UPSTREAM: 99735: Promote kubelet graceful node shutdown to beta

pkg/features/kube_features.go

@@ -706,6 +706,7 @@ const (
 
 	// owner: @bobbypage
 	// alpha: v1.20
+	// beta:  v1.21
 	// Adds support for kubelet to detect node shutdown and gracefully terminate pods prior to the node being shutdown.
 	GracefulNodeShutdown featuregate.Feature = "GracefulNodeShutdown"
 
@@ -825,7 +826,7 @@ var defaultKubernetesFeatureGates = map[featuregate.Feature]featuregate.FeatureS
 	SizeMemoryBackedVolumes:                        {Default: false, PreRelease: featuregate.Alpha},
 	ExecProbeTimeout:                               {Default: true, PreRelease: featuregate.GA}, // lock to default in v1.21 and remove in v1.22
 	KubeletCredentialProviders:                     {Default: false, PreRelease: featuregate.Alpha},
-	GracefulNodeShutdown:                           {Default: false, PreRelease: featuregate.Alpha},
+	GracefulNodeShutdown:                           {Default: true, PreRelease: featuregate.Beta},
 	ServiceLBNodePortControl:                       {Default: false, PreRelease: featuregate.Alpha},
 	MixedProtocolLBService:                         {Default: false, PreRelease: featuregate.Alpha},
 

pkg/kubelet/apis/config/types.go

@@ -376,11 +376,15 @@ type KubeletConfiguration struct {
 	// EnableSystemLogHandler enables /logs handler.
 	EnableSystemLogHandler bool
 	// ShutdownGracePeriod specifies the total duration that the node should delay the shutdown and total grace period for pod termination during a node shutdown.
-	// Defaults to 30 seconds, requires GracefulNodeShutdown feature gate to be enabled.
+	// Defaults to 0 seconds.
+	// +featureGate=GracefulNodeShutdown
+	// +optional
 	ShutdownGracePeriod metav1.Duration
 	// ShutdownGracePeriodCriticalPods specifies the duration used to terminate critical pods during a node shutdown. This should be less than ShutdownGracePeriod.
-	// Defaults to 10 seconds, requires GracefulNodeShutdown feature gate to be enabled.
+	// Defaults to 0 seconds.
 	// For example, if ShutdownGracePeriod=30s, and ShutdownGracePeriodCriticalPods=10s, during a node shutdown the first 20 seconds would be reserved for gracefully terminating normal pods, and the last 10 seconds would be reserved for terminating critical pods.
+	// +featureGate=GracefulNodeShutdown
+	// +optional
 	ShutdownGracePeriodCriticalPods metav1.Duration
 }
 

pkg/kubelet/apis/config/validation/validation_test.go

@@ -100,7 +100,6 @@ func TestValidateKubeletConfiguration(t *testing.T) {
 		ShutdownGracePeriodCriticalPods: metav1.Duration{Duration: 0},
 		FeatureGates: map[string]bool{
 			"CustomCPUCFSQuotaPeriod": true,
-			"GracefulNodeShutdown":    true,
 		},
 	}
 	if allErrors := ValidateKubeletConfiguration(successCase2); allErrors != nil {
@@ -133,7 +132,7 @@ func TestValidateKubeletConfiguration(t *testing.T) {
 		NodeLeaseDurationSeconds:        -1,
 		CPUCFSQuotaPeriod:               metav1.Duration{Duration: 100 * time.Millisecond},
 		ShutdownGracePeriod:             metav1.Duration{Duration: 30 * time.Second},
-		ShutdownGracePeriodCriticalPods: metav1.Duration{Duration: 10 * time.Second},
+		ShutdownGracePeriodCriticalPods: metav1.Duration{Duration: 60 * time.Second},
 	}
 	const numErrsErrorCase1 = 28
 	if allErrors := ValidateKubeletConfiguration(errorCase1); len(allErrors.(utilerrors.Aggregate).Errors()) != numErrsErrorCase1 {

pkg/kubelet/kubelet_test.go

@@ -53,6 +53,7 @@ import (
 	"k8s.io/kubernetes/pkg/kubelet/lifecycle"
 	"k8s.io/kubernetes/pkg/kubelet/logs"
 	"k8s.io/kubernetes/pkg/kubelet/network/dns"
+	"k8s.io/kubernetes/pkg/kubelet/nodeshutdown"
 	"k8s.io/kubernetes/pkg/kubelet/pleg"
 	"k8s.io/kubernetes/pkg/kubelet/pluginmanager"
 	kubepod "k8s.io/kubernetes/pkg/kubelet/pod"
@@ -302,6 +303,12 @@ func newTestKubeletWithImageList(
 
 	kubelet.evictionManager = evictionManager
 	kubelet.admitHandlers.AddPodAdmitHandler(evictionAdmitHandler)
+
+	// setup shutdown manager
+	shutdownManager, shutdownAdmitHandler := nodeshutdown.NewManager(kubelet.podManager.GetPods, killPodNow(kubelet.podWorkers, fakeRecorder), func() {}, 0 /* shutdownGracePeriodRequested*/, 0 /*shutdownGracePeriodCriticalPods */)
+	kubelet.shutdownManager = shutdownManager
+	kubelet.admitHandlers.AddPodAdmitHandler(shutdownAdmitHandler)
+
 	// Add this as cleanup predicate pod admitter
 	kubelet.admitHandlers.AddPodAdmitHandler(lifecycle.NewPredicateAdmitHandler(kubelet.getNodeAnyWay, lifecycle.NewAdmissionFailureHandlerStub(), kubelet.containerManager.UpdatePluginResources))
 

pkg/kubelet/nodeshutdown/nodeshutdown_manager_linux.go

@@ -88,10 +88,7 @@ func NewManager(getPodsFunc eviction.ActivePodsFunc, killPodFunc eviction.KillPo
 
 // Start starts the node shutdown manager and will start watching the node for shutdown events.
 func (m *Manager) Start() error {
-	if !utilfeature.DefaultFeatureGate.Enabled(features.GracefulNodeShutdown) {
-		return nil
-	}
-	if m.shutdownGracePeriodRequested == 0 {
+	if !m.isFeatureEnabled() {
 		return nil
 	}
 
@@ -177,9 +174,14 @@ func (m *Manager) aquireInhibitLock() error {
 	return nil
 }
 
+// Returns if the feature is enabled
+func (m *Manager) isFeatureEnabled() bool {
+	return utilfeature.DefaultFeatureGate.Enabled(features.GracefulNodeShutdown) && m.shutdownGracePeriodRequested > 0
+}
+
 // ShutdownStatus will return an error if the node is currently shutting down.
 func (m *Manager) ShutdownStatus() error {
-	if !utilfeature.DefaultFeatureGate.Enabled(features.GracefulNodeShutdown) {
+	if !m.isFeatureEnabled() {
 		return nil
 	}
 

pkg/kubelet/nodeshutdown/nodeshutdown_manager_linux_test.go

@@ -259,3 +259,47 @@ func TestManager(t *testing.T) {
 		})
 	}
 }
+
+func TestFeatureEnabled(t *testing.T) {
+	var tests = []struct {
+		desc                         string
+		shutdownGracePeriodRequested time.Duration
+		featureGateEnabled           bool
+		expectEnabled                bool
+	}{
+		{
+			desc:                         "shutdownGracePeriodRequested 0; disables feature",
+			shutdownGracePeriodRequested: time.Duration(0 * time.Second),
+			featureGateEnabled:           true,
+			expectEnabled:                false,
+		},
+		{
+			desc:                         "feature gate disabled; disables feature",
+			shutdownGracePeriodRequested: time.Duration(100 * time.Second),
+			featureGateEnabled:           false,
+			expectEnabled:                false,
+		},
+		{
+			desc:                         "feature gate enabled; shutdownGracePeriodRequested > 0; enables feature",
+			shutdownGracePeriodRequested: time.Duration(100 * time.Second),
+			featureGateEnabled:           true,
+			expectEnabled:                true,
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.desc, func(t *testing.T) {
+			activePodsFunc := func() []*v1.Pod {
+				return nil
+			}
+			killPodsFunc := func(pod *v1.Pod, status v1.PodStatus, gracePeriodOverride *int64) error {
+				return nil
+			}
+			defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, pkgfeatures.GracefulNodeShutdown, tc.featureGateEnabled)()
+
+			manager, _ := NewManager(activePodsFunc, killPodsFunc, func() {}, tc.shutdownGracePeriodRequested, 0 /*shutdownGracePeriodCriticalPods*/)
+			manager.clock = clock.NewFakeClock(time.Now())
+
+			assert.Equal(t, tc.expectEnabled, manager.isFeatureEnabled())
+		})
+	}
+}

staging/src/k8s.io/kubelet/config/v1beta1/types.go

@@ -816,12 +816,14 @@ type KubeletConfiguration struct {
 	// +optional
 	EnableSystemLogHandler *bool `json:"enableSystemLogHandler,omitempty"`
 	// ShutdownGracePeriod specifies the total duration that the node should delay the shutdown and total grace period for pod termination during a node shutdown.
-	// Default: "30s"
+	// Default: "0s"
+	// +featureGate=GracefulNodeShutdown
 	// +optional
 	ShutdownGracePeriod metav1.Duration `json:"shutdownGracePeriod,omitempty"`
 	// ShutdownGracePeriodCriticalPods specifies the duration used to terminate critical pods during a node shutdown. This should be less than ShutdownGracePeriod.
 	// For example, if ShutdownGracePeriod=30s, and ShutdownGracePeriodCriticalPods=10s, during a node shutdown the first 20 seconds would be reserved for gracefully terminating normal pods, and the last 10 seconds would be reserved for terminating critical pods.
-	// Default: "10s"
+	// Default: "0s"
+	// +featureGate=GracefulNodeShutdown
 	// +optional
 	ShutdownGracePeriodCriticalPods metav1.Duration `json:"shutdownGracePeriodCriticalPods,omitempty"`
 }