Improve kubernetes external name service support

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

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

@@ -118,3 +118,44 @@ subsets:
     ports:
       - name: websecure2
         port: 8443
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: external-svc
+  namespace: default
+spec:
+  externalName: external.domain
+  type: ExternalName
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: external-svc-with-http
+  namespace: default
+spec:
+  externalName: external.domain
+  type: ExternalName
+  ports:
+    - name: http
+      protocol: TCP
+      port: 80
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: external-svc-with-https
+  namespace: default
+spec:
+  externalName: external.domain
+  type: ExternalName
+  ports:
+    - name: https
+      protocol: TCP
+      port: 443
+
+
+