Add note about exiting on leader loss

Author: JoelSpeed

pkg/manager/internal.go

@@ -162,6 +162,9 @@ func (cm *controllerManager) Start(stop <-chan struct{}) error {
 		Callbacks: leaderelection.LeaderCallbacks{
 			OnStartedLeading: cm.start,
 			OnStoppedLeading: func() {
+				// Most implementations of leader election log.Fatal() here.
+				// Since Start is wrapped in log.Fatal when called, we can just return
+				// an error here which will cause the program to exit.
 				cm.errChan <- fmt.Errorf("leader election lost")
 			},
 		},