Fix concatenation of IPv6 addresses and ports

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{