From 073cfdfac909e30bec8bbc0978b67d803c60c038 Mon Sep 17 00:00:00 2001
From: "Lubomir I. Ivanov" <lubomirivanov@vmware.com>
Date: Sat, 6 Jan 2024 10:53:58 +0200
Subject: [PATCH] kubeadm: skip unmount on missing /var/lib/kubelet

If the user deletes the /var/lib/kubelet manually, "reset" will throw
an error that the dir is missing. Instead of handling this error,
print it as a warning and skip unmount of directories inside it.

This allows "reset" to continue to be reentrant and can be called
even even if "init/join" are not called yet and some of the
k8s directories on a node do not exist.

Continue to error on individual unmount errors.

Remove the function absoluteKubeletRunDirectory() and
call filepath.EvalSymlinks() directly.
---
 .../app/cmd/phases/reset/cleanupnode.go       | 31 ++++++++-----------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/cmd/kubeadm/app/cmd/phases/reset/cleanupnode.go b/cmd/kubeadm/app/cmd/phases/reset/cleanupnode.go
index 4979186dea4..d33a85c5761 100644
--- a/cmd/kubeadm/app/cmd/phases/reset/cleanupnode.go
+++ b/cmd/kubeadm/app/cmd/phases/reset/cleanupnode.go
@@ -81,18 +81,21 @@ func runCleanupNode(c workflow.RunData) error {
 	}
 
 	if !r.DryRun() {
-		// 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)
-		// In case KubeletRunDirectory holds a symbolic link, evaluate it
-		kubeletRunDirectory, err := absoluteKubeletRunDirectory()
+		// In case KubeletRunDirectory holds a symbolic link, evaluate it.
+		// This would also throw an error if the directory does not exist.
+		kubeletRunDirectory, err := filepath.EvalSymlinks(kubeadmconstants.KubeletRunDirectory)
 		if err != nil {
-			return err
+			klog.Warningf("[reset] Skipping unmount of directories in %q: %v\n",
+				kubeadmconstants.KubeletRunDirectory, err)
+		} else {
+			// Unmount all mount paths under kubeletRunDirectory.
+			fmt.Printf("[reset] Unmounting mounted directories in %q\n", kubeadmconstants.KubeletRunDirectory)
+			if err := unmountKubeletDirectory(kubeletRunDirectory, r.ResetCfg().UnmountFlags); err != nil {
+				return err
+			}
+			// Clean the kubeletRunDirectory.
+			dirsToClean = append(dirsToClean, kubeletRunDirectory)
 		}
-		// Unmount all mount paths under kubeletRunDirectory
-		if err := unmountKubeletDirectory(kubeletRunDirectory, r.ResetCfg().UnmountFlags); err != nil {
-			return err
-		}
-		dirsToClean = append(dirsToClean, kubeletRunDirectory)
 	} else {
 		fmt.Printf("[reset] Would unmount mounted directories in %q\n", kubeadmconstants.KubeletRunDirectory)
 	}
@@ -132,14 +135,6 @@ func runCleanupNode(c workflow.RunData) error {
 	return nil
 }
 
-func absoluteKubeletRunDirectory() (string, error) {
-	absoluteKubeletRunDirectory, err := filepath.EvalSymlinks(kubeadmconstants.KubeletRunDirectory)
-	if err != nil {
-		return "", errors.Wrapf(err, "failed to evaluate the %q directory", kubeadmconstants.KubeletRunDirectory)
-	}
-	return absoluteKubeletRunDirectory, nil
-}
-
 func removeContainers(execer utilsexec.Interface, criSocketPath string) error {
 	containerRuntime, err := utilruntime.NewContainerRuntime(execer, criSocketPath)
 	if err != nil {