Merge pull request #45739 from timothysc/cm_lock

Automatic merge from submit-queue (batch tested with PRs 45374, 44537, 45739, 44474, 45888)

Allow kcm and scheduler to lock on ConfigMaps.

**What this PR does / why we need it**:
Plumbs through the ability to lock on ConfigMaps through the kcm and scheduler.  

**Which issue this PR fixes** 
Fixes: #44857
Addresses issues with: #45415

**Special notes for your reviewer**:

**Release note**:

```
Add leader-election-resource-lock support to kcm and scheduler to allow for locking on ConfigMaps as well as Endpoints(default) 
```
/cc @kubernetes/sig-cluster-lifecycle-pr-reviews @jamiehannaford @bsalamat @mikedanese

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 +191,20 @@ 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{
+	rl, err := resourcelock.New(s.LeaderElection.ResourceLock,
+		"kube-system",
+		"kube-controller-manager",
+		leaderElectionClient,
+		resourcelock.ResourceLockConfig{
 			Identity:      id,
 			EventRecorder: recorder,
-		},
+		})
+	if err != nil {
+		glog.Fatalf("error creating lock: %v", err)
 	}
 
 	leaderelection.RunOrDie(leaderelection.LeaderElectionConfig{
-		Lock:          &rl,
+		Lock:          rl,
 		LeaseDuration: s.LeaderElection.LeaseDuration.Duration,
 		RenewDeadline: s.LeaderElection.RenewDeadline.Duration,
 		RetryPeriod:   s.LeaderElection.RetryPeriod.Duration,

hack/verify-flags/known-flags.txt

@@ -425,7 +425,9 @@ large-cluster-size-threshold
 last-release-pr
 leader-elect
 leader-elect-lease-duration
+leader-elect-lock-type
 leader-elect-renew-deadline
+leader-elect-resource-lock
 leader-elect-retry-period
 lease-duration
 leave-stdin-open

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
+	// resourceLock indicates the resource object type that will be used to lock
+	// during leader election cycles.
+	ResourceLock string
 }
 
 type KubeControllerManagerConfiguration struct {

pkg/apis/componentconfig/v1alpha1/BUILD

@@ -24,6 +24,7 @@ go_library(
         "//pkg/api:go_default_library",
         "//pkg/api/v1:go_default_library",
         "//pkg/apis/componentconfig:go_default_library",
+        "//pkg/client/leaderelection/resourcelock:go_default_library",
         "//pkg/kubelet/qos:go_default_library",
         "//pkg/kubelet/types:go_default_library",
         "//pkg/master/ports:go_default_library",

pkg/apis/componentconfig/v1alpha1/defaults.go

@@ -26,6 +26,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	kruntime "k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/kubernetes/pkg/api"
+	rl "k8s.io/kubernetes/pkg/client/leaderelection/resourcelock"
 	"k8s.io/kubernetes/pkg/kubelet/qos"
 	kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
 	"k8s.io/kubernetes/pkg/master/ports"
@@ -193,6 +194,9 @@ func SetDefaults_LeaderElectionConfiguration(obj *LeaderElectionConfiguration) {
 	if obj.RetryPeriod == zero {
 		obj.RetryPeriod = metav1.Duration{Duration: 2 * time.Second}
 	}
+	if obj.ResourceLock == "" {
+		obj.ResourceLock = rl.EndpointsResourceLock
+	}
 }
 
 func SetDefaults_KubeletConfiguration(obj *KubeletConfiguration) {

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"`
+	// resourceLock indicates the resource object type that will be used to lock
+	// during leader election cycles.
+	ResourceLock string `json:"resourceLock"`
 }
 
 // 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.ResourceLock = in.ResourceLock
 	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.ResourceLock = in.ResourceLock
 	return nil
 }
 

pkg/client/leaderelection/leaderelection.go

@@ -284,6 +284,7 @@ func DefaultLeaderElectionConfiguration() componentconfig.LeaderElectionConfigur
 		LeaseDuration: metav1.Duration{Duration: DefaultLeaseDuration},
 		RenewDeadline: metav1.Duration{Duration: DefaultRenewDeadline},
 		RetryPeriod:   metav1.Duration{Duration: DefaultRetryPeriod},
+		ResourceLock:  rl.EndpointsResourceLock,
 	}
 }
 
@@ -306,4 +307,7 @@ 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.ResourceLock, "leader-elect-resource-lock", l.ResourceLock, ""+
+		"The type of resource resource object that is used for locking during"+
+		"leader election. Supported options are `endpoints` (default) and `configmap`.")
 }

pkg/client/leaderelection/resourcelock/BUILD

@@ -17,6 +17,7 @@ go_library(
     tags = ["automanaged"],
     deps = [
         "//pkg/api/v1:go_default_library",
+        "//pkg/client/clientset_generated/clientset:go_default_library",
         "//pkg/client/clientset_generated/clientset/typed/core/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//vendor/k8s.io/client-go/tools/record:go_default_library",

pkg/client/leaderelection/resourcelock/interface.go

@@ -17,12 +17,17 @@ limitations under the License.
 package resourcelock
 
 import (
+	"fmt"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/tools/record"
+	cs "k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
 )
 
 const (
 	LeaderElectionRecordAnnotationKey = "control-plane.alpha.kubernetes.io/leader"
+	EndpointsResourceLock             = "endpoints"
+	ConfigMapsResourceLock            = "configmaps"
 )
 
 // LeaderElectionRecord is the record that is stored in the leader election annotation.
@@ -69,3 +74,29 @@ type Interface interface {
 	// into a string
 	Describe() string
 }
+
+// Manufacture will create a lock of a given type according to the input parameters
+func New(lockType string, ns string, name string, client *cs.Clientset, rlc ResourceLockConfig) (Interface, error) {
+	switch lockType {
+	case EndpointsResourceLock:
+		return &EndpointsLock{
+			EndpointsMeta: metav1.ObjectMeta{
+				Namespace: ns,
+				Name:      name,
+			},
+			Client:     client,
+			LockConfig: rlc,
+		}, nil
+	case ConfigMapsResourceLock:
+		return &ConfigMapLock{
+			ConfigMapMeta: metav1.ObjectMeta{
+				Namespace: ns,
+				Name:      name,
+			},
+			Client:     client,
+			LockConfig: rlc,
+		}, nil
+	default:
+		return nil, fmt.Errorf("Invalid lock-type %s", lockType)
+	}
+}

plugin/cmd/kube-scheduler/app/server.go

@@ -26,7 +26,6 @@ import (
 	goruntime "runtime"
 	"strconv"
 
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apiserver/pkg/server/healthz"
 
 	informers "k8s.io/kubernetes/pkg/client/informers/informers_generated/externalversions"
@@ -112,17 +111,16 @@ func Run(s *options.SchedulerServer) error {
 		return fmt.Errorf("unable to get hostname: %v", err)
 	}
 
-	// TODO: enable other lock types
-	rl := &resourcelock.EndpointsLock{
-		EndpointsMeta: metav1.ObjectMeta{
-			Namespace: s.LockObjectNamespace,
-			Name:      s.LockObjectName,
-		},
-		Client: kubecli,
-		LockConfig: resourcelock.ResourceLockConfig{
+	rl, err := resourcelock.New(s.LeaderElection.ResourceLock,
+		s.LockObjectNamespace,
+		s.LockObjectName,
+		kubecli,
+		resourcelock.ResourceLockConfig{
 			Identity:      id,
 			EventRecorder: recorder,
-		},
+		})
+	if err != nil {
+		glog.Fatalf("error creating lock: %v", err)
 	}
 
 	leaderelection.RunOrDie(leaderelection.LeaderElectionConfig{