type defaultLeaderMetrics struct {
	// leader's value indicates if the current process is the owner of name lease
	leader SwitchMetric
}

func (m *defaultLeaderMetrics) leaderOn(name string) {
	if m == nil {
		return
	}
	m.leader.On(name)
}

func (m *defaultLeaderMetrics) leaderOff(name string) {
	if m == nil {
		return
	}
	m.leader.Off(name)
}

type noMetrics struct{}

	OnStoppedLeading func()
	// OnNewLeader is called when the client observes a leader that is
	// not the previously observed leader. This includes the first observed
	// leader when the client starts.
	OnNewLeader func(identity string)
}

// LeaderElector is a leader election client.
type LeaderElector struct {
	config LeaderElectionConfig
	// internal bookkeeping

apiVersion: release-notes/v2
kind: bug-fix
area: traffic-management
issue:
- 47901
releaseNotes:
- |

docs:
 - '[reference] https://istio.io/latest/docs/reference/commands/pilot-discovery/'

releaseNotes:
- |
  **Added** an `ENABLE_LEADER_ELECTION=false` feature flag for pilot-discovery

		if mls != nil && mls.IsLeader(n) {
			leaders[n] = -s.stksize
		}
	}

	if mls != nil {
		// Update offsets of followers (subsumed vars) to be the
		// same as the leader var in their partition.
		for i := 0; i < len(fn.Dcl); i++ {
			n := fn.Dcl[i]
			if !mls.Subsumed(n) {
				continue
			}
			leader := mls.Leader(n)
			off, ok := leaders[leader]
			if !ok {

	// Store as field for testing
	le *k8sleaderelection.LeaderElector
	mu sync.RWMutex
}

// Run will start leader election, calling all runFns when we become the leader.
// If leader election is disabled, it skips straight to the runFns.
func (l *LeaderElection) Run(stop <-chan struct{}) {
	if !l.enabled {
		log.Infof("bypassing leader election: %v", l.electionID)
		for _, f := range l.runFns {
			go f(stop)
		}
		<-stop
		return
	}

  case "${KUBE_CONTROLLER_MANAGER_LEADER}" in
  "")
    log ERR "No leader election info found."
    return 1
    ;;

  "${HOSTNAME}"_*)
    log INFO "Leader is $KUBE_CONTROLLER_MANAGER_LEADER"
    return 0
    ;;

  *)
    log INFO "Leader is $KUBE_CONTROLLER_MANAGER_LEADER, not ${HOSTNAME}_*"
    return 1
    ;;
  esac

				ContentType: "application/vnd.kubernetes.protobuf",
				QPS:         50,
				Burst:       100,
			},
		},
		{
			name: "leader election CLI args, without --config arg",
			flags: []string{
				"--leader-elect=false",
				"--leader-elect-lease-duration=2h",
				"--leader-elect-resource-namespace=default",
				"--kubeconfig", configKubeconfig, // deprecated CLI arg is honored if --config is not specified
			},

// It helps deal with the /healthz endpoint being set up prior to the LeaderElection.
// This contains the code needed to act as an adaptor between the leader
// election code the health check code. It allows us to provide health
// status about the leader election. Most specifically about if the leader
// has failed to renew without exiting the process. In that case we should
// report not healthy and rely on the kubelet to take down the process.

	leaderelection := o.Flags.FlagSet("leader election")
	if leaderelection.Changed("leader-elect") {
		cfg.LeaderElection.LeaderElect = o.LeaderElection.LeaderElect
	}
	if leaderelection.Changed("leader-elect-lease-duration") {
		cfg.LeaderElection.LeaseDuration = o.LeaderElection.LeaseDuration
	}
	if leaderelection.Changed("leader-elect-renew-deadline") {