Fix concatenation of IPv6 addresses and ports

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 +186,16 @@ 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

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 +197,14 @@ 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

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 +101,32 @@ 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

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_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/kubernetes_http.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net"
+	"strconv"
 	"strings"
 
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
@@ -301,8 +303,10 @@ 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
 	}
 
@@ -336,8 +340,10 @@ 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),
 			})
 		}
 	}

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"
@@ -165,7 +167,7 @@ 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)
@@ -196,7 +198,7 @@ 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

@@ -987,6 +987,128 @@ 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{
+					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 {

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"
@@ -121,7 +123,7 @@ 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 +154,7 @@ 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{