LeaderElectionRunnable interface updated

Author: GrigoriyMikhalkin

pkg/controller/controller.go

@@ -36,12 +36,11 @@ type Options struct {
 	// Reconciler reconciles an object
 	Reconciler reconcile.Reconciler
 
-	// LeaderElection determines whether or not to use leader election when
-	// starting the controller.
+	// LeaderElection determines whether or not to use leader election when starting the controller.
+	// Defaults to true
 	LeaderElection bool
 
-	// LeaderElectionID determines the name of the configmap that leader election
-	// will use for holding the leader lock.
+	// LeaderElectionID determines the name of the configmap that leader election will use for holding the leader lock.
 	LeaderElectionID string
 }
 

pkg/internal/controller/controller.go

@@ -265,10 +265,10 @@ func (c *Controller) updateMetrics(reconcileTime time.Duration) {
 	ctrlmetrics.ReconcileTime.WithLabelValues(c.Name).Observe(reconcileTime.Seconds())
 }
 
-func (c *Controller) GetLeaderElection() bool {
+func (c *Controller) NeedLeaderElection() bool {
 	return c.LeaderElection
 }
 
-func (c *Controller) GetLeaderElectionID() string {
+func (c *Controller) GetID() string {
 	return c.LeaderElectionID
 }

pkg/manager/internal.go

@@ -336,33 +336,33 @@ func (cm *controllerManager) startLeaderElectionRunnables() {
 		// Write any Start errors to a channel so we can return them
 		ctrl := c
 		go func() {
-			if sr, ok := ctrl.(SingletonRunnable); ok && sr.GetLeaderElection() {
-				runnableLeaderElectionID := ctrl.(SingletonRunnable).GetLeaderElectionID()
+			if leRunnable, ok := ctrl.(LeaderElectionRunnable); ok {
+				leID := leRunnable.GetID()
 
 				// Check that leader election ID is defined
-				if runnableLeaderElectionID == "" {
+				if leID == "" {
 					cm.errChan <- errors.New("LeaderElectionID must be configured")
 					return
 				}
 
 				// Check that leader election ID is unique
-				if _, exists := cm.resourceLocksMap[runnableLeaderElectionID]; exists {
+				if _, exists := cm.resourceLocksMap[leID]; exists {
 					cm.errChan <- errors.New("LeaderElectionID must be unique")
 					return
 				}
 
 				// Create resource lock
 				resourceLock, err := cm.newResourceLock(cm.config, cm.recorderProvider, crleaderelection.Options{
 					LeaderElection:          true,
-					LeaderElectionID:        runnableLeaderElectionID,
+					LeaderElectionID:        leID,
 					LeaderElectionNamespace: cm.leaderElectionNamespace,
 				})
 				if err != nil {
 					cm.errChan <- err
 				}
 
-				cm.resourceLocksMap[runnableLeaderElectionID] = resourceLock
-				err = cm.startLeaderElection(runnableLeaderElectionID, leaderelection.LeaderCallbacks{
+				cm.resourceLocksMap[leID] = resourceLock
+				err = cm.startLeaderElection(leID, leaderelection.LeaderCallbacks{
 					OnStartedLeading: func(_ context.Context) {
 						cm.errChan <- ctrl.Start(cm.internalStop)
 					},

pkg/manager/manager.go

@@ -190,16 +190,9 @@ type LeaderElectionRunnable interface {
 	// NeedLeaderElection returns true if the Runnable needs to be run in the leader election mode.
 	// e.g. controllers need to be run in leader election mode, while webhook server doesn't.
 	NeedLeaderElection() bool
-}
-
-// SingletonRunnable knows if Runnable needs leader election.
-// Runnable also have to be leader election Runnable(started after manager's leader election)
-type SingletonRunnable interface {
-	// GetLeaderElection returns true if need to perform leader election
-	GetLeaderElection() bool
 
-	// GetLeaderElectionID returns leader election ID
-	GetLeaderElectionID() string
+	// GetID returns leader election ID
+	GetID() string
 }
 
 // New returns a new Manager for creating Controllers.

pkg/manager/manager_test.go

@@ -289,7 +289,7 @@ var _ = Describe("manger.Manager", func() {
 				m, err := New(cfg, options)
 				Expect(err).ToNot(HaveOccurred())
 
-				r := &singletonRunnable{
+				r := &leRunnable{
 					leaderElectionID: "",
 				}
 				Expect(m.Add(r)).To(Succeed())
@@ -303,7 +303,7 @@ var _ = Describe("manger.Manager", func() {
 					m, err := New(cfg, options)
 					Expect(err).ToNot(HaveOccurred())
 
-					r := &singletonRunnable{
+					r := &leRunnable{
 						leaderElectionID: options.LeaderElectionID,
 					}
 					Expect(m.Add(r)).To(Succeed())
@@ -740,18 +740,18 @@ func (i *injectable) Start(<-chan struct{}) error {
 	return nil
 }
 
-type singletonRunnable struct {
+type leRunnable struct {
 	leaderElectionID string
 }
 
-func (*singletonRunnable) Start(<-chan struct{}) error {
+func (*leRunnable) Start(<-chan struct{}) error {
 	return nil
 }
 
-func (*singletonRunnable) GetLeaderElection() bool {
+func (*leRunnable) NeedLeaderElection() bool {
 	return true
 }
 
-func (sr *singletonRunnable) GetLeaderElectionID() string {
-	return sr.leaderElectionID
+func (le *leRunnable) GetID() string {
+	return le.leaderElectionID
 }

pkg/webhook/server.go

@@ -95,6 +95,10 @@ func (*Server) NeedLeaderElection() bool {
 	return false
 }
 
+func (*Server) GetID() string {
+	return ""
+}
+
 // Register marks the given webhook as being served at the given path.
 // It panics if two hooks are registered on the same path.
 func (s *Server) Register(path string, hook http.Handler) {