Remove legacy leader election

ref: https://issues.redhat.com/browse/ACM-5042
Signed-off-by: Dale Haiducek <[email protected]>

Author: dhaiducek

main.go

@@ -219,16 +219,6 @@ func main() {
 		),
 	}
 
-	if tool.Options.LegacyLeaderElection {
-		// If legacyLeaderElection is enabled, then that means the lease API is not available.
-		// In this case, use the legacy leader election method of a ConfigMap.
-		mgrOptionsBase.LeaderElectionResourceLock = "configmaps"
-	} else {
-		// use the leases leader election by default for controller-runtime 0.11 instead of
-		// the default of configmapsleases (leases is the new default in 0.12)
-		mgrOptionsBase.LeaderElectionResourceLock = "leases"
-	}
-
 	// This lease is not related to leader election. This is to report the status of the controller
 	// to the addon framework. This can be seen in the "status" section of the ManagedClusterAddOn
 	// resource objects.

tool/options.go

@@ -21,7 +21,6 @@ type SyncerOptions struct {
 	DisableGkSync             bool
 	EnableLease               bool
 	EnableLeaderElection      bool
-	LegacyLeaderElection      bool
 	ProbeAddr                 string
 	MetricsAddr               string
 	// The namespace that the replicated policies should be synced to. This defaults to the same namespace as on the
@@ -94,13 +93,6 @@ func ProcessFlags() {
 			"Enabling this will ensure there is only one active controller manager.",
 	)
 
-	flag.BoolVar(
-		&Options.LegacyLeaderElection,
-		"legacy-leader-elect",
-		false,
-		"Use a legacy leader election method for controller manager instead of the lease API.",
-	)
-
 	flag.StringVar(
 		&Options.ProbeAddr,
 		"health-probe-bind-address",