leader election: remove obsolete ConfigMapsResourceLock and EndpointsResourceLock

Kubernetes 1.24 won't support those anymore. To support building with a newer
client-go, csi-lib-utils must not reference the removed constants. This doesn't
affect the sidecars because those only use the default NewLeaderElection.

Author: pohly

leaderelection/leader_election.go

@@ -61,8 +61,7 @@ type leaderElection struct {
 	// the namespace to store the lock resource
 	namespace string
 	// resourceLock defines the type of leaderelection that should be used
-	// valid options are resourcelock.LeasesResourceLock, resourcelock.EndpointsResourceLock,
-	// and resourcelock.ConfigMapsResourceLock
+	// Only resourcelock.LeasesResourceLock is valid at the moment.
 	resourceLock string
 	// healthCheck reports unhealthy if leader election fails to renew leadership
 	// within a timeout period.
@@ -95,32 +94,6 @@ func NewLeaderElectionWithLeases(clientset kubernetes.Interface, lockName string
 	}
 }
 
-// NewLeaderElectionWithEndpoints returns an implementation of leader election using Endpoints
-func NewLeaderElectionWithEndpoints(clientset kubernetes.Interface, lockName string, runFunc func(ctx context.Context)) *leaderElection {
-	return &leaderElection{
-		runFunc:       runFunc,
-		lockName:      lockName,
-		resourceLock:  resourcelock.EndpointsResourceLock,
-		leaseDuration: defaultLeaseDuration,
-		renewDeadline: defaultRenewDeadline,
-		retryPeriod:   defaultRetryPeriod,
-		clientset:     clientset,
-	}
-}
-
-// NewLeaderElectionWithConfigMaps returns an implementation of leader election using ConfigMaps
-func NewLeaderElectionWithConfigMaps(clientset kubernetes.Interface, lockName string, runFunc func(ctx context.Context)) *leaderElection {
-	return &leaderElection{
-		runFunc:       runFunc,
-		lockName:      lockName,
-		resourceLock:  resourcelock.ConfigMapsResourceLock,
-		leaseDuration: defaultLeaseDuration,
-		renewDeadline: defaultRenewDeadline,
-		retryPeriod:   defaultRetryPeriod,
-		clientset:     clientset,
-	}
-}
-
 func (l *leaderElection) WithIdentity(identity string) {
 	l.identity = identity
 }