Allow publishing services with type ExternalName

pkg/provider/kubernetes/ingress/fixtures/Published-Service-ExternalName.yml

@@ -0,0 +1,83 @@
+---
+kind: Node
+apiVersion: v1
+metadata:
+  name: node1
+
+status:
+  addresses:
+    - type: ExternalIP
+      address: 1.2.3.4
+
+---
+kind: Node
+apiVersion: v1
+metadata:
+  name: node2
+
+status:
+  addresses:
+    - type: ExternalIP
+      address: 5.6.7.8
+
+---
+kind: Service
+apiVersion: v1
+metadata:
+  name: published-service
+  namespace: default
+
+spec:
+  type: ExternalName
+  externalName: example.com
+
+---
+kind: Ingress
+apiVersion: networking.k8s.io/v1
+metadata:
+  name: foo
+  namespace: default
+
+spec:
+  rules:
+  - host: "*.foo.com"
+    http:
+      paths:
+      - path: /
+        pathType: Prefix
+        backend:
+          service:
+            name: service1
+            port:
+              number: 80
+
+---
+kind: Service
+apiVersion: v1
+metadata:
+  name: service1
+  namespace: default
+
+spec:
+  ports:
+    - port: 80
+
+  clusterIP: 10.0.0.1
+
+---
+kind: EndpointSlice
+apiVersion: discovery.k8s.io/v1
+metadata:
+  name: service1-abc
+  labels:
+    kubernetes.io/service-name: service1
+
+addressType: IPv4
+ports:
+  - port: 8080
+    name: ""
+endpoints:
+  - addresses:
+      - 10.10.0.1
+    conditions:
+      ready: true

pkg/provider/kubernetes/ingress/kubernetes.go

@@ -484,6 +484,11 @@ func (p *Provider) updateIngressStatus(ing *netv1.Ingress, k8sClient Client) err
 			}
 		}
 
+	case corev1.ServiceTypeExternalName:
+		ingressStatus = []netv1.IngressLoadBalancerIngress{{
+			Hostname: service.Spec.ExternalName,
+		}}
+
 	default:
 		return fmt.Errorf("unsupported service type: %s", service.Spec.Type)
 	}

pkg/provider/kubernetes/ingress/kubernetes_test.go

@@ -2298,6 +2298,14 @@ func TestIngressEndpointPublishedService(t *testing.T) {
 				},
 			},
 		},
+		{
+			desc: "Published Service ExternalName",
+			expected: []netv1.IngressLoadBalancerIngress{
+				{
+					Hostname: "example.com",
+				},
+			},
+		},
 	}
 
 	for _, test := range testCases {