Merge pull request #17756 from zhengguoyong/check_ref_before_use

pkg/kubelet/kubelet.go

@@ -1646,18 +1646,15 @@ func (kl *Kubelet) syncPod(pod *api.Pod, mirrorPod *api.Pod, runningPod kubecont
 		return err
 	}
 
-	// Starting phase:
-	ref, err := api.GetReference(pod)
-	if err != nil {
-		glog.Errorf("Couldn't make a ref to pod %q: '%v'", podFullName, err)
-	}
-
 	// Mount volumes.
 	podVolumes, err := kl.mountExternalVolumes(pod)
 	if err != nil {
-		kl.recorder.Eventf(ref, api.EventTypeWarning, kubecontainer.FailedMountVolume, "Unable to mount volumes for pod %q: %v", podFullName, err)
-		glog.Errorf("Unable to mount volumes for pod %q: %v; skipping pod", podFullName, err)
-		return err
+		ref, errGetRef := api.GetReference(pod)
+		if errGetRef == nil && ref != nil {
+			kl.recorder.Eventf(ref, api.EventTypeWarning, kubecontainer.FailedMountVolume, "Unable to mount volumes for pod %q: %v", podFullName, err)
+			glog.Errorf("Unable to mount volumes for pod %q: %v; skipping pod", podFullName, err)
+			return err
+		}
 	}
 	kl.volumeManager.SetVolumes(pod.UID, podVolumes)