Add liveness probe

internal/pkg/cmd/reloader.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net/http"
 	"os"
 	"strings"
 
@@ -20,6 +21,11 @@ import (
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
+var (
+	// Used for liveness probe
+	healthy bool = true
+)
+
 // NewReloaderCommand starts the reloader controller
 func NewReloaderCommand() *cobra.Command {
 	cmd := &cobra.Command{
@@ -164,11 +170,11 @@ func startReloader(cmd *cobra.Command, args []string) {
 		lock := leadership.GetNewLock(clientset, constants.LockName, podName, podNamespace)
 		ctx, cancel := context.WithCancel(context.Background())
 		defer cancel()
-		leadership.RunLeaderElection(lock, ctx, cancel, podName, controllers)
-		return
+		leadership.RunLeaderElection(lock, ctx, cancel, podName, controllers, healthy)
 	}
 
-	select {}
+	http.HandleFunc("/live", healthz)
+	logrus.Fatal(http.ListenAndServe(":8080", nil))
 }
 
 func getIgnoredNamespacesList(cmd *cobra.Command) (util.List, error) {
@@ -203,3 +209,12 @@ func getIgnoredResourcesList(cmd *cobra.Command) (util.List, error) {
 
 	return ignoredResourcesList, nil
 }
+
+func healthz(w http.ResponseWriter, req *http.Request) {
+	if healthy {
+		w.WriteHeader(http.StatusOK)
+		return
+	}
+
+	w.WriteHeader(http.StatusInternalServerError)
+}

internal/pkg/leadership/leadership.go

@@ -26,7 +26,7 @@ func GetNewLock(clientset *kubernetes.Clientset, lockName, podname, namespace st
 }
 
 // runLeaderElection runs leadership election. If an instance of the controller is the leader and stops leading it will shutdown.
-func RunLeaderElection(lock *resourcelock.LeaseLock, ctx context.Context, cancel context.CancelFunc, id string, controllers []*controller.Controller) {
+func RunLeaderElection(lock *resourcelock.LeaseLock, ctx context.Context, cancel context.CancelFunc, id string, controllers []*controller.Controller, health bool) {
 	// Construct channels for the controllers to use
 	var stopChannels []chan struct{}
 	for i := 0; i < len(controllers); i++ {
@@ -49,6 +49,7 @@ func RunLeaderElection(lock *resourcelock.LeaseLock, ctx context.Context, cancel
 				logrus.Info("no longer leader, shutting down")
 				stopControllers(stopChannels)
 				cancel()
+				health = false
 			},
 			OnNewLeader: func(current_id string) {
 				if current_id == id {