fix: use informer for istio gateways

Signed-off-by: Lukas Wöhrl <lukas.woehrl@plentymarkets.com>

source/istio_virtualservice.go

@@ -55,6 +55,7 @@ type virtualServiceSource struct {
 	ignoreHostnameAnnotation bool
 	serviceInformer          coreinformers.ServiceInformer
 	virtualserviceInformer   networkingv1alpha3informer.VirtualServiceInformer
+	gatewayInformer          networkingv1alpha3informer.GatewayInformer
 }
 
 // NewIstioVirtualServiceSource creates a new virtualServiceSource with the given config.
@@ -79,6 +80,7 @@ func NewIstioVirtualServiceSource(
 	serviceInformer := informerFactory.Core().V1().Services()
 	istioInformerFactory := istioinformers.NewSharedInformerFactoryWithOptions(istioClient, 0, istioinformers.WithNamespace(namespace))
 	virtualServiceInformer := istioInformerFactory.Networking().V1alpha3().VirtualServices()
+	gatewayInformer := istioInformerFactory.Networking().V1alpha3().Gateways()
 
 	// Add default resource event handlers to properly initialize informer.
 	serviceInformer.Informer().AddEventHandler(
@@ -97,6 +99,14 @@ func NewIstioVirtualServiceSource(
 		},
 	)
 
+	gatewayInformer.Informer().AddEventHandler(
+		cache.ResourceEventHandlerFuncs{
+			AddFunc: func(obj interface{}) {
+				log.Debug("gateway added")
+			},
+		},
+	)
+
 	informerFactory.Start(ctx.Done())
 	istioInformerFactory.Start(ctx.Done())
 
@@ -118,6 +128,7 @@ func NewIstioVirtualServiceSource(
 		ignoreHostnameAnnotation: ignoreHostnameAnnotation,
 		serviceInformer:          serviceInformer,
 		virtualserviceInformer:   virtualServiceInformer,
+		gatewayInformer:          gatewayInformer,
 	}, nil
 }
 
@@ -186,7 +197,7 @@ func (sc *virtualServiceSource) AddEventHandler(ctx context.Context, handler fun
 	sc.virtualserviceInformer.Informer().AddEventHandler(eventHandlerFunc(handler))
 }
 
-func (sc *virtualServiceSource) getGateway(ctx context.Context, gatewayStr string, virtualService *networkingv1alpha3.VirtualService) (*networkingv1alpha3.Gateway, error) {
+func (sc *virtualServiceSource) getGateway(_ context.Context, gatewayStr string, virtualService *networkingv1alpha3.VirtualService) (*networkingv1alpha3.Gateway, error) {
 	if gatewayStr == "" || gatewayStr == IstioMeshGateway {
 		// This refers to "all sidecars in the mesh"; ignore.
 		return nil, nil
@@ -201,7 +212,7 @@ func (sc *virtualServiceSource) getGateway(ctx context.Context, gatewayStr strin
 		namespace = virtualService.Namespace
 	}
 
-	gateway, err := sc.istioClient.NetworkingV1alpha3().Gateways(namespace).Get(ctx, name, metav1.GetOptions{})
+	gateway, err := sc.gatewayInformer.Lister().Gateways(namespace).Get(name)
 	if errors.IsNotFound(err) {
 		log.Warnf("VirtualService (%s/%s) references non-existent gateway: %s ", virtualService.Namespace, virtualService.Name, gatewayStr)
 		return nil, nil

source/istio_virtualservice_test.go

@@ -29,13 +29,10 @@ import (
 	istionetworking "istio.io/api/networking/v1alpha3"
 	networkingv1alpha3 "istio.io/client-go/pkg/apis/networking/v1alpha3"
 	istiofake "istio.io/client-go/pkg/clientset/versioned/fake"
-	fakenetworking3 "istio.io/client-go/pkg/clientset/versioned/typed/networking/v1alpha3/fake"
 	v1 "k8s.io/api/core/v1"
 	networkv1 "k8s.io/api/networking/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/kubernetes/fake"
-	k8sclienttesting "k8s.io/client-go/testing"
 
 	"sigs.k8s.io/external-dns/endpoint"
 )
@@ -700,6 +697,20 @@ func testEndpointsFromVirtualServiceConfig(t *testing.T) {
 		t.Run(ti.title, func(t *testing.T) {
 			t.Parallel()
 
+			for i := range ti.ingresses {
+				if ti.ingresses[i].namespace == "" {
+					ti.ingresses[i].namespace = "test"
+				}
+			}
+
+			if ti.gwconfig.namespace == "" {
+				ti.gwconfig.namespace = "test"
+			}
+
+			if ti.vsconfig.namespace == "" {
+				ti.vsconfig.namespace = "test"
+			}
+
 			if source, err := newTestVirtualServiceSource(ti.lbServices, ti.ingresses, []fakeGatewayConfig{ti.gwconfig}); err != nil {
 				require.NoError(t, err)
 			} else if endpoints, err := source.endpointsFromVirtualService(context.Background(), ti.vsconfig.Config()); err != nil {
@@ -2182,34 +2193,6 @@ func TestVirtualServiceSourceGetGateway(t *testing.T) {
 			Spec:       istionetworking.Gateway{},
 			Status:     v1alpha1.IstioStatus{},
 		}, expectedErrStr: ""},
-		{name: "ErrorGettingGateway", fields: fields{
-			virtualServiceSource: func() *virtualServiceSource {
-				istioFake := istiofake.NewSimpleClientset()
-				istioFake.NetworkingV1alpha3().(*fakenetworking3.FakeNetworkingV1alpha3).PrependReactor("get", "gateways", func(action k8sclienttesting.Action) (handled bool, ret runtime.Object, err error) {
-					return true, &networkingv1alpha3.Gateway{}, fmt.Errorf("error getting gateway")
-				})
-				vs, _ := NewIstioVirtualServiceSource(
-					context.TODO(),
-					fake.NewSimpleClientset(),
-					istioFake,
-					"",
-					"",
-					"{{.Name}}",
-					false,
-					false,
-				)
-				return vs.(*virtualServiceSource)
-			}(),
-		}, args: args{
-			ctx:        context.TODO(),
-			gatewayStr: "foo/bar",
-			virtualService: &networkingv1alpha3.VirtualService{
-				TypeMeta:   metav1.TypeMeta{},
-				ObjectMeta: metav1.ObjectMeta{Name: "gateway", Namespace: "error"},
-				Spec:       istionetworking.VirtualService{},
-				Status:     v1alpha1.IstioStatus{},
-			},
-		}, want: nil, expectedErrStr: "error getting gateway"},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {