leaderelection: use 'leases' as default resource lock object

Signed-off-by: Joe Lanford <joe.lanford@gmail.com>

pkg/leaderelection/leader_election.go

@@ -27,6 +27,7 @@ import (
 	corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/leaderelection/resourcelock"
+
 	"sigs.k8s.io/controller-runtime/pkg/recorder"
 )
 
@@ -39,7 +40,7 @@ type Options struct {
 	LeaderElection bool
 
 	// LeaderElectionResourceLock determines which resource lock to use for leader election,
-	// defaults to "configmapsleases".
+	// defaults to "leases".
 	LeaderElectionResourceLock string
 
 	// LeaderElectionNamespace determines the namespace in which the leader
@@ -57,11 +58,12 @@ func NewResourceLock(config *rest.Config, recorderProvider recorder.Provider, op
 		return nil, nil
 	}
 
-	// Default resource lock to "configmapsleases". We must keep this default until we are sure all controller-runtime
-	// users have upgraded from the original default ConfigMap lock to a controller-runtime version that has this new
-	// default. Many users of controller-runtime skip versions, so we should be extremely conservative here.
+	// Default resource lock to "leases". The previous default (from v0.7.0 to v0.11.x) was configmapsleases, which was
+	// used to migrate from configmaps to leases. Since the default was "configmapsleases" for over a year, spanning
+	// five minor releases, any actively maintained operators are very likely to have a released version that uses
+	// "configmapsleases". Therefore defaulting to "leases" should be safe.
 	if options.LeaderElectionResourceLock == "" {
-		options.LeaderElectionResourceLock = resourcelock.ConfigMapsLeasesResourceLock
+		options.LeaderElectionResourceLock = resourcelock.LeasesResourceLock
 	}
 
 	// LeaderElectionID must be provided to prevent clashes