enable karmada-controller-manager health check endpoint /healthz (#154)

Signed-off-by: RainbowMango <renhongcai@huawei.com>

artifacts/deploy/controller-manager.yaml

@@ -26,6 +26,8 @@ spec:
           command:
             - /bin/karmada-controller-manager
             - --kubeconfig=/etc/kubeconfig
+            - --bind-address=0.0.0.0
+            - --secure-port=10357
           volumeMounts:
           - name: kubeconfig
             subPath: kubeconfig

cmd/controller-manager/app/controllermanager.go

@@ -11,6 +11,7 @@ import (
 	"k8s.io/component-base/logs"
 	"k8s.io/klog/v2"
 	"sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/healthz"
 
 	"github.com/karmada-io/karmada/cmd/controller-manager/app/options"
 	"github.com/karmada-io/karmada/pkg/controllers/binding"
@@ -42,6 +43,7 @@ func NewControllerManagerCommand(stopChan <-chan struct{}) *cobra.Command {
 	}
 
 	cmd.Flags().AddGoFlagSet(flag.CommandLine)
+	opts.AddFlags(cmd.Flags())
 	return cmd
 }
 
@@ -55,15 +57,22 @@ func Run(opts *options.Options, stopChan <-chan struct{}) error {
 		panic(err)
 	}
 	controllerManager, err := controllerruntime.NewManager(config, controllerruntime.Options{
-		Scheme:           gclient.NewSchema(),
-		LeaderElection:   true, // TODO(RainbowMango): Add a flag '--enable-leader-election' for this option.
-		LeaderElectionID: "41db11fa.karmada.io",
+		Scheme:                 gclient.NewSchema(),
+		LeaderElection:         true, // TODO(RainbowMango): Add a flag '--enable-leader-election' for this option.
+		LeaderElectionID:       "41db11fa.karmada.io",
+		HealthProbeBindAddress: fmt.Sprintf("%s:%d", opts.BindAddress, opts.SecurePort),
+		LivenessEndpointName:   "/healthz",
 	})
 	if err != nil {
 		klog.Errorf("failed to build controller manager: %v", err)
 		return err
 	}
 
+	if err = controllerManager.AddHealthzCheck("ping", healthz.Ping); err != nil {
+		klog.Errorf("failed to add health check endpoint: %v", err)
+		return err
+	}
+
 	setupControllers(controllerManager, stopChan)
 
 	// blocks until the stop channel is closed.

cmd/controller-manager/app/options/options.go

@@ -3,6 +3,7 @@ package options
 import (
 	"time"
 
+	"github.com/spf13/pflag"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/tools/leaderelection/resourcelock"
 	componentbaseconfig "k8s.io/component-base/config"
@@ -15,10 +16,20 @@ var (
 	defaultElectionRetryPeriod   = metav1.Duration{Duration: 2 * time.Second}
 )
 
+const (
+	defaultBindAddress = "0.0.0.0"
+	defaultPort        = 10357
+)
+
 // Options contains everything necessary to create and run controller-manager.
 type Options struct {
 	HostNamespace  string
 	LeaderElection componentbaseconfig.LeaderElectionConfiguration
+	// BindAddress is the IP address on which to listen for the --secure-port port.
+	BindAddress string
+	// SecurePort is the port that the the server serves at.
+	// Note: We hope support https in the future once controller-runtime provides the functionality.
+	SecurePort int
 }
 
 // NewOptions builds an empty options.
@@ -53,3 +64,11 @@ func (o *Options) Complete() {
 		klog.Infof("Set default value: Options.LeaderElection.RetryPeriod = %s", defaultElectionRetryPeriod.Duration.String())
 	}
 }
+
+// AddFlags adds flags to the specified FlagSet.
+func (o *Options) AddFlags(flags *pflag.FlagSet) {
+	flags.StringVar(&o.BindAddress, "bind-address", defaultBindAddress,
+		"The IP address on which to listen for the --secure-port port.")
+	flags.IntVar(&o.SecurePort, "secure-port", defaultPort,
+		"The secure port on which to serve HTTPS.")
+}