServeTCP forwards the connection to the right service
 func (r *RRLoadBalancer) ServeTCP(conn net.Conn) {
+	if len(r.servers) == 0 {
+		log.WithoutContext().Error("no available server")
+		return
+	}
+
 	r.next().ServeTCP(conn)
 }
 
@@ -38,6 +43,7 @@ func (r *RRLoadBalancer) next() Handler {
 		r.current = 0
 		log.Debugf("Load balancer: going back to the first available server")
 	}
+
 	handler := r.servers[r.current]
 	r.current++
 	return handler