Allow empty services in Kubernetes CRD

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

@@ -197,3 +197,26 @@ subsets:
     ports:
       - name: myapp
         port: 8000
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: whoamiudp-without-endpoints-subsets
+  namespace: default
+
+spec:
+  ports:
+    - name: myapp
+      port: 8000
+
+  selector:
+    app: traefiklabs
+    task: whoamiudp
+
+---
+kind: Endpoints
+apiVersion: v1
+metadata:
+  name: whoamiudp-without-endpoints-subsets
+  namespace: default

pkg/provider/kubernetes/crd/fixtures/udp/with_empty_services.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-without-endpoints-subsets
+          port: 8000