Make leader election lease duration configurable through manager options

Author: vikaschoudhary16

example_test.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"time"
 
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
@@ -59,6 +60,50 @@ func Example() {
 	}
 }
 
+// This example creates a simple application Controller that is configured for ReplicaSets and Pods.
+// This application controller will be running leader election with the provided configuration in the manager options.
+// If leader election configuration is not provided, controller runs leader election with default values.
+// Default values taken from: https://github.com/kubernetes/apiserver/blob/master/pkg/apis/config/v1alpha1/defaults.go
+//	defaultLeaseDuration = 15 * time.Second
+//	defaultRenewDeadline = 10 * time.Second
+//	defaultRetryPeriod   = 2 * time.Second
+//
+// * Create a new application for ReplicaSets that manages Pods owned by the ReplicaSet and calls into
+// ReplicaSetReconciler.
+//
+// * Start the application.
+// TODO(pwittrock): Update this example when we have better dependency injection support
+func Example_updateLeaderElectionDurations() {
+	var log = controllers.Log.WithName("builder-examples")
+	leaseDuration := 100 * time.Second
+	renewDeadline := 80 * time.Second
+	retryPeriod := 20 * time.Second
+	manager, err := controllers.NewManager(controllers.GetConfigOrDie(), controllers.Options{
+		LeaseDuration: &leaseDuration,
+		RenewDeadline: &renewDeadline,
+		RetryPeriod:   &retryPeriod,
+	})
+	if err != nil {
+		log.Error(err, "could not create manager")
+		os.Exit(1)
+	}
+
+	err = controllers.
+		NewControllerManagedBy(manager). // Create the Controller
+		For(&appsv1.ReplicaSet{}).       // ReplicaSet is the Application API
+		Owns(&corev1.Pod{}).             // ReplicaSet owns Pods created by it
+		Complete(&ReplicaSetReconciler{Client: manager.GetClient()})
+	if err != nil {
+		log.Error(err, "could not create controller")
+		os.Exit(1)
+	}
+
+	if err := manager.Start(controllers.SetupSignalHandler()); err != nil {
+		log.Error(err, "could not start manager")
+		os.Exit(1)
+	}
+}
+
 // ReplicaSetReconciler is a simple Controller example implementation.
 type ReplicaSetReconciler struct {
 	client.Client

pkg/manager/internal.go

@@ -40,6 +40,13 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 )
 
+const (
+	// Values taken from: https://github.com/kubernetes/apiserver/blob/master/pkg/apis/config/v1alpha1/defaults.go
+	defaultLeaseDuration = 15 * time.Second
+	defaultRenewDeadline = 10 * time.Second
+	defaultRetryPeriod   = 2 * time.Second
+)
+
 var log = logf.RuntimeLog.WithName("manager")
 
 type controllerManager struct {
@@ -101,6 +108,16 @@ type controllerManager struct {
 	host string
 
 	webhookServer *webhook.Server
+
+	// leaseDuration is the duration that non-leader candidates will
+	// wait to force acquire leadership.
+	leaseDuration time.Duration
+	// renewDeadline is the duration that the acting master will retry
+	// refreshing leadership before giving up.
+	renewDeadline time.Duration
+	// retryPeriod is the duration the LeaderElector clients should wait
+	// between tries of actions.
+	retryPeriod time.Duration
 }
 
 // Add sets dependencies on i, and adds it to the list of runnables to start.
@@ -287,12 +304,10 @@ func (cm *controllerManager) start() {
 
 func (cm *controllerManager) startLeaderElection() (err error) {
 	l, err := leaderelection.NewLeaderElector(leaderelection.LeaderElectionConfig{
-		Lock: cm.resourceLock,
-		// Values taken from: https://github.com/kubernetes/apiserver/blob/master/pkg/apis/config/v1alpha1/defaults.go
-		// TODO(joelspeed): These timings should be configurable
-		LeaseDuration: 15 * time.Second,
-		RenewDeadline: 10 * time.Second,
-		RetryPeriod:   2 * time.Second,
+		Lock:          cm.resourceLock,
+		LeaseDuration: cm.leaseDuration,
+		RenewDeadline: cm.renewDeadline,
+		RetryPeriod:   cm.retryPeriod,
 		Callbacks: leaderelection.LeaderCallbacks{
 			OnStartedLeading: func(_ context.Context) {
 				cm.start()

pkg/manager/manager.go

@@ -113,6 +113,17 @@ type Options struct {
 	// will use for holding the leader lock.
 	LeaderElectionID string
 
+	// LeaseDuration is the duration that non-leader candidates will
+	// wait to force acquire leadership. This is measured against time of
+	// last observed ack. Default is 15 seconds.
+	LeaseDuration *time.Duration
+	// RenewDeadline is the duration that the acting master will retry
+	// refreshing leadership before giving up. Default is 10 seconds.
+	RenewDeadline *time.Duration
+	// RetryPeriod is the duration the LeaderElector clients should wait
+	// between tries of actions. Default is 2 seconds.
+	RetryPeriod *time.Duration
+
 	// Namespace if specified restricts the manager's cache to watch objects in
 	// the desired namespace Defaults to all namespaces
 	//
@@ -173,6 +184,7 @@ func (r RunnableFunc) Start(s <-chan struct{}) error {
 }
 
 // New returns a new Manager for creating Controllers.
+// nolint: gocyclo
 func New(config *rest.Config, options Options) (Manager, error) {
 	// Initialize a rest.config if none was specified
 	if config == nil {
@@ -231,6 +243,17 @@ func New(config *rest.Config, options Options) (Manager, error) {
 
 	stop := make(chan struct{})
 
+	leaseDuration, renewDeadline, retryPeriod := defaultLeaseDuration, defaultRenewDeadline, defaultRetryPeriod
+	if options.LeaseDuration == nil {
+		leaseDuration = defaultLeaseDuration
+	}
+	if options.RenewDeadline == nil {
+		renewDeadline = defaultRenewDeadline
+	}
+	if options.RetryPeriod == nil {
+		retryPeriod = defaultRetryPeriod
+	}
+
 	return &controllerManager{
 		config:           config,
 		scheme:           options.Scheme,
@@ -247,6 +270,9 @@ func New(config *rest.Config, options Options) (Manager, error) {
 		internalStopper:  stop,
 		port:             options.Port,
 		host:             options.Host,
+		leaseDuration:    leaseDuration,
+		renewDeadline:    renewDeadline,
+		retryPeriod:      retryPeriod,
 	}, nil
 }