add addafter method that permits enqueueing the objects themselves (#408)

controller/controller.go

@@ -117,6 +117,17 @@ func NewImpl(r Reconciler, logger *zap.SugaredLogger, workQueueName string, repo
 	}
 }
 
+// EnqueueAfter takes a resource, converts it into a namespace/name string,
+// and passes it to EnqueueKey.
+func (c *Impl) EnqueueAfter(obj interface{}, after time.Duration) {
+	key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(obj)
+	if err != nil {
+		c.logger.Errorw("Enqueue", zap.Error(err))
+		return
+	}
+	c.EnqueueKeyAfter(key, after)
+}
+
 // Enqueue takes a resource, converts it into a namespace/name string,
 // and passes it to EnqueueKey.
 func (c *Impl) Enqueue(obj interface{}) {

controller/controller_test.go

@@ -419,6 +419,41 @@ func TestEnqueues(t *testing.T) {
 }
 
 func TestEnqeueAfter(t *testing.T) {
+	impl := NewImpl(&NopReconciler{}, TestLogger(t), "Testing", &FakeStatsReporter{})
+	impl.EnqueueAfter(&Resource{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "for",
+			Namespace: "waiting",
+		},
+	}, time.Second)
+	impl.EnqueueAfter(&Resource{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "waterfall",
+			Namespace: "the",
+		},
+	}, 300*time.Millisecond)
+	impl.EnqueueAfter(&Resource{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "to",
+			Namespace: "fall",
+		},
+	}, 2*time.Second)
+	time.Sleep(50 * time.Millisecond)
+	if got, want := impl.WorkQueue.Len(), 0; got != want {
+		t.Errorf("|Queue| = %d, want: %d", got, want)
+	}
+	// Sleep the remaining time.
+	time.Sleep(time.Second - 50*time.Millisecond)
+	if got, want := impl.WorkQueue.Len(), 2; got != want {
+		t.Errorf("|Queue| = %d, want: %d", got, want)
+	}
+	impl.WorkQueue.ShutDown()
+	if got, want := drainWorkQueue(impl.WorkQueue), []string{"the/waterfall", "waiting/for"}; !cmp.Equal(got, want) {
+		t.Errorf("Queue = %v, want: %v, diff: %s", got, want, cmp.Diff(got, want))
+	}
+}
+
+func TestEnqeueKeyAfter(t *testing.T) {
 	impl := NewImpl(&NopReconciler{}, TestLogger(t), "Testing", &FakeStatsReporter{})
 	impl.EnqueueKeyAfter("waiting/for", time.Second)
 	impl.EnqueueKeyAfter("the/waterfall", time.Second>>1)