Fixed a bug that mistake use newObj as oldObj in endpoint slice update

Author: fatkun

pkg/controller/endpointslice/BUILD

@@ -68,6 +68,7 @@ go_test(
         "//staging/src/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/intstr:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/rand:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//staging/src/k8s.io/client-go/informers:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes/fake:go_default_library",
         "//staging/src/k8s.io/client-go/listers/core/v1:go_default_library",

pkg/controller/endpointslice/endpointslice_controller.go

@@ -404,7 +404,7 @@ func (c *Controller) onEndpointSliceAdd(obj interface{}) {
 // endpointSliceTracker or the managed-by value of the EndpointSlice has changed
 // from or to this controller.
 func (c *Controller) onEndpointSliceUpdate(prevObj, obj interface{}) {
-	prevEndpointSlice := obj.(*discovery.EndpointSlice)
+	prevEndpointSlice := prevObj.(*discovery.EndpointSlice)
 	endpointSlice := obj.(*discovery.EndpointSlice)
 	if endpointSlice == nil || prevEndpointSlice == nil {
 		utilruntime.HandleError(fmt.Errorf("Invalid EndpointSlice provided to onEndpointSliceUpdate()"))

pkg/controller/endpointslice/endpointslice_controller_test.go

@@ -30,6 +30,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/intstr"
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes/fake"
 	k8stesting "k8s.io/client-go/testing"
@@ -274,6 +275,39 @@ func TestSyncServiceEndpointSliceLabelSelection(t *testing.T) {
 	cmc.Check(t)
 }
 
+func TestOnEndpointSliceUpdate(t *testing.T) {
+	_, esController := newController([]string{"node-1"}, time.Duration(0))
+	ns := metav1.NamespaceDefault
+	serviceName := "testing-1"
+	epSlice1 := &discovery.EndpointSlice{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "matching-1",
+			Namespace: ns,
+			Labels: map[string]string{
+				discovery.LabelServiceName: serviceName,
+				discovery.LabelManagedBy:   controllerName,
+			},
+		},
+		AddressType: discovery.AddressTypeIPv4,
+	}
+
+	epSlice2 := epSlice1.DeepCopy()
+	epSlice2.Labels[discovery.LabelManagedBy] = "something else"
+
+	assert.Equal(t, 0, esController.queue.Len())
+	esController.onEndpointSliceUpdate(epSlice1, epSlice2)
+	err := wait.PollImmediate(100*time.Millisecond, 3*time.Second, func() (bool, error) {
+		if esController.queue.Len() > 0 {
+			return true, nil
+		}
+		return false, nil
+	})
+	if err != nil {
+		t.Fatalf("unexpected error waiting for add to queue")
+	}
+	assert.Equal(t, 1, esController.queue.Len())
+}
+
 // Ensure SyncService handles a variety of protocols and IPs appropriately.
 func TestSyncServiceFull(t *testing.T) {
 	client, esController := newController([]string{"node-1"}, time.Duration(0))