updated to handle cronjob flow

cmd/descheduler/app/server.go

@@ -73,7 +73,7 @@ func NewDeschedulerCommand(out io.Writer) *cobra.Command {
 			}
 
 			ctx, done := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
-			defer done()
+
 			pathRecorderMux := mux.NewPathRecorderMux("descheduler")
 			if !s.DisableMetrics {
 				pathRecorderMux.Handle("/metrics", legacyregistry.HandlerWithReset())
@@ -81,15 +81,20 @@ func NewDeschedulerCommand(out io.Writer) *cobra.Command {
 
 			healthz.InstallHandler(pathRecorderMux, healthz.NamedCheck("Descheduler", healthz.PingHealthz.Check))
 
-			if _, err := SecureServing.Serve(pathRecorderMux, 0, ctx.Done()); err != nil {
+			stoppedCh, err := SecureServing.Serve(pathRecorderMux, 0, ctx.Done())
+			if err != nil {
 				klog.Fatalf("failed to start secure server: %v", err)
 				return
 			}
 
-			err := Run(ctx, s)
+			err = Run(ctx, s)
 			if err != nil {
 				klog.ErrorS(err, "descheduler server")
 			}
+
+			done()
+			// wait for metrics server to close
+			<-stoppedCh
 		},
 	}
 	cmd.SetOut(out)

pkg/descheduler/descheduler.go

@@ -69,13 +69,7 @@ func Run(ctx context.Context, rs *options.DeschedulerServer) error {
 		return err
 	}
 
-	// tie in root ctx with our wait stopChannel
-	stopChannel := make(chan struct{})
-	go func() {
-		<-ctx.Done()
-		close(stopChannel)
-	}()
-	return RunDeschedulerStrategies(ctx, rs, deschedulerPolicy, evictionPolicyGroupVersion, stopChannel)
+	return RunDeschedulerStrategies(ctx, rs, deschedulerPolicy, evictionPolicyGroupVersion)
 }
 
 type strategyFunction func(ctx context.Context, client clientset.Interface, strategy api.DeschedulerStrategy, nodes []*v1.Node, podEvictor *evictions.PodEvictor, getPodsAssignedToNode podutil.GetPodsAssignedToNodeFunc)
@@ -156,13 +150,16 @@ func cachedClient(
 	return fakeClient, nil
 }
 
-func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer, deschedulerPolicy *api.DeschedulerPolicy, evictionPolicyGroupVersion string, stopChannel chan struct{}) error {
+func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer, deschedulerPolicy *api.DeschedulerPolicy, evictionPolicyGroupVersion string) error {
 	sharedInformerFactory := informers.NewSharedInformerFactory(rs.Client, 0)
 	nodeInformer := sharedInformerFactory.Core().V1().Nodes()
 	podInformer := sharedInformerFactory.Core().V1().Pods()
 	namespaceInformer := sharedInformerFactory.Core().V1().Namespaces()
 	priorityClassInformer := sharedInformerFactory.Scheduling().V1().PriorityClasses()
 
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
 	// create the informers
 	namespaceInformer.Informer()
 	priorityClassInformer.Informer()
@@ -172,8 +169,8 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 		return fmt.Errorf("build get pods assigned to node function error: %v", err)
 	}
 
-	sharedInformerFactory.Start(stopChannel)
-	sharedInformerFactory.WaitForCacheSync(stopChannel)
+	sharedInformerFactory.Start(ctx.Done())
+	sharedInformerFactory.WaitForCacheSync(ctx.Done())
 
 	strategyFuncs := map[api.StrategyName]strategyFunction{
 		"RemoveDuplicates":                            strategies.RemoveDuplicatePods,
@@ -223,13 +220,13 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 		nodes, err := nodeutil.ReadyNodes(ctx, rs.Client, nodeInformer, nodeSelector)
 		if err != nil {
 			klog.V(1).InfoS("Unable to get ready nodes", "err", err)
-			close(stopChannel)
+			cancel()
 			return
 		}
 
 		if len(nodes) <= 1 {
 			klog.V(1).InfoS("The cluster size is 0 or 1 meaning eviction causes service disruption or degradation. So aborting..")
-			close(stopChannel)
+			cancel()
 			return
 		}
 
@@ -292,9 +289,9 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 
 		// If there was no interval specified, send a signal to the stopChannel to end the wait.Until loop after 1 iteration
 		if rs.DeschedulingInterval.Seconds() == 0 {
-			close(stopChannel)
+			cancel()
 		}
-	}, rs.DeschedulingInterval, stopChannel)
+	}, rs.DeschedulingInterval, ctx.Done())
 
 	return nil
 }

pkg/descheduler/descheduler_test.go

@@ -35,9 +35,6 @@ func TestTaintsUpdated(t *testing.T) {
 		},
 	}
 
-	stopChannel := make(chan struct{})
-	defer close(stopChannel)
-
 	rs, err := options.NewDeschedulerServer()
 	if err != nil {
 		t.Fatalf("Unable to initialize server: %v", err)
@@ -47,7 +44,7 @@ func TestTaintsUpdated(t *testing.T) {
 	errChan := make(chan error, 1)
 	defer close(errChan)
 	go func() {
-		err := RunDeschedulerStrategies(ctx, rs, dp, "v1beta1", stopChannel)
+		err := RunDeschedulerStrategies(ctx, rs, dp, "v1beta1")
 		errChan <- err
 	}()
 	select {
@@ -101,3 +98,69 @@ func TestTaintsUpdated(t *testing.T) {
 		t.Fatalf("Unable to evict pod, node taint did not get propagated to descheduler strategies")
 	}
 }
+
+func TestRootCancel(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	n1 := test.BuildTestNode("n1", 2000, 3000, 10, nil)
+	n2 := test.BuildTestNode("n2", 2000, 3000, 10, nil)
+	client := fakeclientset.NewSimpleClientset(n1, n2)
+	dp := &api.DeschedulerPolicy{
+		Strategies: api.StrategyList{}, // no strategies needed for this test
+	}
+
+	rs, err := options.NewDeschedulerServer()
+	if err != nil {
+		t.Fatalf("Unable to initialize server: %v", err)
+	}
+	rs.Client = client
+	rs.DeschedulingInterval = 100 * time.Millisecond
+	errChan := make(chan error, 1)
+	defer close(errChan)
+
+	go func() {
+		err := RunDeschedulerStrategies(ctx, rs, dp, "v1beta1")
+		errChan <- err
+	}()
+	cancel()
+	select {
+	case err := <-errChan:
+		if err != nil {
+			t.Fatalf("Unable to run descheduler strategies: %v", err)
+		}
+	case <-time.After(1 * time.Second):
+		t.Fatal("Root ctx should have canceled immediately")
+	}
+}
+
+func TestRootCancelWithNoInterval(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	n1 := test.BuildTestNode("n1", 2000, 3000, 10, nil)
+	n2 := test.BuildTestNode("n2", 2000, 3000, 10, nil)
+	client := fakeclientset.NewSimpleClientset(n1, n2)
+	dp := &api.DeschedulerPolicy{
+		Strategies: api.StrategyList{}, // no strategies needed for this test
+	}
+
+	rs, err := options.NewDeschedulerServer()
+	if err != nil {
+		t.Fatalf("Unable to initialize server: %v", err)
+	}
+	rs.Client = client
+	rs.DeschedulingInterval = 0
+	errChan := make(chan error, 1)
+	defer close(errChan)
+
+	go func() {
+		err := RunDeschedulerStrategies(ctx, rs, dp, "v1beta1")
+		errChan <- err
+	}()
+	cancel()
+	select {
+	case err := <-errChan:
+		if err != nil {
+			t.Fatalf("Unable to run descheduler strategies: %v", err)
+		}
+	case <-time.After(1 * time.Second):
+		t.Fatal("Root ctx should have canceled immediately")
+	}
+}

test/e2e/e2e_test.go

@@ -984,9 +984,7 @@ func TestDeschedulingInterval(t *testing.T) {
 		if err != nil || len(evictionPolicyGroupVersion) == 0 {
 			t.Errorf("Error when checking support for eviction: %v", err)
 		}
-
-		stopChannel := make(chan struct{})
-		if err := descheduler.RunDeschedulerStrategies(ctx, s, deschedulerPolicy, evictionPolicyGroupVersion, stopChannel); err != nil {
+		if err := descheduler.RunDeschedulerStrategies(ctx, s, deschedulerPolicy, evictionPolicyGroupVersion); err != nil {
 			t.Errorf("Error running descheduler strategies: %+v", err)
 		}
 		c <- true