Add lock type flags for controller-manager leadership election

cmd/kube-controller-manager/app/controllermanager.go

@@ -32,7 +32,6 @@ import (
 	"strconv"
 	"time"
 
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/wait"
@@ -192,21 +191,17 @@ func Run(s *options.CMServer) error {
 		return err
 	}
 
-	// TODO: enable other lock types
-	rl := resourcelock.EndpointsLock{
-		EndpointsMeta: metav1.ObjectMeta{
-			Namespace: "kube-system",
-			Name:      "kube-controller-manager",
-		},
-		Client: leaderElectionClient,
-		LockConfig: resourcelock.ResourceLockConfig{
-			Identity:      id,
-			EventRecorder: recorder,
-		},
+	rlc := resourcelock.ResourceLockConfig{
+		Identity:      id,
+		EventRecorder: recorder,
+	}
+	rl, err := leaderelection.GetLock(s.LeaderElection, *leaderElectionClient, rlc)
+	if err != nil {
+		return err
 	}
 
 	leaderelection.RunOrDie(leaderelection.LeaderElectionConfig{
-		Lock:          &rl,
+		Lock:          rl,
 		LeaseDuration: s.LeaderElection.LeaseDuration.Duration,
 		RenewDeadline: s.LeaderElection.RenewDeadline.Duration,
 		RetryPeriod:   s.LeaderElection.RetryPeriod.Duration,

pkg/apis/componentconfig/types.go

@@ -685,6 +685,9 @@ type LeaderElectionConfiguration struct {
 	// acquisition and renewal of a leadership. This is only applicable if
 	// leader election is enabled.
 	RetryPeriod metav1.Duration
+	// LockType indicates the type of locking to use for leadership election.
+	// Supported options are `endpoints` (default) and `configmap`.
+	LockType string
 }
 
 type KubeControllerManagerConfiguration struct {

pkg/apis/componentconfig/v1alpha1/types.go

@@ -233,6 +233,9 @@ type LeaderElectionConfiguration struct {
 	// acquisition and renewal of a leadership. This is only applicable if
 	// leader election is enabled.
 	RetryPeriod metav1.Duration `json:"retryPeriod"`
+	// LockType indicates the type of locking to use for leadership election.
+	// Supported options are `endpoints` (default) and `configmap`.
+	LockType string
 }
 
 // A configuration field should go in KubeletFlags instead of KubeletConfiguration if any of these are true:

pkg/apis/componentconfig/v1alpha1/zz_generated.conversion.go

@@ -814,6 +814,7 @@ func autoConvert_v1alpha1_LeaderElectionConfiguration_To_componentconfig_LeaderE
 	out.LeaseDuration = in.LeaseDuration
 	out.RenewDeadline = in.RenewDeadline
 	out.RetryPeriod = in.RetryPeriod
+	out.LockType = in.LockType
 	return nil
 }
 
@@ -829,6 +830,7 @@ func autoConvert_componentconfig_LeaderElectionConfiguration_To_v1alpha1_LeaderE
 	out.LeaseDuration = in.LeaseDuration
 	out.RenewDeadline = in.RenewDeadline
 	out.RetryPeriod = in.RetryPeriod
+	out.LockType = in.LockType
 	return nil
 }
 

pkg/client/leaderelection/BUILD

@@ -14,6 +14,7 @@ go_library(
     tags = ["automanaged"],
     deps = [
         "//pkg/apis/componentconfig:go_default_library",
+        "//pkg/client/clientset_generated/clientset:go_default_library",
         "//pkg/client/leaderelection/resourcelock:go_default_library",
         "//vendor/github.com/golang/glog:go_default_library",
         "//vendor/github.com/spf13/pflag:go_default_library",

pkg/client/leaderelection/leaderelection.go

@@ -53,11 +53,12 @@ import (
 	"reflect"
 	"time"
 
-	"k8s.io/apimachinery/pkg/api/errors"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/kubernetes/pkg/apis/componentconfig"
+	cs "k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
 	rl "k8s.io/kubernetes/pkg/client/leaderelection/resourcelock"
 
 	"github.com/golang/glog"
@@ -69,6 +70,9 @@ const (
 	DefaultLeaseDuration = 15 * time.Second
 	DefaultRenewDeadline = 10 * time.Second
 	DefaultRetryPeriod   = 2 * time.Second
+
+	LockTypeEndpoints  = "endpoints"
+	LockTypeConfigMaps = "configmaps"
 )
 
 // NewLeadereElector creates a LeaderElector from a LeaderElecitionConfig
@@ -225,7 +229,7 @@ func (le *LeaderElector) tryAcquireOrRenew() bool {
 	// 1. obtain or create the ElectionRecord
 	oldLeaderElectionRecord, err := le.config.Lock.Get()
 	if err != nil {
-		if !errors.IsNotFound(err) {
+		if !apierrors.IsNotFound(err) {
 			glog.Errorf("error retrieving resource lock %v: %v", le.config.Lock.Describe(), err)
 			return false
 		}
@@ -284,6 +288,7 @@ func DefaultLeaderElectionConfiguration() componentconfig.LeaderElectionConfigur
 		LeaseDuration: metav1.Duration{Duration: DefaultLeaseDuration},
 		RenewDeadline: metav1.Duration{Duration: DefaultRenewDeadline},
 		RetryPeriod:   metav1.Duration{Duration: DefaultRetryPeriod},
+		LockType:      LockTypeEndpoints,
 	}
 }
 
@@ -306,4 +311,33 @@ func BindFlags(l *componentconfig.LeaderElectionConfiguration, fs *pflag.FlagSet
 	fs.DurationVar(&l.RetryPeriod.Duration, "leader-elect-retry-period", l.RetryPeriod.Duration, ""+
 		"The duration the clients should wait between attempting acquisition and renewal "+
 		"of a leadership. This is only applicable if leader election is enabled.")
+	fs.StringVar(&l.LockType, "leader-elect-lock-type", l.LockType, fmt.Sprintf(""+
+		"Indicates the type of locking to use for leadership election. Supported options "+
+		"are `%s` (default) and `%s`.", LockTypeConfigMaps, LockTypeEndpoints))
+}
+
+func GetLock(l componentconfig.LeaderElectionConfiguration, client cs.Clientset, rlc rl.ResourceLockConfig) (rl.Interface, error) {
+	name := "kube-controller-manager"
+	switch l.LockType {
+	case LockTypeEndpoints:
+		return &rl.EndpointsLock{
+			EndpointsMeta: metav1.ObjectMeta{
+				Namespace: metav1.NamespaceSystem,
+				Name:      name,
+			},
+			Client:     client,
+			LockConfig: rlc,
+		}, nil
+	case LockTypeConfigMaps:
+		return &rl.ConfigMapLock{
+			ConfigMapMeta: metav1.ObjectMeta{
+				Namespace: metav1.NamespaceSystem,
+				Name:      name,
+			},
+			Client:     client,
+			LockConfig: rlc,
+		}, nil
+	default:
+		return nil, fmt.Errorf("Invalid lock-type provided: %s. Supported types are `%s` and `%s`", l.LockType, LockTypeConfigMaps, LockTypeEndpoints)
+	}
 }