kubernetes/kops · error

error setting mode on temp file %q: %w

Error message

error setting mode on temp file %q: %w

What it means

Thrown by writeFileContents when setting the requested permission bits on the freshly written temp file fails. Chmod on a just-created temp file rarely fails; when it does it is usually an unsupported operation on the filesystem (e.g. NFS/overlay quirks) or the file descriptor was already invalidated.

Source

Thrown at upup/pkg/fi/files.go:92

	defer func() {
		if closeTempFile {
			if err := tempFile.Close(); err != nil {
				klog.Warningf("error closing tempfile %q: %v", tempFile.Name(), err)
			}
		}
		if deleteTempFile {
			if err := os.Remove(tempFile.Name()); err != nil {
				klog.Warningf("error removing tempfile %q: %v", tempFile.Name(), err)
			}
		}
	}()

	if _, err := io.Copy(tempFile, in); err != nil {
		return fmt.Errorf("error writing file %q: %v", tempFile.Name(), err)
	}

	if err := tempFile.Chmod(fileMode); err != nil {
		return fmt.Errorf("error setting mode on temp file %q: %w", tempFile.Name(), err)
	}

	if err := tempFile.Close(); err != nil {
		return fmt.Errorf("error closing temp file %q: %w", tempFile.Name(), err)
	}
	closeTempFile = false

	if err := os.Rename(tempFile.Name(), destPath); err != nil {
		return fmt.Errorf("error renaming temp file %q -> %q: %w", tempFile.Name(), destPath, err)
	}
	deleteTempFile = false

	return nil
}

func EnsureFileMode(destPath string, fileMode os.FileMode) (bool, error) {
	changed := false
	stat, err := os.Lstat(destPath)

View on GitHub (pinned to 4c8573c808)

Solutions

1. Check whether the destination filesystem supports chmod (avoid exotic mounts for node files)
2. Retry the operation — transient NFS/EIO failures on chmod are often sporadic
3. If persistently unsupported, write to a local filesystem and sync, or relax the file mode requirement

When it happens

Trigger: Thrown at upup/pkg/fi/files.go:92 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/be17841134def541. Report an issue: GitHub.