Promote APIServerIdentity to Beta

cmd/kube-apiserver/app/options/options.go

@@ -82,9 +82,6 @@ type ServerRunOptions struct {
 	MasterCount            int
 	EndpointReconcilerType string
 
-	IdentityLeaseDurationSeconds      int
-	IdentityLeaseRenewIntervalSeconds int
-
 	ServiceAccountSigningKeyFile     string
 	ServiceAccountIssuer             serviceaccount.TokenGenerator
 	ServiceAccountTokenMaxExpiration time.Duration
@@ -110,12 +107,10 @@ func NewServerRunOptions() *ServerRunOptions {
 		Logs:                    logs.NewOptions(),
 		Traces:                  genericoptions.NewTracingOptions(),
 
-		EnableLogsHandler:                 true,
-		EventTTL:                          1 * time.Hour,
-		MasterCount:                       1,
-		EndpointReconcilerType:            string(reconcilers.LeaseEndpointReconcilerType),
-		IdentityLeaseDurationSeconds:      3600,
-		IdentityLeaseRenewIntervalSeconds: 10,
+		EnableLogsHandler:      true,
+		EventTTL:               1 * time.Hour,
+		MasterCount:            1,
+		EndpointReconcilerType: string(reconcilers.LeaseEndpointReconcilerType),
 		KubeletConfig: kubeletclient.KubeletClientConfig{
 			Port:         ports.KubeletPort,
 			ReadOnlyPort: ports.KubeletReadOnlyPort,
@@ -185,12 +180,6 @@ func (s *ServerRunOptions) Flags() (fss cliflag.NamedFlagSets) {
 	fs.StringVar(&s.EndpointReconcilerType, "endpoint-reconciler-type", s.EndpointReconcilerType,
 		"Use an endpoint reconciler ("+strings.Join(reconcilers.AllTypes.Names(), ", ")+") master-count is deprecated, and will be removed in a future version.")
 
-	fs.IntVar(&s.IdentityLeaseDurationSeconds, "identity-lease-duration-seconds", s.IdentityLeaseDurationSeconds,
-		"The duration of kube-apiserver lease in seconds, must be a positive number. (In use when the APIServerIdentity feature gate is enabled.)")
-
-	fs.IntVar(&s.IdentityLeaseRenewIntervalSeconds, "identity-lease-renew-interval-seconds", s.IdentityLeaseRenewIntervalSeconds,
-		"The interval of kube-apiserver renewing its lease in seconds, must be a positive number. (In use when the APIServerIdentity feature gate is enabled.)")
-
 	// See #14282 for details on how to test/try this option out.
 	// TODO: remove this comment once this option is tested in CI.
 	fs.IntVar(&s.KubernetesServiceNodePort, "kubernetes-service-node-port", s.KubernetesServiceNodePort, ""+

cmd/kube-apiserver/app/options/options_test.go

@@ -318,8 +318,6 @@ func TestAddFlags(t *testing.T) {
 		Traces: &apiserveroptions.TracingOptions{
 			ConfigFile: "/var/run/kubernetes/tracing_config.yaml",
 		},
-		IdentityLeaseDurationSeconds:        3600,
-		IdentityLeaseRenewIntervalSeconds:   10,
 		AggregatorRejectForwardingRedirects: true,
 	}
 

cmd/kube-apiserver/app/options/validation.go

@@ -142,17 +142,6 @@ func validateAPIPriorityAndFairness(options *ServerRunOptions) []error {
 	return nil
 }
 
-func validateAPIServerIdentity(options *ServerRunOptions) []error {
-	var errs []error
-	if options.IdentityLeaseDurationSeconds <= 0 {
-		errs = append(errs, fmt.Errorf("--identity-lease-duration-seconds should be a positive number, but value '%d' provided", options.IdentityLeaseDurationSeconds))
-	}
-	if options.IdentityLeaseRenewIntervalSeconds <= 0 {
-		errs = append(errs, fmt.Errorf("--identity-lease-renew-interval-seconds should be a positive number, but value '%d' provided", options.IdentityLeaseRenewIntervalSeconds))
-	}
-	return errs
-}
-
 // Validate checks ServerRunOptions and return a slice of found errs.
 func (s *ServerRunOptions) Validate() []error {
 	var errs []error
@@ -171,7 +160,6 @@ func (s *ServerRunOptions) Validate() []error {
 	errs = append(errs, s.APIEnablement.Validate(legacyscheme.Scheme, apiextensionsapiserver.Scheme, aggregatorscheme.Scheme)...)
 	errs = append(errs, validateTokenRequest(s)...)
 	errs = append(errs, s.Metrics.Validate()...)
-	errs = append(errs, validateAPIServerIdentity(s)...)
 
 	return errs
 }

cmd/kube-apiserver/app/server.go

@@ -283,9 +283,6 @@ func CreateKubeAPIServerConfig(s completedServerRunOptions) (
 			ExtendExpiration:            s.Authentication.ServiceAccounts.ExtendExpiration,
 
 			VersionedInformers: versionedInformers,
-
-			IdentityLeaseDurationSeconds:      s.IdentityLeaseDurationSeconds,
-			IdentityLeaseRenewIntervalSeconds: s.IdentityLeaseRenewIntervalSeconds,
 		},
 	}
 

pkg/controlplane/instance.go

@@ -129,6 +129,18 @@ const (
 	repairLoopInterval = 3 * time.Minute
 )
 
+var (
+	// IdentityLeaseGCPeriod is the interval which the lease GC controller checks for expired leases
+	// IdentityLeaseGCPeriod is exposed so integration tests can tune this value.
+	IdentityLeaseGCPeriod = 3600 * time.Second
+	// IdentityLeaseDurationSeconds is the duration of kube-apiserver lease in seconds
+	// IdentityLeaseDurationSeconds is exposed so integration tests can tune this value.
+	IdentityLeaseDurationSeconds = 3600
+	// IdentityLeaseRenewIntervalSeconds is the interval of kube-apiserver renewing its lease in seconds
+	// IdentityLeaseRenewIntervalSeconds is exposed so integration tests can tune this value.
+	IdentityLeaseRenewIntervalPeriod = 10 * time.Second
+)
+
 // ExtraConfig defines extra configuration for the master
 type ExtraConfig struct {
 	ClusterAuthenticationInfo clusterauthenticationtrust.ClusterAuthenticationInfo
@@ -193,9 +205,6 @@ type ExtraConfig struct {
 
 	VersionedInformers informers.SharedInformerFactory
 
-	IdentityLeaseDurationSeconds      int
-	IdentityLeaseRenewIntervalSeconds int
-
 	// RepairServicesInterval interval used by the repair loops for
 	// the Services NodePort and ClusterIP resources
 	RepairServicesInterval time.Duration
@@ -480,9 +489,9 @@ func (c completedConfig) New(delegationTarget genericapiserver.DelegationTarget)
 				clock.RealClock{},
 				kubeClient,
 				holderIdentity,
-				int32(c.ExtraConfig.IdentityLeaseDurationSeconds),
+				int32(IdentityLeaseDurationSeconds),
 				nil,
-				time.Duration(c.ExtraConfig.IdentityLeaseRenewIntervalSeconds)*time.Second,
+				IdentityLeaseRenewIntervalPeriod,
 				leaseName,
 				metav1.NamespaceSystem,
 				labelAPIServerHeartbeat)
@@ -496,7 +505,7 @@ func (c completedConfig) New(delegationTarget genericapiserver.DelegationTarget)
 			}
 			go apiserverleasegc.NewAPIServerLeaseGC(
 				kubeClient,
-				time.Duration(c.ExtraConfig.IdentityLeaseDurationSeconds)*time.Second,
+				IdentityLeaseGCPeriod,
 				metav1.NamespaceSystem,
 				KubeAPIServerIdentityLeaseLabelSelector,
 			).Run(hookContext.StopCh)

staging/src/k8s.io/apiserver/pkg/features/kube_features.go

@@ -216,7 +216,7 @@ var defaultKubernetesFeatureGates = map[featuregate.Feature]featuregate.FeatureS
 
 	APIResponseCompression: {Default: true, PreRelease: featuregate.Beta},
 
-	APIServerIdentity: {Default: false, PreRelease: featuregate.Alpha},
+	APIServerIdentity: {Default: true, PreRelease: featuregate.Beta},
 
 	APIServerTracing: {Default: false, PreRelease: featuregate.Alpha},
 

test/e2e/apimachinery/apiserver_identity.go

@@ -0,0 +1,169 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package apimachinery
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/base32"
+	"errors"
+	"fmt"
+	"net"
+	"strings"
+	"time"
+
+	"github.com/onsi/ginkgo/v2"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/kubernetes/test/e2e/framework"
+	e2enode "k8s.io/kubernetes/test/e2e/framework/node"
+	e2eskipper "k8s.io/kubernetes/test/e2e/framework/skipper"
+	e2essh "k8s.io/kubernetes/test/e2e/framework/ssh"
+	admissionapi "k8s.io/pod-security-admission/api"
+)
+
+func getControlPlaneHostname(node *v1.Node) (string, error) {
+	nodeAddresses := e2enode.GetAddresses(node, v1.NodeExternalIP)
+	if len(nodeAddresses) == 0 {
+		return "", errors.New("no valid addresses to use for SSH")
+	}
+
+	controlPlaneAddress := nodeAddresses[0]
+
+	host := controlPlaneAddress + ":" + e2essh.SSHPort
+	result, err := e2essh.SSH("hostname", host, framework.TestContext.Provider)
+	if err != nil {
+		return "", err
+	}
+
+	if result.Code != 0 {
+		return "", fmt.Errorf("encountered non-zero exit code when running hostname command: %d", result.Code)
+	}
+
+	return strings.TrimSpace(result.Stdout), nil
+}
+
+// restartAPIServer attempts to restart the kube-apiserver on a node
+func restartAPIServer(node *v1.Node) error {
+	nodeAddresses := e2enode.GetAddresses(node, v1.NodeExternalIP)
+	if len(nodeAddresses) == 0 {
+		return errors.New("no valid addresses to use for SSH")
+	}
+
+	controlPlaneAddress := nodeAddresses[0]
+	cmd := "pidof kube-apiserver | xargs sudo kill"
+	framework.Logf("Restarting kube-apiserver via ssh, running: %v", cmd)
+	result, err := e2essh.SSH(cmd, net.JoinHostPort(controlPlaneAddress, e2essh.SSHPort), framework.TestContext.Provider)
+	if err != nil || result.Code != 0 {
+		e2essh.LogResult(result)
+		return fmt.Errorf("couldn't restart kube-apiserver: %v", err)
+	}
+	return nil
+}
+
+// This test requires that --feature-gates=APIServerIdentity=true be set on the apiserver
+var _ = SIGDescribe("kube-apiserver identity [Feature:APIServerIdentity]", func() {
+	f := framework.NewDefaultFramework("kube-apiserver-identity")
+	f.NamespacePodSecurityEnforceLevel = admissionapi.LevelPrivileged
+
+	ginkgo.It("kube-apiserver identity should persist after restart [Disruptive]", func() {
+		e2eskipper.SkipUnlessProviderIs("gce")
+
+		client := f.ClientSet
+
+		var controlPlaneNodes []v1.Node
+		nodes, err := client.CoreV1().Nodes().List(context.TODO(), metav1.ListOptions{})
+		framework.ExpectNoError(err)
+
+		for _, node := range nodes.Items {
+			if _, ok := node.Labels["node-role.kubernetes.io/control-plane"]; ok {
+				controlPlaneNodes = append(controlPlaneNodes, node)
+				continue
+			}
+
+			if _, ok := node.Labels["node-role.kubernetes.io/master"]; ok {
+				controlPlaneNodes = append(controlPlaneNodes, node)
+				continue
+			}
+
+			for _, taint := range node.Spec.Taints {
+				if taint.Key == "node-role.kubernetes.io/master" {
+					controlPlaneNodes = append(controlPlaneNodes, node)
+					break
+				}
+
+				if taint.Key == "node-role.kubernetes.io/control-plane" {
+					controlPlaneNodes = append(controlPlaneNodes, node)
+					break
+				}
+			}
+		}
+
+		leases, err := client.CoordinationV1().Leases(metav1.NamespaceSystem).List(context.TODO(), metav1.ListOptions{
+			LabelSelector: "k8s.io/component=kube-apiserver",
+		})
+		framework.ExpectNoError(err)
+		framework.ExpectEqual(len(leases.Items), len(controlPlaneNodes), "unexpected number of leases")
+
+		for _, node := range controlPlaneNodes {
+			hostname, err := getControlPlaneHostname(&node)
+			framework.ExpectNoError(err)
+
+			hash := sha256.Sum256([]byte(hostname))
+			leaseName := "kube-apiserver-" + strings.ToLower(base32.StdEncoding.WithPadding(base32.NoPadding).EncodeToString(hash[:16]))
+
+			lease, err := client.CoordinationV1().Leases(metav1.NamespaceSystem).Get(context.TODO(), leaseName, metav1.GetOptions{})
+			framework.ExpectNoError(err)
+			oldHolderIdentity := lease.Spec.HolderIdentity
+			lastRenewedTime := lease.Spec.RenewTime
+
+			err = restartAPIServer(&node)
+			framework.ExpectNoError(err)
+
+			err = wait.PollImmediate(time.Second, wait.ForeverTestTimeout, func() (bool, error) {
+				lease, err = client.CoordinationV1().Leases(metav1.NamespaceSystem).Get(context.TODO(), leaseName, metav1.GetOptions{})
+				if err != nil {
+					return false, nil
+				}
+
+				// expect only the holder identity to change after a restart
+				newHolderIdentity := lease.Spec.HolderIdentity
+				if newHolderIdentity == oldHolderIdentity {
+					return false, nil
+				}
+
+				// wait for at least one lease heart beat after the holder identity changes
+				if !lease.Spec.RenewTime.After(lastRenewedTime.Time) {
+					return false, nil
+				}
+
+				return true, nil
+
+			})
+			framework.ExpectNoError(err, "holder identity did not change after a restart")
+		}
+
+		// As long as the hostname of kube-apiserver is unchanged, a restart should not result in new Lease objects.
+		// Check that the number of lease objects remains the same after restarting kube-apiserver.
+		leases, err = client.CoordinationV1().Leases(metav1.NamespaceSystem).List(context.TODO(), metav1.ListOptions{
+			LabelSelector: "k8s.io/component=kube-apiserver",
+		})
+		framework.ExpectNoError(err)
+		framework.ExpectEqual(len(leases.Items), len(controlPlaneNodes), "unexpected number of leases")
+	})
+})

test/integration/controlplane/apiserver_identity_test.go

@@ -99,13 +99,23 @@ func TestCreateLeaseOnStart(t *testing.T) {
 }
 
 func TestLeaseGarbageCollection(t *testing.T) {
+	oldIdentityLeaseDurationSeconds := controlplane.IdentityLeaseDurationSeconds
+	oldIdentityLeaseGCPeriod := controlplane.IdentityLeaseGCPeriod
+	oldIdentityLeaseRenewIntervalPeriod := controlplane.IdentityLeaseRenewIntervalPeriod
+	defer func() {
+		// reset the default values for leases after this test
+		controlplane.IdentityLeaseDurationSeconds = oldIdentityLeaseDurationSeconds
+		controlplane.IdentityLeaseGCPeriod = oldIdentityLeaseGCPeriod
+		controlplane.IdentityLeaseRenewIntervalPeriod = oldIdentityLeaseRenewIntervalPeriod
+	}()
+
+	// Shorten lease parameters so GC behavior can be exercised in integration tests
+	controlplane.IdentityLeaseDurationSeconds = 1
+	controlplane.IdentityLeaseGCPeriod = time.Second
+	controlplane.IdentityLeaseRenewIntervalPeriod = time.Second
+
 	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.APIServerIdentity, true)()
-	result := kubeapiservertesting.StartTestServerOrDie(t, nil,
-		// This shorten the GC check period to make the test run faster.
-		// Since we are testing GC behavior on leases we create, what happens to
-		// the real apiserver lease doesn't matter.
-		[]string{"--identity-lease-duration-seconds=1"},
-		framework.SharedEtcd())
+	result := kubeapiservertesting.StartTestServerOrDie(t, nil, nil, framework.SharedEtcd())
 	defer result.TearDownFn()
 
 	kubeclient, err := kubernetes.NewForConfig(result.ClientConfig)