Fix multiple subsets endpoint

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

@@ -0,0 +1,54 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoami-svc-multiple-subsets
+  namespace: default
+
+spec:
+  ports:
+    - name: web
+      port: 80
+    - name: web2
+      port: 8080
+  selector:
+    app: traefiklabs
+    task: whoami
+
+---
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: whoami-svc-multiple-subsets
+  namespace: default
+
+subsets:
+  - addresses:
+      - ip: 10.10.0.1
+      - ip: 10.10.0.2
+    ports:
+      - name: web
+        port: 80
+  - addresses:
+      - ip: 10.10.0.3
+      - ip: 10.10.0.4
+    ports:
+      - name: web2
+        port: 8080
+---
+apiVersion: traefik.io/v1alpha1
+kind: IngressRoute
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+    - match: Host(`foo.com`) && PathPrefix(`/bar`)
+      kind: Rule
+      priority: 12
+      services:
+        - name: whoami-svc-multiple-subsets
+          port: 8080

pkg/provider/kubernetes/crd/kubernetes_http.go

@@ -414,8 +414,8 @@ func (c configBuilder) loadServers(parentNamespace string, svc traefikv1alpha1.L
 		return nil, fmt.Errorf("subset not found for %s/%s", namespace, sanitizedName)
 	}
 
-	var port int32
 	for _, subset := range endpoints.Subsets {
+		var port int32
 		for _, p := range subset.Ports {
 			if svcPort.Name == p.Name {
 				port = p.Port
@@ -424,7 +424,7 @@ func (c configBuilder) loadServers(parentNamespace string, svc traefikv1alpha1.L
 		}
 
 		if port == 0 {
-			return nil, fmt.Errorf("cannot define a port for %s/%s", namespace, sanitizedName)
+			continue
 		}
 
 		protocol, err := parseServiceProtocol(svc.Scheme, svcPort.Name, svcPort.Port)

pkg/provider/kubernetes/crd/kubernetes_test.go

@@ -4037,6 +4037,50 @@ func TestLoadIngressRoutes(t *testing.T) {
 				TLS: &dynamic.TLSConfiguration{},
 			},
 		},
+		{
+			desc:               "IngressRoute, service with multiple subsets",
+			allowEmptyServices: true,
+			paths:              []string{"services.yml", "with_multiple_subsets.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{},
+					Middlewares: map[string]*dynamic.TCPMiddleware{},
+					Services:    map[string]*dynamic.TCPService{},
+				},
+				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`)",
+							Priority:    12,
+						},
+					},
+					Middlewares: map[string]*dynamic.Middleware{},
+					Services: map[string]*dynamic.Service{
+						"default-test-route-6b204d94623b3df4370c": {
+							LoadBalancer: &dynamic.ServersLoadBalancer{
+								Servers: []dynamic.Server{
+									{
+										URL: "http://10.10.0.3:8080",
+									},
+									{
+										URL: "http://10.10.0.4:8080",
+									},
+								},
+								PassHostHeader: Bool(true),
+							},
+						},
+					},
+					ServersTransports: map[string]*dynamic.ServersTransport{},
+				},
+				TLS: &dynamic.TLSConfiguration{},
+			},
+		},
 		{
 			desc:               "TraefikService, empty service allowed",
 			allowEmptyServices: true,