[Kube-scheduler] Lower timeout for leaderelection resourcelock

Migrate how resource lock and leader election config is generated to new
way, hidding kubeClient. This also halfs kubeClient timeout, making it
an useful value.

cmd/kube-scheduler/app/options/options.go

@@ -266,8 +266,14 @@ func (o *Options) Config() (*schedulerappconfig.Config, error) {
 		return nil, err
 	}
 
+	// Prepare kube config.
+	kubeConfig, err := createKubeConfig(c.ComponentConfig.ClientConnection, o.Master)
+	if err != nil {
+		return nil, err
+	}
+
 	// Prepare kube clients.
-	client, leaderElectionClient, eventClient, err := createClients(c.ComponentConfig.ClientConnection, o.Master, c.ComponentConfig.LeaderElection.RenewDeadline.Duration)
+	client, eventClient, err := createClients(kubeConfig)
 	if err != nil {
 		return nil, err
 	}
@@ -279,7 +285,7 @@ func (o *Options) Config() (*schedulerappconfig.Config, error) {
 	if c.ComponentConfig.LeaderElection.LeaderElect {
 		// Use the scheduler name in the first profile to record leader election.
 		coreRecorder := c.EventBroadcaster.DeprecatedNewLegacyRecorder(c.ComponentConfig.Profiles[0].SchedulerName)
-		leaderElectionConfig, err = makeLeaderElectionConfig(c.ComponentConfig.LeaderElection, leaderElectionClient, coreRecorder)
+		leaderElectionConfig, err = makeLeaderElectionConfig(c.ComponentConfig.LeaderElection, kubeConfig, coreRecorder)
 		if err != nil {
 			return nil, err
 		}
@@ -294,7 +300,7 @@ func (o *Options) Config() (*schedulerappconfig.Config, error) {
 
 // makeLeaderElectionConfig builds a leader election configuration. It will
 // create a new resource lock associated with the configuration.
-func makeLeaderElectionConfig(config componentbaseconfig.LeaderElectionConfiguration, client clientset.Interface, recorder record.EventRecorder) (*leaderelection.LeaderElectionConfig, error) {
+func makeLeaderElectionConfig(config componentbaseconfig.LeaderElectionConfiguration, kubeConfig *restclient.Config, recorder record.EventRecorder) (*leaderelection.LeaderElectionConfig, error) {
 	hostname, err := os.Hostname()
 	if err != nil {
 		return nil, fmt.Errorf("unable to get hostname: %v", err)
@@ -302,15 +308,15 @@ func makeLeaderElectionConfig(config componentbaseconfig.LeaderElectionConfigura
 	// add a uniquifier so that two processes on the same host don't accidentally both become active
 	id := hostname + "_" + string(uuid.NewUUID())
 
-	rl, err := resourcelock.New(config.ResourceLock,
+	rl, err := resourcelock.NewFromKubeconfig(config.ResourceLock,
 		config.ResourceNamespace,
 		config.ResourceName,
-		client.CoreV1(),
-		client.CoordinationV1(),
 		resourcelock.ResourceLockConfig{
 			Identity:      id,
 			EventRecorder: recorder,
-		})
+		},
+		kubeConfig,
+		config.RenewDeadline.Duration)
 	if err != nil {
 		return nil, fmt.Errorf("couldn't create resource lock: %v", err)
 	}
@@ -325,9 +331,9 @@ func makeLeaderElectionConfig(config componentbaseconfig.LeaderElectionConfigura
 	}, nil
 }
 
-// createClients creates a kube client and an event client from the given config and masterOverride.
+// createKubeConfig creates a kubeConfig from the given config and masterOverride.
 // TODO remove masterOverride when CLI flags are removed.
-func createClients(config componentbaseconfig.ClientConnectionConfiguration, masterOverride string, timeout time.Duration) (clientset.Interface, clientset.Interface, clientset.Interface, error) {
+func createKubeConfig(config componentbaseconfig.ClientConnectionConfiguration, masterOverride string) (*restclient.Config, error) {
 	if len(config.Kubeconfig) == 0 && len(masterOverride) == 0 {
 		klog.Warningf("Neither --kubeconfig nor --master was specified. Using default API client. This might not work.")
 	}
@@ -338,7 +344,7 @@ func createClients(config componentbaseconfig.ClientConnectionConfiguration, mas
 		&clientcmd.ClientConfigLoadingRules{ExplicitPath: config.Kubeconfig},
 		&clientcmd.ConfigOverrides{ClusterInfo: clientcmdapi.Cluster{Server: masterOverride}}).ClientConfig()
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, err
 	}
 
 	kubeConfig.DisableCompression = true
@@ -347,23 +353,20 @@ func createClients(config componentbaseconfig.ClientConnectionConfiguration, mas
 	kubeConfig.QPS = config.QPS
 	kubeConfig.Burst = int(config.Burst)
 
+	return kubeConfig, nil
+}
+
+// createClients creates a kube client and an event client from the given kubeConfig
+func createClients(kubeConfig *restclient.Config) (clientset.Interface, clientset.Interface, error) {
 	client, err := clientset.NewForConfig(restclient.AddUserAgent(kubeConfig, "scheduler"))
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, err
-	}
-
-	// shallow copy, do not modify the kubeConfig.Timeout.
-	restConfig := *kubeConfig
-	restConfig.Timeout = timeout
-	leaderElectionClient, err := clientset.NewForConfig(restclient.AddUserAgent(&restConfig, "leader-election"))
-	if err != nil {
-		return nil, nil, nil, err
 	}
 
 	eventClient, err := clientset.NewForConfig(kubeConfig)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, err
 	}
 
-	return client, leaderElectionClient, eventClient, nil
+	return client, eventClient, nil
 }