Disable ExternalName type of Service exporting

ExternalName type of Service shouldn't be exported since it has no
ClusterIP assinged, and it's not supported by KEP1645 either. So add
a few validation codes to disable ExternalName type of Service
exporting.

Signed-off-by: Lan Luo <luola@vmware.com>

multicluster/controllers/multicluster/member/serviceexport_controller.go

@@ -79,6 +79,7 @@ type reason int
 
 const (
 	serviceNotFound reason = iota
+	serviceNotSupported
 	isImportedService
 	serviceWithoutEndpoints
 	serviceExported
@@ -199,6 +200,16 @@ func (r *ServiceExportReconciler) Reconcile(ctx context.Context, req ctrl.Reques
 		return ctrl.Result{}, err
 	}
 
+	// The ExternalName type of Service is not supported since it has no ClusterIP
+	// assgined to the Service.
+	if svc.Spec.Type == corev1.ServiceTypeExternalName {
+		err = r.updateSvcExportStatus(ctx, req, serviceNotSupported)
+		if err != nil {
+			return ctrl.Result{}, err
+		}
+		return ctrl.Result{}, nil
+	}
+
 	// Skip if ServiceExport is trying to export a multi-cluster Service.
 	if !svcInstalled {
 		if _, ok := svc.Annotations[common.AntreaMCServiceAnnotation]; ok {
@@ -402,6 +413,9 @@ func (r *ServiceExportReconciler) updateSvcExportStatus(ctx context.Context, req
 	case serviceNotFound:
 		newCondition.Reason = getStringPointer("service_not_found")
 		newCondition.Message = getStringPointer("the Service does not exist")
+	case serviceNotSupported:
+		newCondition.Reason = getStringPointer("service_type_not_supported")
+		newCondition.Message = getStringPointer("the ExternalName type of Service is not supported")
 	case serviceWithoutEndpoints:
 		newCondition.Reason = getStringPointer("service_without_endpoints")
 		newCondition.Message = getStringPointer("the Service has no Endpoints, failed to export")

multicluster/controllers/multicluster/member/serviceexport_controller_test.go

@@ -178,16 +178,37 @@ func TestServiceExportReconciler_CheckExportStatus(t *testing.T) {
 	nginx2SvcExportWithStatus.Name = "nginx2"
 	existingMessage := "the Service has no related Endpoints"
 	nginx2SvcExportWithStatus.Status.Conditions[0].Message = &existingMessage
+
+	nginx3Svc := common.SvcNginx.DeepCopy()
+	nginx3Svc.Name = "nginx3"
+	nginx3Svc.Spec.Type = corev1.ServiceTypeExternalName
+	nginx3SvcExport := &k8smcsv1alpha1.ServiceExport{
+		ObjectMeta: metav1.ObjectMeta{
+			Namespace: "default",
+			Name:      "nginx3",
+		},
+	}
+
 	tests := []struct {
 		name            string
 		expectedReason  string
 		expectedMessage string
 		req             ctrl.Request
 	}{
 		{
-			name:           "export non-existing Service",
-			expectedReason: "service_not_found",
-			req:            nginxReq,
+			name:            "export non-existing Service",
+			expectedReason:  "service_not_found",
+			expectedMessage: "the Service does not exist",
+			req:             nginxReq,
+		},
+		{
+			name:            "export ExternalName type of Service",
+			expectedReason:  "service_type_not_supported",
+			expectedMessage: "the ExternalName type of Service is not supported",
+			req: ctrl.Request{NamespacedName: types.NamespacedName{
+				Namespace: "default",
+				Name:      "nginx3",
+			}},
 		},
 		{
 			name:           "export multi-cluster Service",
@@ -224,8 +245,8 @@ func TestServiceExportReconciler_CheckExportStatus(t *testing.T) {
 		},
 	}
 
-	fakeClient := fake.NewClientBuilder().WithScheme(common.TestScheme).WithObjects(mcsSvc, nginx0Svc, nginx1Svc, nginx1EP, nginx2Svc, existSvcExport,
-		nginx0SvcExport, nginx1SvcExportWithStatus, nginx2SvcExportWithStatus, mcsSvcExport).Build()
+	fakeClient := fake.NewClientBuilder().WithScheme(common.TestScheme).WithObjects(mcsSvc, nginx0Svc, nginx1Svc, nginx3Svc, nginx1EP, nginx2Svc, existSvcExport,
+		nginx0SvcExport, nginx1SvcExportWithStatus, nginx2SvcExportWithStatus, nginx3SvcExport, mcsSvcExport).Build()
 	fakeRemoteClient := fake.NewClientBuilder().WithScheme(common.TestScheme).Build()
 	commonArea := commonarea.NewFakeRemoteCommonArea(fakeRemoteClient, "leader-cluster", common.LocalClusterID, "default", nil)