Improve kubernetes external name service support

Co-authored-by: jbdoumenjou <jb.doumenjou@gmail.com>

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

@@ -131,3 +131,40 @@ subsets:
     ports:
       - name: myapp4
         port: 8084
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: external-svc
+  namespace: default
+spec:
+  externalName: external.domain
+  type: ExternalName
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: external.service.with.port
+  namespace: default
+spec:
+  externalName: external.domain
+  type: ExternalName
+  ports:
+    - name: http
+      protocol: TCP
+      port: 80
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: external.service.without.port
+  namespace: default
+spec:
+  externalName: external.domain
+  type: ExternalName
+  ports:
+    - name: http
+      protocol: TCP

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

@@ -0,0 +1,15 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRouteTCP
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - match: HostSNI(`foo.com`)
+    services:
+    - name: external-svc
+      port: 8000

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

@@ -0,0 +1,15 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRouteTCP
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - match: HostSNI(`foo.com`)
+    services:
+    - name: external.service.with.port
+      port: 80

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

@@ -0,0 +1,14 @@
+apiVersion: traefik.containo.us/v1alpha1
+kind: IngressRouteTCP
+metadata:
+  name: test.route
+  namespace: default
+
+spec:
+  entryPoints:
+    - foo
+
+  routes:
+  - match: HostSNI(`foo.com`)
+    services:
+    - name: external-svc