Merge pull request #46648 from caesarxuchao/fix-46631

Automatic merge from submit-queue (batch tested with PRs 46648, 46500, 46238, 46668, 46557)

Fix initializer_manager_test.go flake

Fixes https://github.com/kubernetes/kubernetes/issues/46631.

I reproduced the flake after 98 runs.

With the fix, it's not flaky in 1000 runs.

pkg/kubeapiserver/admission/configuration/configuration_manager.go

@@ -46,6 +46,8 @@ type poller struct {
 	// if the number of consecutive read failure equals or exceeds the failureThreshold , the
 	// configuration is regarded as not ready.
 	failureThreshold int
+	// number of consecutive failures so far.
+	failures int
 	// if the configuration is regarded as ready.
 	ready               bool
 	mergedConfiguration runtime.Object
@@ -84,17 +86,18 @@ func (a *poller) setConfigurationAndReady(value runtime.Object) {
 }
 
 func (a *poller) Run(stopCh <-chan struct{}) {
-	var failure int
-	go wait.Until(func() {
-		configuration, err := a.get()
-		if err != nil {
-			failure++
-			if failure >= a.failureThreshold {
-				a.notReady()
-			}
-			return
-		}
-		failure = 0
-		a.setConfigurationAndReady(configuration)
-	}, a.interval, stopCh)
+	go wait.Until(a.sync, a.interval, stopCh)
+}
+
+func (a *poller) sync() {
+	configuration, err := a.get()
+	if err != nil {
+		a.failures++
+		if a.failures >= a.failureThreshold {
+			a.notReady()
+		}
+		return
+	}
+	a.failures = 0
+	a.setConfigurationAndReady(configuration)
 }

pkg/kubeapiserver/admission/configuration/initializer_manager_test.go

@@ -30,7 +30,6 @@ type mockLister struct {
 	invoked           int
 	successes         int
 	failures          int
-	stopCh            chan struct{}
 	configurationList v1alpha1.InitializerConfigurationList
 	t                 *testing.T
 }
@@ -40,20 +39,15 @@ func newMockLister(successes, failures int, configurationList v1alpha1.Initializ
 		failures:          failures,
 		successes:         successes,
 		configurationList: configurationList,
-		stopCh:            make(chan struct{}),
 		t:                 t,
 	}
 }
 
 // The first List will be successful; the next m.failures List will
-// fail; the next m.successes List will be successful; the stopCh is closed at
-// the 1+m.failures+m.successes call.
+// fail; the next m.successes List will be successful
+// List should only be called 1+m.failures+m.successes times.
 func (m *mockLister) List(options metav1.ListOptions) (*v1alpha1.InitializerConfigurationList, error) {
 	m.invoked++
-	// m.successes could be 0, so call this `if` first.
-	if m.invoked == 1+m.failures+m.successes {
-		close(m.stopCh)
-	}
 	if m.invoked == 1 {
 		return &m.configurationList, nil
 	}
@@ -63,7 +57,7 @@ func (m *mockLister) List(options metav1.ListOptions) (*v1alpha1.InitializerConf
 	if m.invoked <= 1+m.failures+m.successes {
 		return &m.configurationList, nil
 	}
-	m.t.Fatalf("unexpected call to List, stopCh has been closed at the %d time call", 1+m.successes+m.failures)
+	m.t.Fatalf("unexpected call to List, should only be called %d times", 1+m.successes+m.failures)
 	return nil, nil
 }
 
@@ -103,8 +97,9 @@ func TestConfiguration(t *testing.T) {
 		mock := newMockLister(c.successes, c.failures, v1alpha1.InitializerConfigurationList{}, t)
 		manager := NewInitializerConfigurationManager(mock)
 		manager.interval = 1 * time.Millisecond
-		manager.Run(mock.stopCh)
-		<-mock.stopCh
+		for i := 0; i < 1+c.successes+c.failures; i++ {
+			manager.sync()
+		}
 		_, err := manager.Initializers()
 		if err != nil && c.expectReady {
 			t.Errorf("case %s, expect ready, got: %v", c.name, err)