leasecandidate: Improve goroutine management

Make sure all goroutines are terminated when Run returns.

Kubernetes-commit: 498896ec4270b790e971a6fb01a292aa4c8cdfe0

tools/leaderelection/leasecandidate.go

@@ -19,6 +19,7 @@ package leaderelection
 import (
 	"context"
 	"reflect"
+	"sync"
 	"time"
 
 	v1 "k8s.io/api/coordination/v1"
@@ -118,19 +119,25 @@ func NewCandidate(clientset kubernetes.Interface,
 }
 
 func (c *LeaseCandidate) Run(ctx context.Context) {
-	defer c.queue.ShutDown()
-
 	logger := klog.FromContext(ctx)
 	logger = klog.LoggerWithName(logger, "leasecandidate")
 	ctx = klog.NewContext(ctx, logger)
 
+	var wg sync.WaitGroup
+	defer func() {
+		c.queue.ShutDown()
+		wg.Wait()
+	}()
+
 	c.informerFactory.Start(ctx.Done())
 	if !cache.WaitForNamedCacheSyncWithContext(ctx, c.hasSynced) {
 		return
 	}
 
 	c.enqueueLease()
-	go c.runWorker(ctx)
+	wg.Go(func() {
+		c.runWorker(ctx)
+	})
 	<-ctx.Done()
 }