✨ Disable the webhook server by setting the port to -1

pkg/manager/manager_test.go

@@ -160,6 +160,21 @@ var _ = Describe("manger.Manager", func() {
 			Expect(isCustomWebhook).To(BeTrue())
 		})
 
+		It("should create a webhook server that is disabled", func(specCtx SpecContext) {
+			By("setting the port to -1", func() {
+				srv := webhook.NewServer(webhook.Options{Port: -1})
+				m, err := New(cfg, Options{WebhookServer: srv})
+				Expect(err).NotTo(HaveOccurred())
+				Expect(m).NotTo(BeNil())
+
+				svr := m.GetWebhookServer()
+				Expect(svr).NotTo(BeNil())
+				Expect(svr.(*webhook.DefaultServer).Options.Port).To(Equal(-1))
+				Expect(svr.Start(specCtx)).NotTo(HaveOccurred())
+				Expect(svr.WebhookMux()).ToNot(BeNil())
+			})
+		})
+
 		Context("with leader election enabled", func() {
 			It("should only cancel the leader election after all runnables are done", func(specCtx SpecContext) {
 				m, err := New(cfg, Options{

pkg/webhook/server.go

@@ -75,6 +75,8 @@ type Options struct {
 
 	// Port is the port number that the server will serve.
 	// It will be defaulted to 9443 if unspecified.
+	//
+	// To disable the webhook server set Port to -1.
 	Port int
 
 	// CertDir is the directory that contains the server key and certificate. Defaults to
@@ -136,7 +138,7 @@ func (o *Options) setDefaults() {
 		o.WebhookMux = http.NewServeMux()
 	}
 
-	if o.Port <= 0 {
+	if o.Port == 0 {
 		o.Port = DefaultPort
 	}
 
@@ -180,14 +182,23 @@ func (s *DefaultServer) Register(path string, hook http.Handler) {
 	s.webhookMux.Handle(path, metrics.InstrumentedHook(path, hook))
 
 	regLog := log.WithValues("path", path)
-	regLog.Info("Registering webhook")
+	if s.Options.Port < 0 {
+		regLog.Info("Webhook is disabled")
+	} else {
+		regLog.Info("Registering webhook")
+	}
 }
 
 // Start runs the server.
 // It will install the webhook related resources depend on the server configuration.
 func (s *DefaultServer) Start(ctx context.Context) error {
 	s.defaultingOnce.Do(s.setDefaults)
 
+	if s.Options.Port < 0 {
+		log.Info("Webhook server is disabled")
+		return nil
+	}
+
 	log.Info("Starting webhook server")
 
 	cfg := &tls.Config{
@@ -278,6 +289,9 @@ func (s *DefaultServer) StartedChecker() healthz.Checker {
 		s.mu.Lock()
 		defer s.mu.Unlock()
 
+		if s.Options.Port < 0 {
+			return nil
+		}
 		if !s.started {
 			return fmt.Errorf("webhook server has not been started yet")
 		}