feat: using LeaseLock for election (#8921)

We removed the use of configmap as an election lock, so we will use the
Lease API to complete the election.

Before this, we used `MultiLock` to facilitate smooth migration of
existing users of ingress-nginx from configmap to LeaseLock.

Signed-off-by: Jintao Zhang <zhangjintao9020@gmail.com>

Signed-off-by: Jintao Zhang <zhangjintao9020@gmail.com>

charts/ingress-nginx/templates/controller-role.yaml

@@ -58,21 +58,6 @@ rules:
       - get
       - list
       - watch
-  - apiGroups:
-      - ""
-    resources:
-      - configmaps
-    resourceNames:
-      - {{ .Values.controller.electionID }}
-    verbs:
-      - get
-      - update
-  - apiGroups:
-      - ""
-    resources:
-      - configmaps
-    verbs:
-      - create
   - apiGroups:
       - coordination.k8s.io
     resources:

internal/ingress/controller/status.go

@@ -99,25 +99,16 @@ func setupLeaderElection(config *leaderElectionConfig) {
 		EventRecorder: recorder,
 	}
 
-	// TODO: If we upgrade client-go to v0.24 then we can only use LeaseLock.
-	// MultiLock is used for lock's migration
-	lock := resourcelock.MultiLock{
-		Primary: &resourcelock.ConfigMapLock{
-			ConfigMapMeta: objectMeta,
-			Client:        config.Client.CoreV1(),
-			LockConfig:    resourceLockConfig,
-		},
-		Secondary: &resourcelock.LeaseLock{
-			LeaseMeta:  objectMeta,
-			Client:     config.Client.CoordinationV1(),
-			LockConfig: resourceLockConfig,
-		},
+	lock := &resourcelock.LeaseLock{
+		LeaseMeta:  objectMeta,
+		Client:     config.Client.CoordinationV1(),
+		LockConfig: resourceLockConfig,
 	}
 
 	ttl := 30 * time.Second
 
 	elector, err := leaderelection.NewLeaderElector(leaderelection.LeaderElectionConfig{
-		Lock:          &lock,
+		Lock:          lock,
 		LeaseDuration: ttl,
 		RenewDeadline: ttl / 2,
 		RetryPeriod:   ttl / 4,

test/e2e/status/update.go

@@ -92,10 +92,10 @@ var _ = framework.IngressNginxDescribe("[Status] status update", func() {
 		assert.Nil(ginkgo.GinkgoT(), err, "unexpected error cleaning Ingress status")
 		framework.Sleep(10 * time.Second)
 
-		err = f.KubeClientSet.CoreV1().
-			ConfigMaps(f.Namespace).
+		err = f.KubeClientSet.CoordinationV1().
+			Leases(f.Namespace).
 			Delete(context.TODO(), "ingress-controller-leader", metav1.DeleteOptions{})
-		assert.Nil(ginkgo.GinkgoT(), err, "unexpected error deleting leader election configmap")
+		assert.Nil(ginkgo.GinkgoT(), err, "unexpected error deleting leader election lease")
 
 		_, cmd, err = f.KubectlProxy(port)
 		assert.Nil(ginkgo.GinkgoT(), err, "unexpected error starting kubectl proxy")