Merge pull request #77507 from cuericlee/patch-1

cmd/kubeadm/app/cmd/reset.go

@@ -279,12 +279,23 @@ func (r *resetData) Run() error {
 
 	// Try to unmount mounted directories under kubeadmconstants.KubeletRunDirectory in order to be able to remove the kubeadmconstants.KubeletRunDirectory directory later
 	fmt.Printf("[reset] Unmounting mounted directories in %q\n", kubeadmconstants.KubeletRunDirectory)
-	umountDirsCmd := fmt.Sprintf("awk '$2 ~ path {print $2}' path=%s/ /proc/mounts | xargs -r umount", kubeadmconstants.KubeletRunDirectory)
 
+	// In case KubeletRunDirectory holds a symbolic link, evaluate it
+	var absoluteKubeletRunDirectory string
+	absoluteKubeletRunDirectory, err = filepath.EvalSymlinks(kubeadmconstants.KubeletRunDirectory)
+	if err != nil {
+		klog.Errorf("[reset] Failed to evaluate the %q directory. Skipping its unmount and cleanup: %v", kubeadmconstants.KubeletRunDirectory, err)
+	} else {
+		// Only unmount mount points which start with "/var/lib/kubelet" or absolute path of symbolic link, and avoid using empty absoluteKubeletRunDirectory
+		umountDirsCmd := fmt.Sprintf("awk '$2 ~ path {print $2}' path=%s/ /proc/mounts | xargs -r umount", absoluteKubeletRunDirectory)
 		klog.V(1).Infof("[reset] Executing command %q", umountDirsCmd)
 		umountOutputBytes, err := exec.Command("sh", "-c", umountDirsCmd).Output()
 		if err != nil {
 			klog.Errorf("[reset] Failed to unmount mounted directories in %s: %s\n", kubeadmconstants.KubeletRunDirectory, string(umountOutputBytes))
+		} else {
+			// Only clean absoluteKubeletRunDirectory if umountDirsCmd passed without error
+			dirsToClean = append(dirsToClean, absoluteKubeletRunDirectory)
+		}
 	}
 
 	klog.V(1).Info("[reset] Removing Kubernetes-managed containers")
@@ -292,7 +303,7 @@ func (r *resetData) Run() error {
 		klog.Errorf("[reset] Failed to remove containers: %v", err)
 	}
 
-	dirsToClean = append(dirsToClean, []string{kubeadmconstants.KubeletRunDirectory, "/etc/cni/net.d", "/var/lib/dockershim", "/var/run/kubernetes"}...)
+	dirsToClean = append(dirsToClean, []string{"/etc/cni/net.d", "/var/lib/dockershim", "/var/run/kubernetes"}...)
 
 	// Then clean contents from the stateful kubelet, etcd and cni directories
 	fmt.Printf("[reset] Deleting contents of stateful directories: %v\n", dirsToClean)