Merge pull request #136435 from Jefftree/leaderelection-client-efficiency

Update leasecandidate client to read from cache

Kubernetes-commit: 4e3e58ffbe28674a5125cff183e8dacf97b07775

tools/leaderelection/leasecandidate.go

@@ -35,6 +35,8 @@ import (
 	"k8s.io/client-go/util/workqueue"
 	"k8s.io/klog/v2"
 	"k8s.io/utils/clock"
+
+	coordinationv1beta1listers "k8s.io/client-go/listers/coordination/v1beta1"
 )
 
 const requeueInterval = 5 * time.Minute
@@ -46,6 +48,7 @@ type CacheSyncWaiter interface {
 type LeaseCandidate struct {
 	leaseClient            coordinationv1beta1client.LeaseCandidateInterface
 	leaseCandidateInformer cache.SharedIndexInformer
+	leaseCandidateLister   coordinationv1beta1listers.LeaseCandidateLister
 	informerFactory        informers.SharedInformerFactory
 	hasSynced              cache.InformerSynced
 
@@ -81,15 +84,18 @@ func NewCandidate(clientset kubernetes.Interface,
 	// are started for leader elected components
 	informerFactory := informers.NewSharedInformerFactoryWithOptions(
 		clientset, 5*time.Minute,
+		informers.WithNamespace(candidateNamespace),
 		informers.WithTweakListOptions(func(options *metav1.ListOptions) {
 			options.FieldSelector = fieldSelector
 		}),
 	)
 	leaseCandidateInformer := informerFactory.Coordination().V1beta1().LeaseCandidates().Informer()
+	leaseCandidateLister := informerFactory.Coordination().V1beta1().LeaseCandidates().Lister()
 
 	lc := &LeaseCandidate{
 		leaseClient:            clientset.CoordinationV1beta1().LeaseCandidates(candidateNamespace),
 		leaseCandidateInformer: leaseCandidateInformer,
+		leaseCandidateLister:   leaseCandidateLister,
 		informerFactory:        informerFactory,
 		name:                   candidateName,
 		namespace:              candidateNamespace,
@@ -173,7 +179,7 @@ func (c *LeaseCandidate) enqueueLease() {
 // a bool (true if this call created the lease), or any error that occurs.
 func (c *LeaseCandidate) ensureLease(ctx context.Context) error {
 	logger := klog.FromContext(ctx)
-	lease, err := c.leaseClient.Get(ctx, c.name, metav1.GetOptions{})
+	lease, err := c.leaseCandidateLister.LeaseCandidates(c.namespace).Get(c.name)
 	if apierrors.IsNotFound(err) {
 		logger.V(2).Info("Creating lease candidate")
 		// lease does not exist, create it.