Merge branch v2.3 into master

pkg/middlewares/redirect/redirect.go

@@ -1,9 +1,6 @@
 package redirect
 
 import (
-	"bytes"
-	"html/template"
-	"io"
 	"net/http"
 	"net/url"
 	"regexp"
@@ -47,24 +44,17 @@ func (r *redirect) GetTracingInformation() (string, ext.SpanKindEnum) {
 func (r *redirect) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	oldURL := rawURL(req)
 
-	// If the Regexp doesn't match, skip to the next handler
+	// If the Regexp doesn't match, skip to the next handler.
 	if !r.regex.MatchString(oldURL) {
 		r.next.ServeHTTP(rw, req)
 		return
 	}
 
-	// apply a rewrite regexp to the URL
+	// Apply a rewrite regexp to the URL.
 	newURL := r.regex.ReplaceAllString(oldURL, r.replacement)
 
-	// replace any variables that may be in there
-	rewrittenURL := &bytes.Buffer{}
-	if err := applyString(newURL, rewrittenURL, req); err != nil {
-		r.errHandler.ServeHTTP(rw, req, err)
-		return
-	}
-
-	// parse the rewritten URL and replace request URL with it
-	parsedURL, err := url.Parse(rewrittenURL.String())
+	// Parse the rewritten URL and replace request URL with it.
+	parsedURL, err := url.Parse(newURL)
 	if err != nil {
 		r.errHandler.ServeHTTP(rw, req, err)
 		return
@@ -78,7 +68,7 @@ func (r *redirect) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 
 	req.URL = parsedURL
 
-	// make sure the request URI corresponds the rewritten URL
+	// Make sure the request URI corresponds the rewritten URL.
 	req.RequestURI = req.URL.RequestURI()
 	r.next.ServeHTTP(rw, req)
 }
@@ -138,14 +128,3 @@ func rawURL(req *http.Request) string {
 
 	return strings.Join([]string{scheme, "://", host, port, uri}, "")
 }
-
-func applyString(in string, out io.Writer, req *http.Request) error {
-	t, err := template.New("t").Parse(in)
-	if err != nil {
-		return err
-	}
-
-	data := struct{ Request *http.Request }{Request: req}
-
-	return t.Execute(out, data)
-}

pkg/middlewares/redirect/redirect_regex_test.go

@@ -10,7 +10,6 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
-	"github.com/traefik/traefik/v2/pkg/testhelpers"
 )
 
 func TestRedirectRegexHandler(t *testing.T) {
@@ -35,16 +34,6 @@ func TestRedirectRegexHandler(t *testing.T) {
 			expectedURL:    "https://foobar.com:443",
 			expectedStatus: http.StatusFound,
 		},
-		{
-			desc: "use request header",
-			config: dynamic.RedirectRegex{
-				Regex:       `^(?:http?:\/\/)(foo)(\.com)(:\d+)(.*)$`,
-				Replacement: `https://${1}{{ .Request.Header.Get "X-Foo" }}$2:443$4`,
-			},
-			url:            "http://foo.com:80",
-			expectedURL:    "https://foobar.com:443",
-			expectedStatus: http.StatusFound,
-		},
 		{
 			desc: "URL doesn't match regex",
 			config: dynamic.RedirectRegex{
@@ -186,7 +175,7 @@ func TestRedirectRegexHandler(t *testing.T) {
 					method = test.method
 				}
 
-				req := testhelpers.MustNewRequest(method, test.url, nil)
+				req := httptest.NewRequest(method, test.url, nil)
 				if test.secured {
 					req.TLS = &tls.ConnectionState{}
 				}

pkg/provider/kubernetes/crd/fixtures/services.yml

@@ -119,6 +119,35 @@ subsets:
       - name: websecure2
         port: 8443
 
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoami-ipv6
+  namespace: default
+
+spec:
+  ports:
+    - name: web
+      port: 8080
+  selector:
+    app: traefiklabs
+    task: whoami-ipv6
+
+---
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: whoami-ipv6
+  namespace: default
+
+subsets:
+  - addresses:
+      - ip: "2001:db8:85a3:8d3:1319:8a2e:370:7348"
+    ports:
+      - name: web
+        port: 8080
+
 ---
 apiVersion: v1
 kind: Service
@@ -157,5 +186,46 @@ spec:
       protocol: TCP
       port: 443
 
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: external-svc-with-ipv6
+  namespace: default
+spec:
+  externalName: "2001:db8:85a3:8d3:1319:8a2e:370:7347"
+  type: ExternalName
+  ports:
+    - name: http
+      protocol: TCP
+      port: 8080
 
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoami-svc
+  namespace: cross-ns
 
+spec:
+  ports:
+    - name: web
+      port: 80
+  selector:
+    app: traefiklabs
+    task: whoami
+
+---
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: whoami-svc
+  namespace: cross-ns
+
+subsets:
+  - addresses:
+      - ip: 10.10.0.1
+      - ip: 10.10.0.2
+    ports:
+      - name: web
+        port: 80

pkg/provider/kubernetes/crd/fixtures/tcp/services.yml

@@ -132,6 +132,36 @@ subsets:
       - name: myapp4
         port: 8084
 
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoamitcp-ipv6
+  namespace: default
+
+spec:
+  ports:
+    - name: myapp-ipv6
+      port: 8080
+  selector:
+    app: traefiklabs
+    task: whoamitcp-ipv6
+
+---
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: whoamitcp-ipv6
+  namespace: default
+
+subsets:
+  - addresses:
+      - ip: "fd00:10:244:0:1::3"
+      - ip: "2001:db8:85a3:8d3:1319:8a2e:370:7348"
+    ports:
+      - name: myapp-ipv6
+        port: 8080
+
 ---
 apiVersion: v1
 kind: Service
@@ -167,4 +197,44 @@ spec:
   type: ExternalName
   ports:
     - name: http
-      protocol: TCP
+      protocol: TCP
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: external.service.with.ipv6
+  namespace: default
+spec:
+  externalName: "fe80::200:5aee:feaa:20a2"
+  type: ExternalName
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoamitcp-cross-ns
+  namespace: cross-ns
+
+spec:
+  ports:
+    - name: myapp
+      port: 8000
+  selector:
+    app: traefiklabs
+    task: whoamitcp
+
+---
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: whoamitcp-cross-ns
+  namespace: cross-ns
+
+subsets:
+  - addresses:
+      - ip: 10.10.0.1
+      - ip: 10.10.0.2
+    ports:
+      - name: myapp
+        port: 8000

pkg/provider/kubernetes/crd/fixtures/tcp/with_cross_namespace.yml

@@ -0,0 +1,16 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRouteTCP
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - match: HostSNI(`foo.com`)
+    services:
+    - name: whoamitcp-cross-ns
+      namespace: cross-ns
+      port: 8000

pkg/provider/kubernetes/crd/fixtures/tcp/with_ipv6.yml

@@ -0,0 +1,17 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRouteTCP
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - match: HostSNI(`*`)
+    services:
+    - name: whoamitcp-ipv6
+      port: 8080
+    - name: external.service.with.ipv6
+      port: 8080

pkg/provider/kubernetes/crd/fixtures/udp/services.yml

@@ -101,3 +101,62 @@ subsets:
     ports:
       - name: myapp4
         port: 8084
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoamiudp-ipv6
+  namespace: default
+
+spec:
+  ports:
+    - name: myapp-ipv6
+      port: 8080
+  selector:
+    app: traefiklabs
+    task: whoamiudp-ipv6
+
+---
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: whoamiudp-ipv6
+  namespace: default
+
+subsets:
+  - addresses:
+      - ip: "fd00:10:244:0:1::3"
+    ports:
+      - name: myapp-ipv6
+        port: 8080
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoamiudp-cross-ns
+  namespace: cross-ns
+
+spec:
+  ports:
+    - name: myapp
+      port: 8000
+  selector:
+    app: traefiklabs
+    task: whoamiudp
+
+---
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: whoamiudp-cross-ns
+  namespace: cross-ns
+
+subsets:
+  - addresses:
+      - ip: 10.10.0.1
+      - ip: 10.10.0.2
+    ports:
+      - name: myapp
+        port: 8000

pkg/provider/kubernetes/crd/fixtures/udp/with_cross_namespace.yml

@@ -0,0 +1,15 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRouteUDP
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - services:
+    - name: whoamiudp-cross-ns
+      namespace: cross-ns
+      port: 8000

pkg/provider/kubernetes/crd/fixtures/udp/with_ipv6.yml

@@ -0,0 +1,14 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRouteUDP
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - services:
+    - name: whoamiudp-ipv6
+      port: 8080

pkg/provider/kubernetes/crd/fixtures/with_cross_namespace.yml

@@ -0,0 +1,91 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRoute
+metadata:
+  name: cross-ns-route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - match: Host(`foo.com`) && PathPrefix(`/bar`)
+    kind: Rule
+    priority: 12
+    services:
+    - name: whoami-svc
+      namespace: cross-ns
+      port: 80
+    - name: tr-svc-wrr1
+      kind: TraefikService
+    - name: tr-svc-wrr2
+      namespace: cross-ns
+      kind: TraefikService
+    - name: tr-svc-mirror1
+      kind: TraefikService
+    - name: tr-svc-mirror2
+      namespace: cross-ns
+      kind: TraefikService
+
+---
+apiVersion: traefik.containo.us/v1alpha1
+kind: TraefikService
+metadata:
+  name: tr-svc-wrr1
+  namespace: default
+
+spec:
+  weighted:
+    services:
+      - name: whoami-svc
+        namespace: cross-ns
+        weight: 1
+        port: 80
+
+---
+apiVersion: traefik.containo.us/v1alpha1
+kind: TraefikService
+metadata:
+  name: tr-svc-wrr2
+  namespace: cross-ns
+
+spec:
+  weighted:
+    services:
+      - name: whoami-svc
+        weight: 1
+        port: 80
+
+---
+apiVersion: traefik.containo.us/v1alpha1
+kind: TraefikService
+metadata:
+  name: tr-svc-mirror1
+  namespace: default
+
+spec:
+  mirroring:
+    name: whoami
+    port: 80
+    mirrors:
+      - name: whoami-svc
+        namespace: cross-ns
+        percent: 20
+        port: 80
+
+---
+apiVersion: traefik.containo.us/v1alpha1
+kind: TraefikService
+metadata:
+  name: tr-svc-mirror2
+  namespace: cross-ns
+
+spec:
+  mirroring:
+    name: whoami-svc
+    port: 80
+    mirrors:
+      - name: whoami-svc
+        namespace: cross-ns
+        percent: 20
+        port: 80

pkg/provider/kubernetes/crd/fixtures/with_ipv6.yml

@@ -0,0 +1,18 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRoute
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+    - match: Host(`foo.com`) && PathPrefix(`/bar`)
+      kind: Rule
+      services:
+        - name: whoami-ipv6
+          port: 8080
+        - name: external-svc-with-ipv6
+          port: 8080

pkg/provider/kubernetes/crd/fixtures/with_middleware_cross_namespace.yml

@@ -0,0 +1,58 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRoute
+metadata:
+  name: test-crossnamespace.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - match: Host(`foo.com`) && PathPrefix(`/bar`)
+    kind: Rule
+    priority: 12
+    services:
+    - name: whoami
+      namespace: default
+      port: 80
+    middlewares:
+    - name: stripprefix
+      namespace: cross-ns
+  - match: Host(`foo.com`) && PathPrefix(`/bir`)
+    kind: Rule
+    priority: 12
+    services:
+    - name: whoami
+      namespace: default
+      port: 80
+    middlewares:
+    - name: test-errorpage
+
+---
+apiVersion: traefik.containo.us/v1alpha1
+kind: Middleware
+metadata:
+  name: stripprefix
+  namespace: cross-ns
+
+spec:
+  stripPrefix:
+    prefixes:
+      - /stripit
+
+---
+apiVersion: traefik.containo.us/v1alpha1
+kind: Middleware
+metadata:
+  name: test-errorpage
+  namespace: default
+spec:
+  errors:
+    status:
+      - 500-599
+    query: /{status}.html
+    service:
+      name: whoami-svc
+      namespace: cross-ns
+      port: 80

pkg/provider/kubernetes/crd/kubernetes.go

@@ -43,12 +43,18 @@ type Provider struct {
 	CertAuthFilePath       string          `description:"Kubernetes certificate authority file path (not needed for in-cluster client)." json:"certAuthFilePath,omitempty" toml:"certAuthFilePath,omitempty" yaml:"certAuthFilePath,omitempty"`
 	DisablePassHostHeaders bool            `description:"Kubernetes disable PassHost Headers." json:"disablePassHostHeaders,omitempty" toml:"disablePassHostHeaders,omitempty" yaml:"disablePassHostHeaders,omitempty" export:"true"`
 	Namespaces             []string        `description:"Kubernetes namespaces." json:"namespaces,omitempty" toml:"namespaces,omitempty" yaml:"namespaces,omitempty" export:"true"`
+	AllowCrossNamespace    *bool           `description:"Allow cross namespace resource reference." json:"allowCrossNamespace,omitempty" toml:"allowCrossNamespace,omitempty" yaml:"allowCrossNamespace,omitempty" export:"true"`
 	LabelSelector          string          `description:"Kubernetes label selector to use." json:"labelSelector,omitempty" toml:"labelSelector,omitempty" yaml:"labelSelector,omitempty" export:"true"`
 	IngressClass           string          `description:"Value of kubernetes.io/ingress.class annotation to watch for." json:"ingressClass,omitempty" toml:"ingressClass,omitempty" yaml:"ingressClass,omitempty" export:"true"`
 	ThrottleDuration       ptypes.Duration `description:"Ingress refresh throttle duration" json:"throttleDuration,omitempty" toml:"throttleDuration,omitempty" yaml:"throttleDuration,omitempty" export:"true"`
 	lastConfiguration      safe.Safe
 }
 
+// SetDefaults sets the default values.
+func (p *Provider) SetDefaults() {
+	p.AllowCrossNamespace = func(b bool) *bool { return &b }(true)
+}
+
 func (p *Provider) newK8sClient(ctx context.Context) (*clientWrapper, error) {
 	_, err := labels.Parse(p.LabelSelector)
 	if err != nil {
@@ -98,6 +104,10 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
 		return err
 	}
 
+	if p.AllowCrossNamespace == nil || *p.AllowCrossNamespace {
+		logger.Warn("Cross-namespace reference between IngressRoutes and resources is enabled, please ensure that this is expected (see AllowCrossNamespace option)")
+	}
+
 	pool.GoCtx(func(ctxPool context.Context) {
 		operation := func() error {
 			eventsChan, err := k8sClient.WatchAll(p.Namespaces, ctxPool.Done())
@@ -197,7 +207,7 @@ func (p *Provider) loadConfigurationFromCRD(ctx context.Context, client Client)
 			continue
 		}
 
-		errorPage, errorPageService, err := createErrorPageMiddleware(client, middleware.Namespace, middleware.Spec.Errors)
+		errorPage, errorPageService, err := p.createErrorPageMiddleware(client, middleware.Namespace, middleware.Spec.Errors)
 		if err != nil {
 			log.FromContext(ctxMid).Errorf("Error while reading error page middleware: %v", err)
 			continue
@@ -236,7 +246,7 @@ func (p *Provider) loadConfigurationFromCRD(ctx context.Context, client Client)
 		}
 	}
 
-	cb := configBuilder{client}
+	cb := configBuilder{client, p.AllowCrossNamespace}
 
 	for _, service := range client.GetTraefikServices() {
 		err := cb.buildTraefikService(ctx, service, conf.HTTP.Services)
@@ -346,7 +356,7 @@ func getServicePort(svc *corev1.Service, port int32) (*corev1.ServicePort, error
 	return &corev1.ServicePort{Port: port}, nil
 }
 
-func createErrorPageMiddleware(client Client, namespace string, errorPage *v1alpha1.ErrorPage) (*dynamic.ErrorPage, *dynamic.Service, error) {
+func (p *Provider) createErrorPageMiddleware(client Client, namespace string, errorPage *v1alpha1.ErrorPage) (*dynamic.ErrorPage, *dynamic.Service, error) {
 	if errorPage == nil {
 		return nil, nil, nil
 	}
@@ -356,7 +366,7 @@ func createErrorPageMiddleware(client Client, namespace string, errorPage *v1alp
 		Query:  errorPage.Query,
 	}
 
-	balancerServerHTTP, err := configBuilder{client}.buildServersLB(namespace, errorPage.Service.LoadBalancerSpec)
+	balancerServerHTTP, err := configBuilder{client, p.AllowCrossNamespace}.buildServersLB(namespace, errorPage.Service.LoadBalancerSpec)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -816,3 +826,8 @@ func throttleEvents(ctx context.Context, throttleDuration time.Duration, pool *s
 
 	return eventsChanBuffered
 }
+
+func isNamespaceAllowed(allowCrossNamespace *bool, parentNamespace, namespace string) bool {
+	// If allowCrossNamespace option is not defined the default behavior is to allow cross namespace references.
+	return allowCrossNamespace == nil || *allowCrossNamespace || parentNamespace == namespace
+}

pkg/provider/kubernetes/crd/kubernetes_http.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net"
+	"strconv"
 	"strings"
 
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
@@ -47,7 +49,8 @@ func (p *Provider) loadIngressRouteConfiguration(ctx context.Context, client Cli
 			ingressName = ingressRoute.GenerateName
 		}
 
-		cb := configBuilder{client}
+		cb := configBuilder{client, p.AllowCrossNamespace}
+
 		for _, route := range ingressRoute.Spec.Routes {
 			if route.Kind != "Rule" {
 				logger.Errorf("Unsupported match kind: %s. Only \"Rule\" is supported for now.", route.Kind)
@@ -65,23 +68,10 @@ func (p *Provider) loadIngressRouteConfiguration(ctx context.Context, client Cli
 				continue
 			}
 
-			var mds []string
-			for _, mi := range route.Middlewares {
-				if strings.Contains(mi.Name, providerNamespaceSeparator) {
-					if len(mi.Namespace) > 0 {
-						logger.
-							WithField(log.MiddlewareName, mi.Name).
-							Warnf("namespace %q is ignored in cross-provider context", mi.Namespace)
-					}
-					mds = append(mds, mi.Name)
-					continue
-				}
-
-				ns := mi.Namespace
-				if len(ns) == 0 {
-					ns = ingressRoute.Namespace
-				}
-				mds = append(mds, makeID(ns, mi.Name))
+			mds, err := p.makeMiddlewareKeys(ctx, ingressRoute.Namespace, route.Middlewares)
+			if err != nil {
+				logger.Errorf("Failed to create middleware keys: %v", err)
+				continue
 			}
 
 			normalized := provider.Normalize(makeID(ingressRoute.Namespace, serviceKey))
@@ -152,8 +142,38 @@ func (p *Provider) loadIngressRouteConfiguration(ctx context.Context, client Cli
 	return conf
 }
 
+func (p *Provider) makeMiddlewareKeys(ctx context.Context, ingRouteNamespace string, middlewares []v1alpha1.MiddlewareRef) ([]string, error) {
+	var mds []string
+
+	for _, mi := range middlewares {
+		if strings.Contains(mi.Name, providerNamespaceSeparator) {
+			if len(mi.Namespace) > 0 {
+				log.FromContext(ctx).
+					WithField(log.MiddlewareName, mi.Name).
+					Warnf("namespace %q is ignored in cross-provider context", mi.Namespace)
+			}
+			mds = append(mds, mi.Name)
+			continue
+		}
+
+		ns := ingRouteNamespace
+		if len(mi.Namespace) > 0 {
+			if !isNamespaceAllowed(p.AllowCrossNamespace, ingRouteNamespace, mi.Namespace) {
+				return nil, fmt.Errorf("middleware %s/%s is not in the IngressRoute namespace %s", mi.Namespace, mi.Name, ingRouteNamespace)
+			}
+
+			ns = mi.Namespace
+		}
+
+		mds = append(mds, makeID(ns, mi.Name))
+	}
+
+	return mds, nil
+}
+
 type configBuilder struct {
-	client Client
+	client              Client
+	allowCrossNamespace *bool
 }
 
 // buildTraefikService creates the configuration for the traefik service defined in tService,
@@ -270,7 +290,7 @@ func (c configBuilder) buildServersLB(namespace string, svc v1alpha1.LoadBalance
 	return &dynamic.Service{LoadBalancer: lb}, nil
 }
 
-func (c configBuilder) loadServers(fallbackNamespace string, svc v1alpha1.LoadBalancerSpec) ([]dynamic.Server, error) {
+func (c configBuilder) loadServers(parentNamespace string, svc v1alpha1.LoadBalancerSpec) ([]dynamic.Server, error) {
 	strategy := svc.Strategy
 	if strategy == "" {
 		strategy = roundRobinStrategy
@@ -279,7 +299,11 @@ func (c configBuilder) loadServers(fallbackNamespace string, svc v1alpha1.LoadBa
 		return nil, fmt.Errorf("load balancing strategy %s is not supported", strategy)
 	}
 
-	namespace := namespaceOrFallback(svc, fallbackNamespace)
+	namespace := namespaceOrFallback(svc, parentNamespace)
+
+	if !isNamespaceAllowed(c.allowCrossNamespace, parentNamespace, namespace) {
+		return nil, fmt.Errorf("load balancer service %s/%s is not in the parent resource namespace %s", svc.Namespace, svc.Name, parentNamespace)
+	}
 
 	// If the service uses explicitly the provider suffix
 	sanitizedName := strings.TrimSuffix(svc.Name, providerNamespaceSeparator+providerName)
@@ -303,8 +327,10 @@ func (c configBuilder) loadServers(fallbackNamespace string, svc v1alpha1.LoadBa
 			return nil, err
 		}
 
+		hostPort := net.JoinHostPort(service.Spec.ExternalName, strconv.Itoa(int(svcPort.Port)))
+
 		return append(servers, dynamic.Server{
-			URL: fmt.Sprintf("%s://%s:%d", protocol, service.Spec.ExternalName, svcPort.Port),
+			URL: fmt.Sprintf("%s://%s", protocol, hostPort),
 		}), nil
 	}
 
@@ -338,8 +364,10 @@ func (c configBuilder) loadServers(fallbackNamespace string, svc v1alpha1.LoadBa
 		}
 
 		for _, addr := range subset.Addresses {
+			hostPort := net.JoinHostPort(addr.IP, strconv.Itoa(int(port)))
+
 			servers = append(servers, dynamic.Server{
-				URL: fmt.Sprintf("%s://%s:%d", protocol, addr.IP, port),
+				URL: fmt.Sprintf("%s://%s", protocol, hostPort),
 			})
 		}
 	}
@@ -351,10 +379,14 @@ func (c configBuilder) loadServers(fallbackNamespace string, svc v1alpha1.LoadBa
 // In addition, if the service is a Kubernetes one,
 // it generates and returns the configuration part for such a service,
 // so that the caller can add it to the global config map.
-func (c configBuilder) nameAndService(ctx context.Context, namespaceService string, service v1alpha1.LoadBalancerSpec) (string, *dynamic.Service, error) {
+func (c configBuilder) nameAndService(ctx context.Context, parentNamespace string, service v1alpha1.LoadBalancerSpec) (string, *dynamic.Service, error) {
 	svcCtx := log.With(ctx, log.Str(log.ServiceName, service.Name))
 
-	namespace := namespaceOrFallback(service, namespaceService)
+	namespace := namespaceOrFallback(service, parentNamespace)
+
+	if !isNamespaceAllowed(c.allowCrossNamespace, parentNamespace, namespace) {
+		return "", nil, fmt.Errorf("service %s/%s not in the parent resource namespace %s", service.Namespace, service.Name, parentNamespace)
+	}
 
 	switch {
 	case service.Kind == "" || service.Kind == "Service":

pkg/provider/kubernetes/crd/kubernetes_tcp.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net"
+	"strconv"
 	"strings"
 
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
@@ -53,7 +55,7 @@ func (p *Provider) loadIngressRouteTCPConfiguration(ctx context.Context, client
 			serviceName := makeID(ingressRouteTCP.Namespace, key)
 
 			for _, service := range route.Services {
-				balancerServerTCP, err := createLoadBalancerServerTCP(client, ingressRouteTCP.Namespace, service)
+				balancerServerTCP, err := p.createLoadBalancerServerTCP(client, ingressRouteTCP.Namespace, service)
 				if err != nil {
 					logger.
 						WithField("serviceName", service.Name).
@@ -123,9 +125,13 @@ func (p *Provider) loadIngressRouteTCPConfiguration(ctx context.Context, client
 	return conf
 }
 
-func createLoadBalancerServerTCP(client Client, namespace string, service v1alpha1.ServiceTCP) (*dynamic.TCPService, error) {
-	ns := namespace
+func (p *Provider) createLoadBalancerServerTCP(client Client, parentNamespace string, service v1alpha1.ServiceTCP) (*dynamic.TCPService, error) {
+	ns := parentNamespace
 	if len(service.Namespace) > 0 {
+		if !isNamespaceAllowed(p.AllowCrossNamespace, parentNamespace, service.Namespace) {
+			return nil, fmt.Errorf("tcp service %s/%s is not in the parent resource namespace %s", service.Namespace, service.Name, parentNamespace)
+		}
+
 		ns = service.Namespace
 	}
 
@@ -174,7 +180,7 @@ func loadTCPServers(client Client, namespace string, svc v1alpha1.ServiceTCP) ([
 	var servers []dynamic.TCPServer
 	if service.Spec.Type == corev1.ServiceTypeExternalName {
 		servers = append(servers, dynamic.TCPServer{
-			Address: fmt.Sprintf("%s:%d", service.Spec.ExternalName, svcPort.Port),
+			Address: net.JoinHostPort(service.Spec.ExternalName, strconv.Itoa(int(svcPort.Port))),
 		})
 	} else {
 		endpoints, endpointsExists, endpointsErr := client.GetEndpoints(namespace, svc.Name)
@@ -205,7 +211,7 @@ func loadTCPServers(client Client, namespace string, svc v1alpha1.ServiceTCP) ([
 
 			for _, addr := range subset.Addresses {
 				servers = append(servers, dynamic.TCPServer{
-					Address: fmt.Sprintf("%s:%d", addr.IP, port),
+					Address: net.JoinHostPort(addr.IP, strconv.Itoa(int(port))),
 				})
 			}
 		}

pkg/provider/kubernetes/crd/kubernetes_test.go

@@ -2,15 +2,23 @@ package crd
 
 import (
 	"context"
+	"io/ioutil"
+	"path/filepath"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/traefik/paerser/types"
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
 	"github.com/traefik/traefik/v2/pkg/provider"
+	crdfake "github.com/traefik/traefik/v2/pkg/provider/kubernetes/crd/generated/clientset/versioned/fake"
+	"github.com/traefik/traefik/v2/pkg/provider/kubernetes/crd/traefik/v1alpha1"
+	"github.com/traefik/traefik/v2/pkg/provider/kubernetes/k8s"
 	"github.com/traefik/traefik/v2/pkg/tls"
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	kubefake "k8s.io/client-go/kubernetes/fake"
 )
 
 var _ provider.Provider = (*Provider)(nil)
@@ -1010,6 +1018,129 @@ func TestLoadIngressRouteTCPs(t *testing.T) {
 				TLS: &dynamic.TLSConfiguration{},
 			},
 		},
+		{
+			desc: "Ingress Route with IPv6 backends",
+			paths: []string{
+				"services.yml", "with_ipv6.yml",
+				"tcp/services.yml", "tcp/with_ipv6.yml",
+				"udp/services.yml", "udp/with_ipv6.yml",
+			},
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers: map[string]*dynamic.UDPRouter{
+						"default-test.route-0": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test.route-0",
+						},
+					},
+					Services: map[string]*dynamic.UDPService{
+						"default-test.route-0": {
+							LoadBalancer: &dynamic.UDPServersLoadBalancer{
+								Servers: []dynamic.UDPServer{
+									{
+										Address: "[fd00:10:244:0:1::3]:8080",
+									},
+								},
+							},
+						},
+					},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers: map[string]*dynamic.TCPRouter{
+						"default-test.route-673acf455cb2dab0b43a": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test.route-673acf455cb2dab0b43a",
+							Rule:        "HostSNI(`*`)",
+						},
+					},
+					Services: map[string]*dynamic.TCPService{
+						"default-test.route-673acf455cb2dab0b43a": {
+							Weighted: &dynamic.TCPWeightedRoundRobin{
+								Services: []dynamic.TCPWRRService{
+									{
+										Name:   "default-test.route-673acf455cb2dab0b43a-whoamitcp-ipv6-8080",
+										Weight: func(i int) *int { return &i }(1),
+									},
+									{
+										Name:   "default-test.route-673acf455cb2dab0b43a-external.service.with.ipv6-8080",
+										Weight: func(i int) *int { return &i }(1),
+									},
+								},
+							},
+						},
+						"default-test.route-673acf455cb2dab0b43a-whoamitcp-ipv6-8080": {
+							LoadBalancer: &dynamic.TCPServersLoadBalancer{
+								Servers: []dynamic.TCPServer{
+									{
+										Address: "[fd00:10:244:0:1::3]:8080",
+									},
+									{
+										Address: "[2001:db8:85a3:8d3:1319:8a2e:370:7348]:8080",
+									},
+								},
+							},
+						},
+						"default-test.route-673acf455cb2dab0b43a-external.service.with.ipv6-8080": {
+							LoadBalancer: &dynamic.TCPServersLoadBalancer{
+								Servers: []dynamic.TCPServer{
+									{
+										Address: "[fe80::200:5aee:feaa:20a2]:8080",
+									},
+								},
+							},
+						},
+					},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers: map[string]*dynamic.Router{
+						"default-test-route-6b204d94623b3df4370c": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test-route-6b204d94623b3df4370c",
+							Rule:        "Host(`foo.com`) && PathPrefix(`/bar`)",
+						},
+					},
+					Middlewares: map[string]*dynamic.Middleware{},
+					Services: map[string]*dynamic.Service{
+						"default-whoami-ipv6-8080": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://[2001:db8:85a3:8d3:1319:8a2e:370:7348]:8080",
+									},
+								},
+								PassHostHeader: func(i bool) *bool { return &i }(true),
+							},
+						},
+						"default-external-svc-with-ipv6-8080": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://[2001:db8:85a3:8d3:1319:8a2e:370:7347]:8080",
+									},
+								},
+								PassHostHeader: func(i bool) *bool { return &i }(true),
+							},
+						},
+						"default-test-route-6b204d94623b3df4370c": {
+							Weighted: &dynamic.WeightedRoundRobin{
+								Services: []dynamic.WRRService{
+									{
+										Name:   "default-whoami-ipv6-8080",
+										Weight: func(i int) *int { return &i }(1),
+									},
+									{
+										Name:   "default-external-svc-with-ipv6-8080",
+										Weight: func(i int) *int { return &i }(1),
+									},
+								},
+							},
+						},
+					},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
 	}
 
 	for _, test := range testCases {
@@ -1023,7 +1154,10 @@ func TestLoadIngressRouteTCPs(t *testing.T) {
 			}
 
 			p := Provider{IngressClass: test.ingressClass}
-			conf := p.loadConfigurationFromCRD(context.Background(), newClientMock(test.paths...))
+			p.SetDefaults()
+
+			clientMock := newClientMock(test.paths...)
+			conf := p.loadConfigurationFromCRD(context.Background(), clientMock)
 			assert.Equal(t, test.expected, conf)
 		})
 	}
@@ -3205,7 +3339,10 @@ func TestLoadIngressRoutes(t *testing.T) {
 			}
 
 			p := Provider{IngressClass: test.ingressClass}
-			conf := p.loadConfigurationFromCRD(context.Background(), newClientMock(test.paths...))
+			p.SetDefaults()
+
+			clientMock := newClientMock(test.paths...)
+			conf := p.loadConfigurationFromCRD(context.Background(), clientMock)
 			assert.Equal(t, test.expected, conf)
 		})
 	}
@@ -3519,7 +3656,10 @@ func TestLoadIngressRouteUDPs(t *testing.T) {
 			}
 
 			p := Provider{IngressClass: test.ingressClass}
-			conf := p.loadConfigurationFromCRD(context.Background(), newClientMock(test.paths...))
+			p.SetDefaults()
+
+			clientMock := newClientMock(test.paths...)
+			conf := p.loadConfigurationFromCRD(context.Background(), clientMock)
 			assert.Equal(t, test.expected, conf)
 		})
 	}
@@ -3738,3 +3878,572 @@ func TestGetServicePort(t *testing.T) {
 		})
 	}
 }
+
+func TestCrossNamespace(t *testing.T) {
+	testCases := []struct {
+		desc                string
+		allowCrossNamespace bool
+		ingressClass        string
+		paths               []string
+		expected            *dynamic.Configuration
+	}{
+		{
+			desc: "Empty",
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers:  map[string]*dynamic.UDPRouter{},
+					Services: map[string]*dynamic.UDPService{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers:  map[string]*dynamic.TCPRouter{},
+					Services: map[string]*dynamic.TCPService{},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers:           map[string]*dynamic.Router{},
+					Middlewares:       map[string]*dynamic.Middleware{},
+					Services:          map[string]*dynamic.Service{},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+		{
+			desc:  "HTTP middleware cross namespace disallowed",
+			paths: []string{"services.yml", "with_middleware_cross_namespace.yml"},
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers:  map[string]*dynamic.UDPRouter{},
+					Services: map[string]*dynamic.UDPService{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers:  map[string]*dynamic.TCPRouter{},
+					Services: map[string]*dynamic.TCPService{},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers: map[string]*dynamic.Router{
+						"default-test-crossnamespace-route-9313b71dbe6a649d5049": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test-crossnamespace-route-9313b71dbe6a649d5049",
+							Rule:        "Host(`foo.com`) && PathPrefix(`/bir`)",
+							Priority:    12,
+							Middlewares: []string{"default-test-errorpage"},
+						},
+					},
+					Middlewares: map[string]*dynamic.Middleware{
+						"cross-ns-stripprefix": {
+							StripPrefix: &dynamic.StripPrefix{
+								Prefixes:   []string{"/stripit"},
+								ForceSlash: false,
+							},
+						},
+					},
+					Services: map[string]*dynamic.Service{
+						"default-test-crossnamespace-route-9313b71dbe6a649d5049": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.1:80",
+									},
+									{
+										URL: "http://10.10.0.2:80",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+					},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+		{
+			desc:                "HTTP middleware cross namespace allowed",
+			paths:               []string{"services.yml", "with_middleware_cross_namespace.yml"},
+			allowCrossNamespace: true,
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers:  map[string]*dynamic.UDPRouter{},
+					Services: map[string]*dynamic.UDPService{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers:  map[string]*dynamic.TCPRouter{},
+					Services: map[string]*dynamic.TCPService{},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers: map[string]*dynamic.Router{
+						"default-test-crossnamespace-route-6b204d94623b3df4370c": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test-crossnamespace-route-6b204d94623b3df4370c",
+							Rule:        "Host(`foo.com`) && PathPrefix(`/bar`)",
+							Priority:    12,
+							Middlewares: []string{
+								"cross-ns-stripprefix",
+							},
+						},
+						"default-test-crossnamespace-route-9313b71dbe6a649d5049": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test-crossnamespace-route-9313b71dbe6a649d5049",
+							Rule:        "Host(`foo.com`) && PathPrefix(`/bir`)",
+							Priority:    12,
+							Middlewares: []string{"default-test-errorpage"},
+						},
+					},
+					Middlewares: map[string]*dynamic.Middleware{
+						"cross-ns-stripprefix": {
+							StripPrefix: &dynamic.StripPrefix{
+								Prefixes:   []string{"/stripit"},
+								ForceSlash: false,
+							},
+						},
+						"default-test-errorpage": {
+							Errors: &dynamic.ErrorPage{
+								Status:  []string{"500-599"},
+								Service: "default-test-errorpage-errorpage-service",
+								Query:   "/{status}.html",
+							},
+						},
+					},
+					Services: map[string]*dynamic.Service{
+						"default-test-crossnamespace-route-6b204d94623b3df4370c": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.1:80",
+									},
+									{
+										URL: "http://10.10.0.2:80",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+						"default-test-crossnamespace-route-9313b71dbe6a649d5049": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.1:80",
+									},
+									{
+										URL: "http://10.10.0.2:80",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+						"default-test-errorpage-errorpage-service": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.1:80",
+									},
+									{
+										URL: "http://10.10.0.2:80",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+					},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+		{
+			desc:                "HTTP cross namespace allowed",
+			paths:               []string{"services.yml", "with_cross_namespace.yml"},
+			allowCrossNamespace: true,
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers:  map[string]*dynamic.UDPRouter{},
+					Services: map[string]*dynamic.UDPService{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers:  map[string]*dynamic.TCPRouter{},
+					Services: map[string]*dynamic.TCPService{},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers: map[string]*dynamic.Router{
+						"default-cross-ns-route-6b204d94623b3df4370c": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-cross-ns-route-6b204d94623b3df4370c",
+							Rule:        "Host(`foo.com`) && PathPrefix(`/bar`)",
+							Priority:    12,
+						},
+					},
+					Middlewares: map[string]*dynamic.Middleware{},
+					Services: map[string]*dynamic.Service{
+						"default-cross-ns-route-6b204d94623b3df4370c": {
+							Weighted: &dynamic.WeightedRoundRobin{
+								Services: []dynamic.WRRService{
+									{
+										Name:   "cross-ns-whoami-svc-80",
+										Weight: func(i int) *int { return &i }(1),
+									},
+									{
+										Name:   "default-tr-svc-wrr1",
+										Weight: func(i int) *int { return &i }(1),
+									},
+									{
+										Name:   "cross-ns-tr-svc-wrr2",
+										Weight: func(i int) *int { return &i }(1),
+									},
+									{
+										Name:   "default-tr-svc-mirror1",
+										Weight: func(i int) *int { return &i }(1),
+									},
+									{
+										Name:   "cross-ns-tr-svc-mirror2",
+										Weight: func(i int) *int { return &i }(1),
+									},
+								},
+							},
+						},
+						"cross-ns-whoami-svc-80": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.1:80",
+									},
+									{
+										URL: "http://10.10.0.2:80",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+						"default-tr-svc-wrr1": {
+							Weighted: &dynamic.WeightedRoundRobin{
+								Services: []dynamic.WRRService{
+									{
+										Name:   "cross-ns-whoami-svc-80",
+										Weight: func(i int) *int { return &i }(1),
+									},
+								},
+							},
+						},
+						"cross-ns-tr-svc-wrr2": {
+							Weighted: &dynamic.WeightedRoundRobin{
+								Services: []dynamic.WRRService{
+									{
+										Name:   "cross-ns-whoami-svc-80",
+										Weight: func(i int) *int { return &i }(1),
+									},
+								},
+							},
+						},
+						"default-tr-svc-mirror1": {
+							Mirroring: &dynamic.Mirroring{
+								Service: "default-whoami-80",
+								Mirrors: []dynamic.MirrorService{
+									{
+										Name:    "cross-ns-whoami-svc-80",
+										Percent: 20,
+									},
+								},
+							},
+						},
+						"cross-ns-tr-svc-mirror2": {
+							Mirroring: &dynamic.Mirroring{
+								Service: "cross-ns-whoami-svc-80",
+								Mirrors: []dynamic.MirrorService{
+									{
+										Name:    "cross-ns-whoami-svc-80",
+										Percent: 20,
+									},
+								},
+							},
+						},
+						"default-whoami-80": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.1:80",
+									},
+									{
+										URL: "http://10.10.0.2:80",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+					},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+		{
+			desc:  "HTTP cross namespace disallowed",
+			paths: []string{"services.yml", "with_cross_namespace.yml"},
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers:  map[string]*dynamic.UDPRouter{},
+					Services: map[string]*dynamic.UDPService{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers:  map[string]*dynamic.TCPRouter{},
+					Services: map[string]*dynamic.TCPService{},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers:           map[string]*dynamic.Router{},
+					Middlewares:       map[string]*dynamic.Middleware{},
+					Services: map[string]*dynamic.Service{
+						"cross-ns-tr-svc-wrr2": {
+							Weighted: &dynamic.WeightedRoundRobin{
+								Services: []dynamic.WRRService{
+									{
+										Name:   "cross-ns-whoami-svc-80",
+										Weight: func(i int) *int { return &i }(1),
+									},
+								},
+							},
+						},
+						"cross-ns-whoami-svc-80": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.1:80",
+									},
+									{
+										URL: "http://10.10.0.2:80",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+						"cross-ns-tr-svc-mirror2": {
+							Mirroring: &dynamic.Mirroring{
+								Service: "cross-ns-whoami-svc-80",
+								Mirrors: []dynamic.MirrorService{
+									{
+										Name:    "cross-ns-whoami-svc-80",
+										Percent: 20,
+									},
+								},
+							},
+						},
+						"default-whoami-80": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.1:80",
+									},
+									{
+										URL: "http://10.10.0.2:80",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+					},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+		{
+			desc:                "TCP cross namespace allowed",
+			paths:               []string{"tcp/services.yml", "tcp/with_cross_namespace.yml"},
+			allowCrossNamespace: true,
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers:  map[string]*dynamic.UDPRouter{},
+					Services: map[string]*dynamic.UDPService{},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers:           map[string]*dynamic.Router{},
+					Middlewares:       map[string]*dynamic.Middleware{},
+					Services:          map[string]*dynamic.Service{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers: map[string]*dynamic.TCPRouter{
+						"default-test.route-fdd3e9338e47a45efefc": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test.route-fdd3e9338e47a45efefc",
+							Rule:        "HostSNI(`foo.com`)",
+						},
+					},
+					Services: map[string]*dynamic.TCPService{
+						"default-test.route-fdd3e9338e47a45efefc": {
+							LoadBalancer: &dynamic.TCPServersLoadBalancer{
+								Servers: []dynamic.TCPServer{
+									{
+										Address: "10.10.0.1:8000",
+										Port:    "",
+									},
+									{
+										Address: "10.10.0.2:8000",
+										Port:    "",
+									},
+								},
+							},
+						},
+					},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+		{
+			desc:  "TCP cross namespace disallowed",
+			paths: []string{"tcp/services.yml", "tcp/with_cross_namespace.yml"},
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers:  map[string]*dynamic.UDPRouter{},
+					Services: map[string]*dynamic.UDPService{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					// The router that references the invalid service will be discarded.
+					Routers: map[string]*dynamic.TCPRouter{
+						"default-test.route-fdd3e9338e47a45efefc": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test.route-fdd3e9338e47a45efefc",
+							Rule:        "HostSNI(`foo.com`)",
+						},
+					},
+					Services: map[string]*dynamic.TCPService{},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers:           map[string]*dynamic.Router{},
+					Middlewares:       map[string]*dynamic.Middleware{},
+					Services:          map[string]*dynamic.Service{},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+		{
+			desc:                "UDP cross namespace allowed",
+			paths:               []string{"udp/services.yml", "udp/with_cross_namespace.yml"},
+			allowCrossNamespace: true,
+			expected: &dynamic.Configuration{
+				UDP: &dynamic.UDPConfiguration{
+					Routers: map[string]*dynamic.UDPRouter{
+						"default-test.route-0": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test.route-0",
+						},
+					},
+					Services: map[string]*dynamic.UDPService{
+						"default-test.route-0": {
+							LoadBalancer: &dynamic.UDPServersLoadBalancer{
+								Servers: []dynamic.UDPServer{
+									{
+										Address: "10.10.0.1:8000",
+										Port:    "",
+									},
+									{
+										Address: "10.10.0.2:8000",
+										Port:    "",
+									},
+								},
+							},
+						},
+					},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers:           map[string]*dynamic.Router{},
+					Middlewares:       map[string]*dynamic.Middleware{},
+					Services:          map[string]*dynamic.Service{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers:  map[string]*dynamic.TCPRouter{},
+					Services: map[string]*dynamic.TCPService{},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+		{
+			desc:  "UDP cross namespace disallowed",
+			paths: []string{"udp/services.yml", "udp/with_cross_namespace.yml"},
+			expected: &dynamic.Configuration{
+				// The router that references the invalid service will be discarded.
+				UDP: &dynamic.UDPConfiguration{
+					Routers: map[string]*dynamic.UDPRouter{
+						"default-test.route-0": {
+							EntryPoints: []string{"foo"},
+							Service:     "default-test.route-0",
+						},
+					},
+					Services: map[string]*dynamic.UDPService{},
+				},
+				TCP: &dynamic.TCPConfiguration{
+					Routers:  map[string]*dynamic.TCPRouter{},
+					Services: map[string]*dynamic.TCPService{},
+				},
+				HTTP: &dynamic.HTTPConfiguration{
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+					Routers:           map[string]*dynamic.Router{},
+					Middlewares:       map[string]*dynamic.Middleware{},
+					Services:          map[string]*dynamic.Service{},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			var k8sObjects []runtime.Object
+			var crdObjects []runtime.Object
+			for _, path := range test.paths {
+				yamlContent, err := ioutil.ReadFile(filepath.FromSlash("./fixtures/" + path))
+				if err != nil {
+					panic(err)
+				}
+
+				objects := k8s.MustParseYaml(yamlContent)
+				for _, obj := range objects {
+					switch o := obj.(type) {
+					case *corev1.Service, *corev1.Endpoints, *corev1.Secret:
+						k8sObjects = append(k8sObjects, o)
+					case *v1alpha1.IngressRoute:
+						crdObjects = append(crdObjects, o)
+					case *v1alpha1.IngressRouteTCP:
+						crdObjects = append(crdObjects, o)
+					case *v1alpha1.IngressRouteUDP:
+						crdObjects = append(crdObjects, o)
+					case *v1alpha1.Middleware:
+						crdObjects = append(crdObjects, o)
+					case *v1alpha1.TraefikService:
+						crdObjects = append(crdObjects, o)
+					case *v1alpha1.TLSOption:
+						crdObjects = append(crdObjects, o)
+					case *v1alpha1.TLSStore:
+						crdObjects = append(crdObjects, o)
+					default:
+					}
+				}
+			}
+
+			kubeClient := kubefake.NewSimpleClientset(k8sObjects...)
+			crdClient := crdfake.NewSimpleClientset(crdObjects...)
+
+			client := newClientImpl(kubeClient, crdClient)
+
+			stopCh := make(chan struct{})
+
+			eventCh, err := client.WatchAll([]string{"default", "cross-ns"}, stopCh)
+			require.NoError(t, err)
+
+			if k8sObjects != nil || crdObjects != nil {
+				// just wait for the first event
+				<-eventCh
+			}
+
+			p := Provider{}
+			p.SetDefaults()
+
+			p.AllowCrossNamespace = func(b bool) *bool { return &b }(test.allowCrossNamespace)
+			conf := p.loadConfigurationFromCRD(context.Background(), client)
+			assert.Equal(t, test.expected, conf)
+		})
+	}
+}

pkg/provider/kubernetes/crd/kubernetes_udp.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net"
+	"strconv"
 
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
 	"github.com/traefik/traefik/v2/pkg/log"
@@ -34,7 +36,7 @@ func (p *Provider) loadIngressRouteUDPConfiguration(ctx context.Context, client
 			serviceName := makeID(ingressRouteUDP.Namespace, key)
 
 			for _, service := range route.Services {
-				balancerServerUDP, err := createLoadBalancerServerUDP(client, ingressRouteUDP.Namespace, service)
+				balancerServerUDP, err := p.createLoadBalancerServerUDP(client, ingressRouteUDP.Namespace, service)
 				if err != nil {
 					logger.
 						WithField("serviceName", service.Name).
@@ -75,9 +77,13 @@ func (p *Provider) loadIngressRouteUDPConfiguration(ctx context.Context, client
 	return conf
 }
 
-func createLoadBalancerServerUDP(client Client, namespace string, service v1alpha1.ServiceUDP) (*dynamic.UDPService, error) {
-	ns := namespace
+func (p *Provider) createLoadBalancerServerUDP(client Client, parentNamespace string, service v1alpha1.ServiceUDP) (*dynamic.UDPService, error) {
+	ns := parentNamespace
 	if len(service.Namespace) > 0 {
+		if !isNamespaceAllowed(p.AllowCrossNamespace, parentNamespace, service.Namespace) {
+			return nil, fmt.Errorf("udp service %s/%s is not in the parent resource namespace %s", service.Namespace, service.Name, ns)
+		}
+
 		ns = service.Namespace
 	}
 
@@ -121,7 +127,7 @@ func loadUDPServers(client Client, namespace string, svc v1alpha1.ServiceUDP) ([
 	var servers []dynamic.UDPServer
 	if service.Spec.Type == corev1.ServiceTypeExternalName {
 		servers = append(servers, dynamic.UDPServer{
-			Address: fmt.Sprintf("%s:%d", service.Spec.ExternalName, portSpec.Port),
+			Address: net.JoinHostPort(service.Spec.ExternalName, strconv.Itoa(int(portSpec.Port))),
 		})
 	} else {
 		endpoints, endpointsExists, endpointsErr := client.GetEndpoints(namespace, svc.Name)
@@ -152,7 +158,7 @@ func loadUDPServers(client Client, namespace string, svc v1alpha1.ServiceUDP) ([
 
 			for _, addr := range subset.Addresses {
 				servers = append(servers, dynamic.UDPServer{
-					Address: fmt.Sprintf("%s:%d", addr.IP, port),
+					Address: net.JoinHostPort(addr.IP, strconv.Itoa(int(port))),
 				})
 			}
 		}

pkg/provider/kubernetes/ingress/fixtures/Ingress-with-IPv6-endpoints_endpoint.yml

@@ -0,0 +1,12 @@
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: service-bar
+  namespace: testing
+
+subsets:
+- addresses:
+  - ip: "2001:0db8:3c4d:0015:0000:0000:1a2f:1a2b"
+  ports:
+  - name: http
+    port: 8080

pkg/provider/kubernetes/ingress/fixtures/Ingress-with-IPv6-endpoints_ingress.yml

@@ -0,0 +1,18 @@
+kind: Ingress
+apiVersion: networking.k8s.io/v1beta1
+metadata:
+  name: example.com
+  namespace: testing
+
+spec:
+  rules:
+    - http:
+        paths:
+          - path: /bar
+            backend:
+              serviceName: service-bar
+              servicePort: 8080
+          - path: /foo
+            backend:
+              serviceName: service-foo
+              servicePort: 8080

pkg/provider/kubernetes/ingress/fixtures/Ingress-with-IPv6-endpoints_service.yml

@@ -0,0 +1,26 @@
+kind: Service
+apiVersion: v1
+metadata:
+  name: service-bar
+  namespace: testing
+
+spec:
+  ports:
+  - name: http
+    port: 8080
+  clusterIp: "fc00:f853:ccd:e793::1"
+  type: ClusterIP
+
+---
+kind: Service
+apiVersion: v1
+metadata:
+  name: service-foo
+  namespace: testing
+
+spec:
+  ports:
+  - name: http
+    port: 8080
+  type: ExternalName
+  externalName: "2001:0db8:3c4d:0015:0000:0000:1a2f:2a3b"

pkg/provider/kubernetes/ingress/kubernetes.go

@@ -5,8 +5,10 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"net"
 	"os"
 	"sort"
+	"strconv"
 	"strings"
 	"time"
 
@@ -479,9 +481,10 @@ func loadService(client Client, namespace string, backend networkingv1beta1.Ingr
 
 	if service.Spec.Type == corev1.ServiceTypeExternalName {
 		protocol := getProtocol(portSpec, portSpec.Name, svcConfig)
+		hostPort := net.JoinHostPort(service.Spec.ExternalName, strconv.Itoa(int(portSpec.Port)))
 
 		svc.LoadBalancer.Servers = []dynamic.Server{
-			{URL: fmt.Sprintf("%s://%s:%d", protocol, service.Spec.ExternalName, portSpec.Port)},
+			{URL: fmt.Sprintf("%s://%s", protocol, hostPort)},
 		}
 
 		return svc, nil
@@ -516,8 +519,10 @@ func loadService(client Client, namespace string, backend networkingv1beta1.Ingr
 		protocol := getProtocol(portSpec, portName, svcConfig)
 
 		for _, addr := range subset.Addresses {
+			hostPort := net.JoinHostPort(addr.IP, strconv.Itoa(int(port)))
+
 			svc.LoadBalancer.Servers = append(svc.LoadBalancer.Servers, dynamic.Server{
-				URL: fmt.Sprintf("%s://%s:%d", protocol, addr.IP, port),
+				URL: fmt.Sprintf("%s://%s", protocol, hostPort),
 			})
 		}
 	}

pkg/provider/kubernetes/ingress/kubernetes_test.go

@@ -661,6 +661,47 @@ func TestLoadConfigurationFromIngresses(t *testing.T) {
 				},
 			},
 		},
+		{
+			desc: "Ingress with IPv6 endpoints",
+			expected: &dynamic.Configuration{
+				TCP: &dynamic.TCPConfiguration{},
+				HTTP: &dynamic.HTTPConfiguration{
+					Middlewares: map[string]*dynamic.Middleware{},
+					Routers: map[string]*dynamic.Router{
+						"example-com-testing-bar": {
+							Rule:    "PathPrefix(`/bar`)",
+							Service: "testing-service-bar-8080",
+						},
+						"example-com-testing-foo": {
+							Rule:    "PathPrefix(`/foo`)",
+							Service: "testing-service-foo-8080",
+						},
+					},
+					Services: map[string]*dynamic.Service{
+						"testing-service-bar-8080": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://[2001:0db8:3c4d:0015:0000:0000:1a2f:1a2b]:8080",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+						"testing-service-foo-8080": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://[2001:0db8:3c4d:0015:0000:0000:1a2f:2a3b]:8080",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+					},
+				},
+			},
+		},
 		{
 			desc: "TLS support",
 			expected: &dynamic.Configuration{

pkg/server/router/tcp/router.go

@@ -109,13 +109,18 @@ func (m *Manager) buildEntryPointHandler(ctx context.Context, configs map[string
 	tlsOptionsForHostSNI := map[string]map[string]nameAndConfig{}
 	tlsOptionsForHost := map[string]string{}
 	for routerHTTPName, routerHTTPConfig := range configsHTTP {
-		if len(routerHTTPConfig.TLS.Options) == 0 || routerHTTPConfig.TLS.Options == defaultTLSConfigName {
+		if routerHTTPConfig.TLS == nil {
 			continue
 		}
 
 		ctxRouter := log.With(provider.AddInContext(ctx, routerHTTPName), log.Str(log.RouterName, routerHTTPName))
 		logger := log.FromContext(ctxRouter)
 
+		tlsOptionsName := defaultTLSConfigName
+		if len(routerHTTPConfig.TLS.Options) > 0 && routerHTTPConfig.TLS.Options != defaultTLSConfigName {
+			tlsOptionsName = provider.GetQualifiedName(ctxRouter, routerHTTPConfig.TLS.Options)
+		}
+
 		domains, err := rules.ParseDomains(routerHTTPConfig.Rule)
 		if err != nil {
 			routerErr := fmt.Errorf("invalid rule %s, error: %w", routerHTTPConfig.Rule, err)
@@ -129,34 +134,27 @@ func (m *Manager) buildEntryPointHandler(ctx context.Context, configs map[string
 		}
 
 		for _, domain := range domains {
-			if routerHTTPConfig.TLS != nil {
-				tlsOptionsName := routerHTTPConfig.TLS.Options
-				if tlsOptionsName != defaultTLSConfigName {
-					tlsOptionsName = provider.GetQualifiedName(ctxRouter, routerHTTPConfig.TLS.Options)
-				}
+			tlsConf, err := m.tlsManager.Get(defaultTLSStoreName, tlsOptionsName)
+			if err != nil {
+				routerHTTPConfig.AddError(err, true)
+				logger.Debug(err)
+				continue
+			}
 
-				tlsConf, err := m.tlsManager.Get(defaultTLSStoreName, tlsOptionsName)
-				if err != nil {
-					routerHTTPConfig.AddError(err, true)
-					logger.Debug(err)
-					continue
-				}
+			// domain is already in lower case thanks to the domain parsing
+			if tlsOptionsForHostSNI[domain] == nil {
+				tlsOptionsForHostSNI[domain] = make(map[string]nameAndConfig)
+			}
+			tlsOptionsForHostSNI[domain][tlsOptionsName] = nameAndConfig{
+				routerName: routerHTTPName,
+				TLSConfig:  tlsConf,
+			}
 
-				// domain is already in lower case thanks to the domain parsing
-				if tlsOptionsForHostSNI[domain] == nil {
-					tlsOptionsForHostSNI[domain] = make(map[string]nameAndConfig)
-				}
-				tlsOptionsForHostSNI[domain][routerHTTPConfig.TLS.Options] = nameAndConfig{
-					routerName: routerHTTPName,
-					TLSConfig:  tlsConf,
-				}
-
-				if _, ok := tlsOptionsForHost[domain]; ok {
-					// Multiple tlsOptions fallback to default
-					tlsOptionsForHost[domain] = "default"
-				} else {
-					tlsOptionsForHost[domain] = routerHTTPConfig.TLS.Options
-				}
+			if name, ok := tlsOptionsForHost[domain]; ok && name != tlsOptionsName {
+				// Different tlsOptions on the same domain fallback to default
+				tlsOptionsForHost[domain] = defaultTLSConfigName
+			} else {
+				tlsOptionsForHost[domain] = tlsOptionsName
 			}
 		}
 	}
@@ -304,5 +302,5 @@ func findTLSOptionName(tlsOptionsForHost map[string]string, host string) string
 		return tlsOptions
 	}
 
-	return "default"
+	return defaultTLSConfigName
 }

pkg/server/router/tcp/router_test.go

@@ -2,25 +2,31 @@ package tcp
 
 import (
 	"context"
+	"crypto/tls"
+	"net/http"
+	"net/http/httptest"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
 	"github.com/traefik/traefik/v2/pkg/config/runtime"
 	"github.com/traefik/traefik/v2/pkg/server/service/tcp"
-	"github.com/traefik/traefik/v2/pkg/tls"
+	traefiktls "github.com/traefik/traefik/v2/pkg/tls"
 )
 
 func TestRuntimeConfiguration(t *testing.T) {
 	testCases := []struct {
-		desc          string
-		serviceConfig map[string]*runtime.TCPServiceInfo
-		routerConfig  map[string]*runtime.TCPRouterInfo
-		expectedError int
+		desc              string
+		httpServiceConfig map[string]*runtime.ServiceInfo
+		httpRouterConfig  map[string]*runtime.RouterInfo
+		tcpServiceConfig  map[string]*runtime.TCPServiceInfo
+		tcpRouterConfig   map[string]*runtime.TCPRouterInfo
+		expectedError     int
 	}{
 		{
 			desc: "No error",
-			serviceConfig: map[string]*runtime.TCPServiceInfo{
+			tcpServiceConfig: map[string]*runtime.TCPServiceInfo{
 				"foo-service": {
 					TCPService: &dynamic.TCPService{
 						LoadBalancer: &dynamic.TCPServersLoadBalancer{
@@ -38,7 +44,7 @@ func TestRuntimeConfiguration(t *testing.T) {
 					},
 				},
 			},
-			routerConfig: map[string]*runtime.TCPRouterInfo{
+			tcpRouterConfig: map[string]*runtime.TCPRouterInfo{
 				"foo": {
 					TCPRouter: &dynamic.TCPRouter{
 						EntryPoints: []string{"web"},
@@ -65,9 +71,54 @@ func TestRuntimeConfiguration(t *testing.T) {
 			},
 			expectedError: 0,
 		},
+		{
+			desc: "HTTP routers with same domain but different TLS options",
+			httpServiceConfig: map[string]*runtime.ServiceInfo{
+				"foo-service": {
+					Service: &dynamic.Service{
+						LoadBalancer: &dynamic.ServersLoadBalancer{
+							Servers: []dynamic.Server{
+								{
+									Port: "8085",
+									URL:  "127.0.0.1:8085",
+								},
+								{
+									URL:  "127.0.0.1:8086",
+									Port: "8086",
+								},
+							},
+						},
+					},
+				},
+			},
+			httpRouterConfig: map[string]*runtime.RouterInfo{
+				"foo": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Service:     "foo-service",
+						Rule:        "Host(`bar.foo`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "foo",
+						},
+					},
+				},
+				"bar": {
+					Router: &dynamic.Router{
+
+						EntryPoints: []string{"web"},
+						Service:     "foo-service",
+						Rule:        "Host(`bar.foo`) && PathPrefix(`/path`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "bar",
+						},
+					},
+				},
+			},
+			expectedError: 2,
+		},
 		{
 			desc: "One router with wrong rule",
-			serviceConfig: map[string]*runtime.TCPServiceInfo{
+			tcpServiceConfig: map[string]*runtime.TCPServiceInfo{
 				"foo-service": {
 					TCPService: &dynamic.TCPService{
 						LoadBalancer: &dynamic.TCPServersLoadBalancer{
@@ -80,7 +131,7 @@ func TestRuntimeConfiguration(t *testing.T) {
 					},
 				},
 			},
-			routerConfig: map[string]*runtime.TCPRouterInfo{
+			tcpRouterConfig: map[string]*runtime.TCPRouterInfo{
 				"foo": {
 					TCPRouter: &dynamic.TCPRouter{
 						EntryPoints: []string{"web"},
@@ -101,7 +152,7 @@ func TestRuntimeConfiguration(t *testing.T) {
 		},
 		{
 			desc: "All router with wrong rule",
-			serviceConfig: map[string]*runtime.TCPServiceInfo{
+			tcpServiceConfig: map[string]*runtime.TCPServiceInfo{
 				"foo-service": {
 					TCPService: &dynamic.TCPService{
 						LoadBalancer: &dynamic.TCPServersLoadBalancer{
@@ -114,7 +165,7 @@ func TestRuntimeConfiguration(t *testing.T) {
 					},
 				},
 			},
-			routerConfig: map[string]*runtime.TCPRouterInfo{
+			tcpRouterConfig: map[string]*runtime.TCPRouterInfo{
 				"foo": {
 					TCPRouter: &dynamic.TCPRouter{
 						EntryPoints: []string{"web"},
@@ -134,7 +185,7 @@ func TestRuntimeConfiguration(t *testing.T) {
 		},
 		{
 			desc: "Router with unknown service",
-			serviceConfig: map[string]*runtime.TCPServiceInfo{
+			tcpServiceConfig: map[string]*runtime.TCPServiceInfo{
 				"foo-service": {
 					TCPService: &dynamic.TCPService{
 						LoadBalancer: &dynamic.TCPServersLoadBalancer{
@@ -147,7 +198,7 @@ func TestRuntimeConfiguration(t *testing.T) {
 					},
 				},
 			},
-			routerConfig: map[string]*runtime.TCPRouterInfo{
+			tcpRouterConfig: map[string]*runtime.TCPRouterInfo{
 				"foo": {
 					TCPRouter: &dynamic.TCPRouter{
 						EntryPoints: []string{"web"},
@@ -168,14 +219,14 @@ func TestRuntimeConfiguration(t *testing.T) {
 		},
 		{
 			desc: "Router with broken service",
-			serviceConfig: map[string]*runtime.TCPServiceInfo{
+			tcpServiceConfig: map[string]*runtime.TCPServiceInfo{
 				"foo-service": {
 					TCPService: &dynamic.TCPService{
 						LoadBalancer: nil,
 					},
 				},
 			},
-			routerConfig: map[string]*runtime.TCPRouterInfo{
+			tcpRouterConfig: map[string]*runtime.TCPRouterInfo{
 				"bar": {
 					TCPRouter: &dynamic.TCPRouter{
 						EntryPoints: []string{"web"},
@@ -197,15 +248,17 @@ func TestRuntimeConfiguration(t *testing.T) {
 			entryPoints := []string{"web"}
 
 			conf := &runtime.Configuration{
-				TCPServices: test.serviceConfig,
-				TCPRouters:  test.routerConfig,
+				Services:    test.httpServiceConfig,
+				Routers:     test.httpRouterConfig,
+				TCPServices: test.tcpServiceConfig,
+				TCPRouters:  test.tcpRouterConfig,
 			}
 			serviceManager := tcp.NewManager(conf)
-			tlsManager := tls.NewManager()
+			tlsManager := traefiktls.NewManager()
 			tlsManager.UpdateConfigs(
 				context.Background(),
-				map[string]tls.Store{},
-				map[string]tls.Options{
+				map[string]traefiktls.Store{},
+				map[string]traefiktls.Options{
 					"default": {
 						MinVersion: "VersionTLS10",
 					},
@@ -216,7 +269,7 @@ func TestRuntimeConfiguration(t *testing.T) {
 						MinVersion: "VersionTLS11",
 					},
 				},
-				[]*tls.CertAndStores{})
+				[]*traefiktls.CertAndStores{})
 
 			routerManager := NewManager(conf, serviceManager,
 				nil, nil, tlsManager)
@@ -237,7 +290,235 @@ func TestRuntimeConfiguration(t *testing.T) {
 					allErrors++
 				}
 			}
+			for _, v := range conf.Services {
+				if v.Err != nil {
+					allErrors++
+				}
+			}
+			for _, v := range conf.Routers {
+				if len(v.Err) > 0 {
+					allErrors++
+				}
+			}
 			assert.Equal(t, test.expectedError, allErrors)
 		})
 	}
 }
+
+func TestDomainFronting(t *testing.T) {
+	tests := []struct {
+		desc           string
+		routers        map[string]*runtime.RouterInfo
+		expectedStatus int
+	}{
+		{
+			desc: "Request is misdirected when TLS options are different",
+			routers: map[string]*runtime.RouterInfo{
+				"router-1@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host1.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+				"router-2@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host2.local`)",
+						TLS:         &dynamic.RouterTLSConfig{},
+					},
+				},
+			},
+			expectedStatus: http.StatusMisdirectedRequest,
+		},
+		{
+			desc: "Request is OK when TLS options are the same",
+			routers: map[string]*runtime.RouterInfo{
+				"router-1@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host1.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+				"router-2@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host2.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+			},
+			expectedStatus: http.StatusOK,
+		},
+		{
+			desc: "Default TLS options is used when options are ambiguous for the same host",
+			routers: map[string]*runtime.RouterInfo{
+				"router-1@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host1.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+				"router-2@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host1.local`) && PathPrefix(`/foo`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "default",
+						},
+					},
+				},
+				"router-3@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host2.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+			},
+			expectedStatus: http.StatusMisdirectedRequest,
+		},
+		{
+			desc: "Default TLS options should not be used when options are the same for the same host",
+			routers: map[string]*runtime.RouterInfo{
+				"router-1@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host1.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+				"router-2@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host1.local`) && PathPrefix(`/bar`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+				"router-3@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host2.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+			},
+			expectedStatus: http.StatusOK,
+		},
+		{
+			desc: "Request is misdirected when TLS options have the same name but from different providers",
+			routers: map[string]*runtime.RouterInfo{
+				"router-1@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host1.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+				"router-2@crd": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host2.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1",
+						},
+					},
+				},
+			},
+			expectedStatus: http.StatusMisdirectedRequest,
+		},
+		{
+			desc: "Request is OK when TLS options reference from a different provider is the same",
+			routers: map[string]*runtime.RouterInfo{
+				"router-1@file": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host1.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1@crd",
+						},
+					},
+				},
+				"router-2@crd": {
+					Router: &dynamic.Router{
+						EntryPoints: []string{"web"},
+						Rule:        "Host(`host2.local`)",
+						TLS: &dynamic.RouterTLSConfig{
+							Options: "host1@crd",
+						},
+					},
+				},
+			},
+			expectedStatus: http.StatusOK,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.desc, func(t *testing.T) {
+			entryPoints := []string{"web"}
+			tlsOptions := map[string]traefiktls.Options{
+				"default": {
+					MinVersion: "VersionTLS10",
+				},
+				"host1@file": {
+					MinVersion: "VersionTLS12",
+				},
+				"host1@crd": {
+					MinVersion: "VersionTLS12",
+				},
+			}
+
+			conf := &runtime.Configuration{
+				Routers: test.routers,
+			}
+
+			serviceManager := tcp.NewManager(conf)
+
+			tlsManager := traefiktls.NewManager()
+			tlsManager.UpdateConfigs(context.Background(), map[string]traefiktls.Store{}, tlsOptions, []*traefiktls.CertAndStores{})
+
+			httpsHandler := map[string]http.Handler{
+				"web": http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {}),
+			}
+
+			routerManager := NewManager(conf, serviceManager, nil, httpsHandler, tlsManager)
+
+			routers := routerManager.BuildHandlers(context.Background(), entryPoints)
+
+			router, ok := routers["web"]
+			require.True(t, ok)
+
+			req := httptest.NewRequest(http.MethodGet, "/", nil)
+			req.Host = "host1.local"
+			req.TLS = &tls.ConnectionState{
+				ServerName: "host2.local",
+			}
+
+			rw := httptest.NewRecorder()
+
+			router.GetHTTPSHandler().ServeHTTP(rw, req)
+
+			assert.Equal(t, test.expectedStatus, rw.Code)
+		})
+	}
+}