Merge pull request #120872 from p0lyn0mial/upstream-has-initial-events-annotation

storage/util: introduce HasInitialEventsEndBookmarkAnnotation

staging/src/k8s.io/apiserver/pkg/storage/util.go

@@ -29,6 +29,13 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
+const (
+	// initialEventsAnnotationKey the name of the key
+	// under which an annotation marking the end of list stream
+	// is kept.
+	initialEventsAnnotationKey = "k8s.io/initial-events-end"
+)
+
 type SimpleUpdateFunc func(runtime.Object) (runtime.Object, error)
 
 // SimpleUpdateFunc converts SimpleUpdateFunc into UpdateFunc
@@ -137,7 +144,18 @@ func AnnotateInitialEventsEndBookmark(obj runtime.Object) error {
 	if objAnnotations == nil {
 		objAnnotations = map[string]string{}
 	}
-	objAnnotations["k8s.io/initial-events-end"] = "true"
+	objAnnotations[initialEventsAnnotationKey] = "true"
 	objMeta.SetAnnotations(objAnnotations)
 	return nil
 }
+
+// HasInitialEventsEndBookmarkAnnotation checks the presence of the
+// special annotation which marks that the initial events have been sent.
+func HasInitialEventsEndBookmarkAnnotation(obj runtime.Object) (bool, error) {
+	objMeta, err := meta.Accessor(obj)
+	if err != nil {
+		return false, err
+	}
+	objAnnotations := objMeta.GetAnnotations()
+	return objAnnotations[initialEventsAnnotationKey] == "true", nil
+}

staging/src/k8s.io/apiserver/pkg/storage/util_test.go

@@ -146,3 +146,42 @@ func TestGetCurrentResourceVersionFromStorage(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, currentPodRV, podRV, "didn't expect to see the pod's RV changed")
 }
+
+func TestHasInitialEventsEndBookmarkAnnotation(t *testing.T) {
+	createPod := func(name string) *example.Pod {
+		return &example.Pod{ObjectMeta: metav1.ObjectMeta{Name: name}}
+	}
+	createAnnotatedPod := func(name, value string) *example.Pod {
+		p := createPod(name)
+		p.Annotations = map[string]string{}
+		p.Annotations["k8s.io/initial-events-end"] = value
+		return p
+	}
+	scenarios := []struct {
+		name             string
+		object           runtime.Object
+		expectAnnotation bool
+	}{
+		{
+			name:             "a standard obj with the initial-events-end annotation set to true",
+			object:           createAnnotatedPod("p1", "true"),
+			expectAnnotation: true,
+		},
+		{
+			name:   "a standard obj with the initial-events-end annotation set to false",
+			object: createAnnotatedPod("p1", "false"),
+		},
+		{
+			name:   "a standard obj without the annotation",
+			object: createPod("p1"),
+		},
+	}
+
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			hasAnnotation, err := storage.HasInitialEventsEndBookmarkAnnotation(scenario.object)
+			require.NoError(t, err)
+			require.Equal(t, scenario.expectAnnotation, hasAnnotation)
+		})
+	}
+}