feedback: leasecandidate clients

Kubernetes-commit: fac758164029e278e9bda924090ed078bb6514c8

tools/leaderelection/leaderelection.go

@@ -161,6 +161,7 @@ type LeaderElectionConfig struct {
  Name string
 
  // Coordinated will use the Coordinated Leader Election feature
+ // WARNING: Coordinated leader election is ALPHA.
  Coordinated bool
 }
 
@@ -293,6 +294,7 @@ 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())
 
@@ -354,23 +356,23 @@ func (le *LeaderElector) tryCoordinatedRenew(ctx context.Context) bool {
 
  le.observedRawRecord = oldLeaderElectionRawRecord
  }
- hasExpired := le.observedTime.Add(time.Second * time.Duration(oldLeaderElectionRecord.LeaseDurationSeconds)).Before(now.Time)
 
+ 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())
+ klog.V(6).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..
+ // 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.

tools/leaderelection/leasecandidate.go

@@ -63,9 +63,14 @@ type LeaseCandidate struct {
  preferredStrategies []v1.CoordinatedLeaseStrategy
 }
 
+// NewCandidate creates new LeaseCandidate controller that creates a
+// LeaseCandidate object if it does not exist and watches changes
+// to the corresponding object and renews if PingTime is set.
+// WARNING: This is an ALPHA feature. Ensure that the CoordinatedLeaderElection
+// feature gate is on.
 func NewCandidate(clientset kubernetes.Interface,
- candidateName string,
  candidateNamespace string,
+ candidateName string,
  targetLease string,
  binaryVersion, emulationVersion string,
  preferredStrategies []v1.CoordinatedLeaseStrategy,
@@ -144,7 +149,6 @@ func (c *LeaseCandidate) processNextWorkItem(ctx context.Context) bool {
  }
 
  utilruntime.HandleError(err)
- klog.Infof("processNextWorkItem.AddRateLimited: %v", key)
  c.queue.AddRateLimited(key)
 
  return true
@@ -161,17 +165,16 @@ func (c *LeaseCandidate) ensureLease(ctx context.Context) error {
  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 {
+ leaseToCreate := c.newLeaseCandidate()
+ if _, err := c.leaseClient.Create(ctx, leaseToCreate, metav1.CreateOptions{}); 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")
+ klog.V(2).Infof("lease candidate exists. Renewing.")
  clone := lease.DeepCopy()
  clone.Spec.RenewTime = &metav1.MicroTime{Time: c.clock.Now()}
  clone.Spec.PingTime = nil
@@ -182,8 +185,8 @@ func (c *LeaseCandidate) ensureLease(ctx context.Context) error {
  return nil
 }
 
-func (c *LeaseCandidate) newLease() *v1alpha1.LeaseCandidate {
- lease := &v1alpha1.LeaseCandidate{
+func (c *LeaseCandidate) newLeaseCandidate() *v1alpha1.LeaseCandidate {
+ lc := &v1alpha1.LeaseCandidate{
  ObjectMeta: metav1.ObjectMeta{
  Name: c.name,
  Namespace: c.namespace,
@@ -195,6 +198,6 @@ func (c *LeaseCandidate) newLease() *v1alpha1.LeaseCandidate {
  PreferredStrategies: c.preferredStrategies,
  },
  }
- lease.Spec.RenewTime = &metav1.MicroTime{Time: c.clock.Now()}
- return lease
+ lc.Spec.RenewTime = &metav1.MicroTime{Time: c.clock.Now()}
+ return lc
 }

tools/leaderelection/leasecandidate_test.go

@@ -48,8 +48,8 @@ func TestLeaseCandidateCreation(t *testing.T) {
  client := fake.NewSimpleClientset()
  candidate, _, err := NewCandidate(
  client,
- tc.candidateName,
  tc.candidateNamespace,
+ tc.candidateName,
  tc.leaseName,
  tc.binaryVersion,
  tc.emulationVersion,