CLE controller and client changes

Kubernetes-commit: c47ff1e1a9aec44f262674eb6cdbabf80512d981

tools/leaderelection/leaderelection.go

@@ -159,6 +159,9 @@ type LeaderElectionConfig struct {
 
 	// Name is the name of the resource lock for debugging
 	Name string
+
+	// Coordinated will use the Coordinated Leader Election feature
+	Coordinated bool
 }
 
 // LeaderCallbacks are callbacks that are triggered during certain
@@ -249,7 +252,11 @@ func (le *LeaderElector) acquire(ctx context.Context) bool {
 	desc := le.config.Lock.Describe()
 	klog.Infof("attempting to acquire leader lease %v...", desc)
 	wait.JitterUntil(func() {
-		succeeded = le.tryAcquireOrRenew(ctx)
+		if !le.config.Coordinated {
+			succeeded = le.tryAcquireOrRenew(ctx)
+		} else {
+			succeeded = le.tryCoordinatedRenew(ctx)
+		}
 		le.maybeReportTransition()
 		if !succeeded {
 			klog.V(4).Infof("failed to acquire lease %v", desc)
@@ -272,7 +279,11 @@ func (le *LeaderElector) renew(ctx context.Context) {
 		timeoutCtx, timeoutCancel := context.WithTimeout(ctx, le.config.RenewDeadline)
 		defer timeoutCancel()
 		err := wait.PollImmediateUntil(le.config.RetryPeriod, func() (bool, error) {
-			return le.tryAcquireOrRenew(timeoutCtx), nil
+			if !le.config.Coordinated {
+				return le.tryAcquireOrRenew(timeoutCtx), nil
+			} else {
+				return le.tryCoordinatedRenew(timeoutCtx), nil
+			}
 		}, timeoutCtx.Done())
 
 		le.maybeReportTransition()
@@ -282,7 +293,6 @@ func (le *LeaderElector) renew(ctx context.Context) {
 			return
 		}
 		le.metrics.leaderOff(le.config.Name)
-		klog.Infof("failed to renew lease %v: %v", desc, err)
 		cancel()
 	}, le.config.RetryPeriod, ctx.Done())
 
@@ -315,6 +325,81 @@ func (le *LeaderElector) release() bool {
 	return true
 }
 
+// tryCoordinatedRenew checks if it acquired a lease and tries to renew the
+// lease if it has already been acquired. Returns true on success else returns
+// false.
+func (le *LeaderElector) tryCoordinatedRenew(ctx context.Context) bool {
+	now := metav1.NewTime(le.clock.Now())
+	leaderElectionRecord := rl.LeaderElectionRecord{
+		HolderIdentity:       le.config.Lock.Identity(),
+		LeaseDurationSeconds: int(le.config.LeaseDuration / time.Second),
+		RenewTime:            now,
+		AcquireTime:          now,
+	}
+
+	// 1. obtain the electionRecord
+	oldLeaderElectionRecord, oldLeaderElectionRawRecord, err := le.config.Lock.Get(ctx)
+	if err != nil {
+		if !errors.IsNotFound(err) {
+			klog.Errorf("error retrieving resource lock %v: %v", le.config.Lock.Describe(), err)
+			return false
+		}
+		klog.Infof("lease lock not found: %v", le.config.Lock.Describe())
+		return false
+	}
+
+	// 2. Record obtained, check the Identity & Time
+	if !bytes.Equal(le.observedRawRecord, oldLeaderElectionRawRecord) {
+		le.setObservedRecord(oldLeaderElectionRecord)
+
+		le.observedRawRecord = oldLeaderElectionRawRecord
+	}
+	hasExpired := le.observedTime.Add(time.Second * time.Duration(oldLeaderElectionRecord.LeaseDurationSeconds)).Before(now.Time)
+
+	if hasExpired {
+		klog.Infof("lock has expired: %v", le.config.Lock.Describe())
+		return false
+	}
+
+	if !le.IsLeader() {
+		klog.V(4).Infof("lock is held by %v and has not yet expired: %v", oldLeaderElectionRecord.HolderIdentity, le.config.Lock.Describe())
+		return false
+	}
+
+	// 2b. If the lease has been marked as "end of term", don't renew it
+	if le.IsLeader() && oldLeaderElectionRecord.PreferredHolder != "" {
+		klog.V(4).Infof("lock is marked as 'end of term': %v", le.config.Lock.Describe())
+		// TODO: Instead of letting lease expire, the holder may deleted it directly
+		// This will not be compatible with all controllers, so it needs to be opt-in behavior..
+		// We must ensure all code guarded by this lease has successfully completed
+		// prior to releasing or there may be two processes
+		// simultaneously acting on the critical path.
+		// Usually once this returns false, the process is terminated..
+		// xref: OnStoppedLeading
+		return false
+	}
+
+	// 3. We're going to try to update. The leaderElectionRecord is set to it's default
+	// here. Let's correct it before updating.
+	if le.IsLeader() {
+		leaderElectionRecord.AcquireTime = oldLeaderElectionRecord.AcquireTime
+		leaderElectionRecord.LeaderTransitions = oldLeaderElectionRecord.LeaderTransitions
+		leaderElectionRecord.Strategy = oldLeaderElectionRecord.Strategy
+		le.metrics.slowpathExercised(le.config.Name)
+	} else {
+		leaderElectionRecord.LeaderTransitions = oldLeaderElectionRecord.LeaderTransitions + 1
+	}
+
+	// update the lock itself
+	if err = le.config.Lock.Update(ctx, leaderElectionRecord); err != nil {
+		klog.Errorf("Failed to update lock: %v", err)
+		return false
+	}
+
+	le.setObservedRecord(&leaderElectionRecord)
+	return true
+}
+
 // tryAcquireOrRenew tries to acquire a leader lease if it is not already acquired,
 // else it tries to renew the lease if it has already been acquired. Returns true
 // on success else returns false.

tools/leaderelection/leaderelection_test.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/stretchr/testify/assert"
 	coordinationv1 "k8s.io/api/coordination/v1"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/equality"
@@ -37,8 +38,6 @@ import (
 	rl "k8s.io/client-go/tools/leaderelection/resourcelock"
 	"k8s.io/client-go/tools/record"
 	"k8s.io/utils/clock"
-
-	"github.com/stretchr/testify/assert"
 )
 
 func createLockObject(t *testing.T, objectType, namespace, name string, record *rl.LeaderElectionRecord) (obj runtime.Object) {
@@ -353,6 +352,147 @@ func testTryAcquireOrRenew(t *testing.T, objectType string) {
 	}
 }
 
+func TestTryCoordinatedRenew(t *testing.T) {
+	objectType := "leases"
+	clock := clock.RealClock{}
+	future := clock.Now().Add(1000 * time.Hour)
+
+	tests := []struct {
+		name           string
+		observedRecord rl.LeaderElectionRecord
+		observedTime   time.Time
+		retryAfter     time.Duration
+		reactors       []Reactor
+		expectedEvents []string
+
+		expectSuccess    bool
+		transitionLeader bool
+		outHolder        string
+	}{
+		{
+			name: "don't acquire from led, acked object",
+			reactors: []Reactor{
+				{
+					verb: "get",
+					reaction: func(action fakeclient.Action) (handled bool, ret runtime.Object, err error) {
+						return true, createLockObject(t, objectType, action.GetNamespace(), action.(fakeclient.GetAction).GetName(), &rl.LeaderElectionRecord{HolderIdentity: "bing"}), nil
+					},
+				},
+			},
+			observedTime: future,
+
+			expectSuccess: false,
+			outHolder:     "bing",
+		},
+		{
+			name: "renew already acquired object",
+			reactors: []Reactor{
+				{
+					verb: "get",
+					reaction: func(action fakeclient.Action) (handled bool, ret runtime.Object, err error) {
+						return true, createLockObject(t, objectType, action.GetNamespace(), action.(fakeclient.GetAction).GetName(), &rl.LeaderElectionRecord{HolderIdentity: "baz"}), nil
+					},
+				},
+				{
+					verb: "update",
+					reaction: func(action fakeclient.Action) (handled bool, ret runtime.Object, err error) {
+						return true, action.(fakeclient.CreateAction).GetObject(), nil
+					},
+				},
+			},
+			observedTime:   future,
+			observedRecord: rl.LeaderElectionRecord{HolderIdentity: "baz"},
+
+			expectSuccess: true,
+			outHolder:     "baz",
+		},
+	}
+
+	for i := range tests {
+		test := &tests[i]
+		t.Run(test.name, func(t *testing.T) {
+			// OnNewLeader is called async so we have to wait for it.
+			var wg sync.WaitGroup
+			wg.Add(1)
+			var reportedLeader string
+			var lock rl.Interface
+
+			objectMeta := metav1.ObjectMeta{Namespace: "foo", Name: "bar"}
+			recorder := record.NewFakeRecorder(100)
+			resourceLockConfig := rl.ResourceLockConfig{
+				Identity:      "baz",
+				EventRecorder: recorder,
+			}
+			c := &fake.Clientset{}
+			for _, reactor := range test.reactors {
+				c.AddReactor(reactor.verb, objectType, reactor.reaction)
+			}
+			c.AddReactor("*", "*", func(action fakeclient.Action) (bool, runtime.Object, error) {
+				t.Errorf("unreachable action. testclient called too many times: %+v", action)
+				return true, nil, fmt.Errorf("unreachable action")
+			})
+
+			lock = &rl.LeaseLock{
+				LeaseMeta:  objectMeta,
+				LockConfig: resourceLockConfig,
+				Client:     c.CoordinationV1(),
+			}
+			lec := LeaderElectionConfig{
+				Lock:          lock,
+				LeaseDuration: 10 * time.Second,
+				Callbacks: LeaderCallbacks{
+					OnNewLeader: func(l string) {
+						defer wg.Done()
+						reportedLeader = l
+					},
+				},
+				Coordinated: true,
+			}
+			observedRawRecord := GetRawRecordOrDie(t, objectType, test.observedRecord)
+			le := &LeaderElector{
+				config:            lec,
+				observedRecord:    test.observedRecord,
+				observedRawRecord: observedRawRecord,
+				observedTime:      test.observedTime,
+				clock:             clock,
+				metrics:           globalMetricsFactory.newLeaderMetrics(),
+			}
+			if test.expectSuccess != le.tryCoordinatedRenew(context.Background()) {
+				if test.retryAfter != 0 {
+					time.Sleep(test.retryAfter)
+					if test.expectSuccess != le.tryCoordinatedRenew(context.Background()) {
+						t.Errorf("unexpected result of tryCoordinatedRenew: [succeeded=%v]", !test.expectSuccess)
+					}
+				} else {
+					t.Errorf("unexpected result of gryCoordinatedRenew: [succeeded=%v]", !test.expectSuccess)
+				}
+			}
+
+			le.observedRecord.AcquireTime = metav1.Time{}
+			le.observedRecord.RenewTime = metav1.Time{}
+			if le.observedRecord.HolderIdentity != test.outHolder {
+				t.Errorf("expected holder:\n\t%+v\ngot:\n\t%+v", test.outHolder, le.observedRecord.HolderIdentity)
+			}
+			if len(test.reactors) != len(c.Actions()) {
+				t.Errorf("wrong number of api interactions")
+			}
+			if test.transitionLeader && le.observedRecord.LeaderTransitions != 1 {
+				t.Errorf("leader should have transitioned but did not")
+			}
+			if !test.transitionLeader && le.observedRecord.LeaderTransitions != 0 {
+				t.Errorf("leader should not have transitioned but did")
+			}
+
+			le.maybeReportTransition()
+			wg.Wait()
+			if reportedLeader != test.outHolder {
+				t.Errorf("reported leader was not the new leader. expected %q, got %q", test.outHolder, reportedLeader)
+			}
+			assertEqualEvents(t, test.expectedEvents, recorder.Events)
+		})
+	}
+}
+
 // Will test leader election using lease as the resource
 func TestTryAcquireOrRenewLeases(t *testing.T) {
 	testTryAcquireOrRenew(t, "leases")

tools/leaderelection/leasecandidate.go

@@ -0,0 +1,196 @@
+/*
+Copyright 2024 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 leaderelection
+
+import (
+	"context"
+	"time"
+
+	v1 "k8s.io/api/coordination/v1"
+	v1alpha1 "k8s.io/api/coordination/v1alpha1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes"
+	coordinationv1alpha1client "k8s.io/client-go/kubernetes/typed/coordination/v1alpha1"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/client-go/util/workqueue"
+	"k8s.io/klog/v2"
+	"k8s.io/utils/clock"
+)
+
+const requeueInterval = 5 * time.Minute
+
+type LeaseCandidate struct {
+	LeaseClient            coordinationv1alpha1client.LeaseCandidateInterface
+	LeaseCandidateInformer cache.SharedIndexInformer
+	InformerFactory        informers.SharedInformerFactory
+	HasSynced              cache.InformerSynced
+
+	// At most there will be one item in this Queue (since we only watch one item)
+	queue workqueue.TypedRateLimitingInterface[int]
+
+	name      string
+	namespace string
+
+	// controller lease
+	leaseName string
+
+	Clock clock.Clock
+
+	binaryVersion, emulationVersion string
+	preferredStrategies             []v1.CoordinatedLeaseStrategy
+}
+
+func NewCandidate(clientset kubernetes.Interface,
+	candidateName string,
+	candidateNamespace string,
+	targetLease string,
+	clock clock.Clock,
+	binaryVersion, emulationVersion string,
+	preferredStrategies []v1.CoordinatedLeaseStrategy,
+) (*LeaseCandidate, error) {
+	fieldSelector := fields.OneTermEqualSelector("metadata.name", candidateName).String()
+	// A separate informer factory is required because this must start before informerFactories
+	// are started for leader elected components
+	informerFactory := informers.NewSharedInformerFactoryWithOptions(
+		clientset, 5*time.Minute,
+		informers.WithTweakListOptions(func(options *metav1.ListOptions) {
+			options.FieldSelector = fieldSelector
+		}),
+	)
+	leaseCandidateInformer := informerFactory.Coordination().V1alpha1().LeaseCandidates().Informer()
+
+	lc := &LeaseCandidate{
+		LeaseClient:            clientset.CoordinationV1alpha1().LeaseCandidates(candidateNamespace),
+		LeaseCandidateInformer: leaseCandidateInformer,
+		InformerFactory:        informerFactory,
+		name:                   candidateName,
+		namespace:              candidateNamespace,
+		leaseName:              targetLease,
+		Clock:                  clock,
+		binaryVersion:          binaryVersion,
+		emulationVersion:       emulationVersion,
+		preferredStrategies:    preferredStrategies,
+	}
+	lc.queue = workqueue.NewTypedRateLimitingQueueWithConfig(workqueue.DefaultTypedControllerRateLimiter[int](), workqueue.TypedRateLimitingQueueConfig[int]{Name: "leasecandidate"})
+
+	synced, err := leaseCandidateInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
+		UpdateFunc: func(oldObj, newObj interface{}) {
+			if leasecandidate, ok := newObj.(*v1alpha1.LeaseCandidate); ok {
+				if leasecandidate.Spec.PingTime != nil {
+					lc.enqueueLease()
+				}
+			}
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+	lc.HasSynced = synced.HasSynced
+
+	return lc, nil
+}
+
+func (c *LeaseCandidate) Run(ctx context.Context) {
+	defer c.queue.ShutDown()
+
+	go c.InformerFactory.Start(ctx.Done())
+	if !cache.WaitForNamedCacheSync("leasecandidateclient", ctx.Done(), c.HasSynced) {
+		return
+	}
+
+	c.enqueueLease()
+	go c.runWorker(ctx)
+	<-ctx.Done()
+}
+
+func (c *LeaseCandidate) runWorker(ctx context.Context) {
+	for c.processNextWorkItem(ctx) {
+	}
+}
+
+func (c *LeaseCandidate) processNextWorkItem(ctx context.Context) bool {
+	key, shutdown := c.queue.Get()
+	if shutdown {
+		return false
+	}
+	defer c.queue.Done(key)
+
+	err := c.ensureLease(ctx)
+	if err == nil {
+		c.queue.AddAfter(key, requeueInterval)
+		return true
+	}
+
+	utilruntime.HandleError(err)
+	klog.Infof("processNextWorkItem.AddRateLimited: %v", key)
+	c.queue.AddRateLimited(key)
+
+	return true
+}
+
+func (c *LeaseCandidate) enqueueLease() {
+	c.queue.Add(0)
+}
+
+// ensureLease creates the lease if it does not exist and renew it if it exists. Returns the lease and
+// a bool (true if this call created the lease), or any error that occurs.
+func (c *LeaseCandidate) ensureLease(ctx context.Context) error {
+	lease, err := c.LeaseClient.Get(ctx, c.name, metav1.GetOptions{})
+	if apierrors.IsNotFound(err) {
+		klog.V(2).Infof("Creating lease candidate")
+		// lease does not exist, create it.
+		leaseToCreate := c.newLease()
+		_, err := c.LeaseClient.Create(ctx, leaseToCreate, metav1.CreateOptions{})
+		if err != nil {
+			return err
+		}
+		klog.V(2).Infof("Created lease candidate")
+		return nil
+	} else if err != nil {
+		return err
+	}
+	klog.V(2).Infof("lease candidate exists.. renewing")
+	clone := lease.DeepCopy()
+	clone.Spec.RenewTime = &metav1.MicroTime{Time: c.Clock.Now()}
+	clone.Spec.PingTime = nil
+	_, err = c.LeaseClient.Update(ctx, clone, metav1.UpdateOptions{})
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *LeaseCandidate) newLease() *v1alpha1.LeaseCandidate {
+	lease := &v1alpha1.LeaseCandidate{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      c.name,
+			Namespace: c.namespace,
+		},
+		Spec: v1alpha1.LeaseCandidateSpec{
+			LeaseName:           c.leaseName,
+			BinaryVersion:       c.binaryVersion,
+			EmulationVersion:    c.emulationVersion,
+			PreferredStrategies: c.preferredStrategies,
+		},
+	}
+	lease.Spec.RenewTime = &metav1.MicroTime{Time: c.Clock.Now()}
+	return lease
+}

tools/leaderelection/leasecandidate_test.go

@@ -0,0 +1,146 @@
+/*
+Copyright 2024 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 leaderelection
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	v1 "k8s.io/api/coordination/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/kubernetes/fake"
+	"k8s.io/utils/clock"
+)
+
+type testcase struct {
+	candidateName, candidateNamespace, leaseName string
+	binaryVersion, emulationVersion              string
+}
+
+func TestLeaseCandidateCreation(t *testing.T) {
+	tc := testcase{
+		candidateName:      "foo",
+		candidateNamespace: "default",
+		leaseName:          "lease",
+		binaryVersion:      "1.30.0",
+		emulationVersion:   "1.30.0",
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+
+	client := fake.NewSimpleClientset()
+	candidate, err := NewCandidate(
+		client,
+		tc.candidateName,
+		tc.candidateNamespace,
+		tc.leaseName,
+		clock.RealClock{},
+		tc.binaryVersion,
+		tc.emulationVersion,
+		[]v1.CoordinatedLeaseStrategy{v1.OldestEmulationVersion},
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	go candidate.Run(ctx)
+	err = pollForLease(ctx, tc, client, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestLeaseCandidateAck(t *testing.T) {
+	tc := testcase{
+		candidateName:      "foo",
+		candidateNamespace: "default",
+		leaseName:          "lease",
+		binaryVersion:      "1.30.0",
+		emulationVersion:   "1.30.0",
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+
+	client := fake.NewSimpleClientset()
+
+	candidate, err := NewCandidate(
+		client,
+		tc.candidateName,
+		tc.candidateNamespace,
+		tc.leaseName,
+		clock.RealClock{},
+		tc.binaryVersion,
+		tc.emulationVersion,
+		[]v1.CoordinatedLeaseStrategy{v1.OldestEmulationVersion},
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	go candidate.Run(ctx)
+	err = pollForLease(ctx, tc, client, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Update PingTime and verify that the client renews
+	ensureAfter := &metav1.MicroTime{Time: time.Now()}
+	lc, err := client.CoordinationV1alpha1().LeaseCandidates(tc.candidateNamespace).Get(ctx, tc.candidateName, metav1.GetOptions{})
+	if err == nil {
+		if lc.Spec.PingTime == nil {
+			c := lc.DeepCopy()
+			c.Spec.PingTime = &metav1.MicroTime{Time: time.Now()}
+			_, err = client.CoordinationV1alpha1().LeaseCandidates(tc.candidateNamespace).Update(ctx, c, metav1.UpdateOptions{})
+			if err != nil {
+				t.Error(err)
+			}
+		}
+	}
+	err = pollForLease(ctx, tc, client, ensureAfter)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func pollForLease(ctx context.Context, tc testcase, client *fake.Clientset, t *metav1.MicroTime) error {
+	return wait.PollUntilContextTimeout(ctx, 100*time.Millisecond, 10*time.Second, true, func(ctx context.Context) (done bool, err error) {
+		lc, err := client.CoordinationV1alpha1().LeaseCandidates(tc.candidateNamespace).Get(ctx, tc.candidateName, metav1.GetOptions{})
+		if err != nil {
+			if errors.IsNotFound(err) {
+				return false, nil
+			}
+			return true, err
+		}
+		if lc.Spec.BinaryVersion == tc.binaryVersion &&
+			lc.Spec.EmulationVersion == tc.emulationVersion &&
+			lc.Spec.LeaseName == tc.leaseName &&
+			lc.Spec.PingTime == nil &&
+			lc.Spec.RenewTime != nil {
+			// Ensure that if a time is provided, the renewTime occurred after the provided time.
+			if t != nil && t.After(lc.Spec.RenewTime.Time) {
+				return false, nil
+			}
+			return true, nil
+		}
+		return false, nil
+	})
+}

tools/leaderelection/resourcelock/interface.go

@@ -19,14 +19,15 @@ package resourcelock
 import (
 	"context"
 	"fmt"
-	clientset "k8s.io/client-go/kubernetes"
-	restclient "k8s.io/client-go/rest"
 	"time"
 
+	v1 "k8s.io/api/coordination/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
+	clientset "k8s.io/client-go/kubernetes"
 	coordinationv1 "k8s.io/client-go/kubernetes/typed/coordination/v1"
 	corev1 "k8s.io/client-go/kubernetes/typed/core/v1"
+	restclient "k8s.io/client-go/rest"
 )
 
 const (
@@ -114,11 +115,13 @@ type LeaderElectionRecord struct {
 	// attempt to acquire leases with empty identities and will wait for the full lease
 	// interval to expire before attempting to reacquire. This value is set to empty when
 	// a client voluntarily steps down.
-	HolderIdentity       string      `json:"holderIdentity"`
-	LeaseDurationSeconds int         `json:"leaseDurationSeconds"`
-	AcquireTime          metav1.Time `json:"acquireTime"`
-	RenewTime            metav1.Time `json:"renewTime"`
-	LeaderTransitions    int         `json:"leaderTransitions"`
+	HolderIdentity       string                      `json:"holderIdentity"`
+	LeaseDurationSeconds int                         `json:"leaseDurationSeconds"`
+	AcquireTime          metav1.Time                 `json:"acquireTime"`
+	RenewTime            metav1.Time                 `json:"renewTime"`
+	LeaderTransitions    int                         `json:"leaderTransitions"`
+	Strategy             v1.CoordinatedLeaseStrategy `json:"strategy"`
+	PreferredHolder      string                      `json:"preferredHolder"`
 }
 
 // EventRecorder records a change in the ResourceLock.

tools/leaderelection/resourcelock/leaselock.go

@@ -122,6 +122,12 @@ func LeaseSpecToLeaderElectionRecord(spec *coordinationv1.LeaseSpec) *LeaderElec
 	if spec.RenewTime != nil {
 		r.RenewTime = metav1.Time{Time: spec.RenewTime.Time}
 	}
+	if spec.PreferredHolder != nil {
+		r.PreferredHolder = *spec.PreferredHolder
+	}
+	if spec.Strategy != nil {
+		r.Strategy = *spec.Strategy
+	}
 	return &r
 
 }
@@ -129,11 +135,18 @@ func LeaseSpecToLeaderElectionRecord(spec *coordinationv1.LeaseSpec) *LeaderElec
 func LeaderElectionRecordToLeaseSpec(ler *LeaderElectionRecord) coordinationv1.LeaseSpec {
 	leaseDurationSeconds := int32(ler.LeaseDurationSeconds)
 	leaseTransitions := int32(ler.LeaderTransitions)
-	return coordinationv1.LeaseSpec{
+	spec := coordinationv1.LeaseSpec{
 		HolderIdentity:       &ler.HolderIdentity,
 		LeaseDurationSeconds: &leaseDurationSeconds,
 		AcquireTime:          &metav1.MicroTime{Time: ler.AcquireTime.Time},
 		RenewTime:            &metav1.MicroTime{Time: ler.RenewTime.Time},
 		LeaseTransitions:     &leaseTransitions,
 	}
+	if ler.PreferredHolder != "" {
+		spec.PreferredHolder = &ler.PreferredHolder
+	}
+	if ler.Strategy != "" {
+		spec.Strategy = &ler.Strategy
+	}
+	return spec
 }