Merge pull request #29699 from timothysc/leader_jitter

Automatic merge from submit-queue

Update acquire to use newer JitterUntil vs. sleep 

Fix to prevent https://github.com/kubernetes/kubernetes/issues/26782 which could have had a race on a 0 timer the way it was written before due to changes in wait. 

I will likely make a PR for some of the recent changes in wait as well.

pkg/client/leaderelection/OWNERS

@@ -1,2 +1,3 @@
 assignees:
   - mikedanese
+  - timothysc

pkg/client/leaderelection/leaderelection.go

@@ -203,18 +203,17 @@ func (le *LeaderElector) IsLeader() bool {
 // acquire loops calling tryAcquireOrRenew and returns immediately when tryAcquireOrRenew succeeds.
 func (le *LeaderElector) acquire() {
 	stop := make(chan struct{})
-	wait.Until(func() {
+	wait.JitterUntil(func() {
 		succeeded := le.tryAcquireOrRenew()
 		le.maybeReportTransition()
 		if !succeeded {
 			glog.V(4).Infof("failed to renew lease %v/%v", le.config.EndpointsMeta.Namespace, le.config.EndpointsMeta.Name)
-			time.Sleep(wait.Jitter(le.config.RetryPeriod, JitterFactor))
 			return
 		}
 		le.config.EventRecorder.Eventf(&api.Endpoints{ObjectMeta: le.config.EndpointsMeta}, api.EventTypeNormal, "%v became leader", le.config.Identity)
 		glog.Infof("sucessfully acquired lease %v/%v", le.config.EndpointsMeta.Namespace, le.config.EndpointsMeta.Name)
 		close(stop)
-	}, 0, stop)
+	}, le.config.RetryPeriod, JitterFactor, true, stop)
 }
 
 // renew loops calling tryAcquireOrRenew and returns immediately when tryAcquireOrRenew fails.