Fix select annotation changed predicate (#4967)

It was mistakenly classifying creates as containing an annotation
change. This was previously harmless because we always reconciled the
resource (say, ResourceGroup) if the obj was created anyway, but now
that we also use this predicate for watching namespaces, we do not want
events on namespace create, only on namespace updates that contain an
annotation change.

Author: matthchr

v2/internal/reconcilers/generic/register.go

@@ -204,7 +204,9 @@ func registerNamespaceWatcher(kubeclient kubeclient.Client, gvk schema.GroupVers
 		}
 		// list the objects for the current kind
 
-		log.V(Verbose).Info("Detected namespace reconcile-policy annotation", "namespace", obj.GetName())
+		log.V(Verbose).Info("Detected namespace reconcile-policy annotation change",
+			"namespace", obj.GetName(),
+			"reconcile-policy", obj.GetAnnotations()["serviceoperator.azure.com/reconcile-policy"])
 		for _, el := range aList.Items {
 			if _, ok := el.GetAnnotations()["serviceoperator.azure.com/reconcile-policy"]; ok {
 				// If the annotation is defined for the object, there's no need to reconcile it and we skip the object

v2/internal/util/predicates/select_annotations_predicate.go

@@ -36,6 +36,21 @@ type selectAnnotationChangedPredicate struct {
 
 var _ predicate.Predicate = selectAnnotationChangedPredicate{}
 
+// Create implements CreateEvent filter - we don't care about create events for annotation changes.
+func (p selectAnnotationChangedPredicate) Create(e event.CreateEvent) bool {
+	return false
+}
+
+// Delete implements DeleteEvent filter - we don't care about delete events for annotation changes.
+func (p selectAnnotationChangedPredicate) Delete(e event.DeleteEvent) bool {
+	return false
+}
+
+// Generic implements GenericEvent filter - we don't care about generic events for annotation changes.
+func (p selectAnnotationChangedPredicate) Generic(e event.GenericEvent) bool {
+	return false
+}
+
 // Update implements UpdateEvent filter for annotation changes.
 func (p selectAnnotationChangedPredicate) Update(e event.UpdateEvent) bool {
 	if e.ObjectOld == nil {

v2/internal/util/predicates/select_annotations_predicate_test.go

@@ -144,6 +144,81 @@ func Test_SelectAnnotationsChangedPredicate_DetectsChanges(t *testing.T) {
 	}
 }
 
+func Test_SelectAnnotationsChangedPredicate_CreateEvent(t *testing.T) {
+	t.Parallel()
+	g := NewGomegaWithT(t)
+
+	annotationKey := "foobar"
+	predicate := predicates.MakeSelectAnnotationChangedPredicate(
+		map[string]predicates.HasAnnotationChanged{
+			annotationKey: predicates.HasBasicAnnotationChanged,
+		})
+
+	watchedObj := &SampleObj{
+		ObjectMeta: metav1.ObjectMeta{
+			Annotations: map[string]string{
+				annotationKey: "1234",
+			},
+		},
+	}
+
+	result := predicate.Create(
+		event.CreateEvent{
+			Object: watchedObj,
+		})
+	g.Expect(result).To(BeFalse())
+}
+
+func Test_SelectAnnotationsChangedPredicate_DeleteEvent(t *testing.T) {
+	t.Parallel()
+	g := NewGomegaWithT(t)
+
+	annotationKey := "foobar"
+	predicate := predicates.MakeSelectAnnotationChangedPredicate(
+		map[string]predicates.HasAnnotationChanged{
+			annotationKey: predicates.HasBasicAnnotationChanged,
+		})
+
+	watchedObj := &SampleObj{
+		ObjectMeta: metav1.ObjectMeta{
+			Annotations: map[string]string{
+				annotationKey: "1234",
+			},
+		},
+	}
+
+	result := predicate.Delete(
+		event.DeleteEvent{
+			Object: watchedObj,
+		})
+	g.Expect(result).To(BeFalse())
+}
+
+func Test_SelectAnnotationsChangedPredicate_GenericEvent(t *testing.T) {
+	t.Parallel()
+	g := NewGomegaWithT(t)
+
+	annotationKey := "foobar"
+	predicate := predicates.MakeSelectAnnotationChangedPredicate(
+		map[string]predicates.HasAnnotationChanged{
+			annotationKey: predicates.HasBasicAnnotationChanged,
+		})
+
+	watchedObj := &SampleObj{
+		ObjectMeta: metav1.ObjectMeta{
+			Annotations: map[string]string{
+				annotationKey: "1234",
+			},
+		},
+	}
+
+	result := predicate.Generic(
+		event.GenericEvent{
+			Object: watchedObj,
+		})
+	g.Expect(result).To(BeFalse())
+}
+
 func Test_SelectAnnotationsChangedPredicate_MissingAnnotationPassesNilToHandler(t *testing.T) {
 	t.Parallel()
 	g := NewGomegaWithT(t)