kubernetes/kops · error

unable to read snippet: %s, error: %s

Error message

unable to read snippet: %s, error: %s

What it means

Returned by RunToolBoxTemplate when os.ReadFile fails on a snippet file that expandFiles successfully discovered. The glob expanded to a file list, but reading one of the individual files failed — typically a race (file deleted between listing and read), a permission error on the file itself, or a broken symlink.

Source

Thrown at cmd/kops/toolbox_template.go:162

	for _, x := range options.templatePath {
		list, err := expandFiles(utils.ExpandPath(x))
		if err != nil {
			return fmt.Errorf("unable to expand the template: %s, error: %s", x, err)
		}
		templates = append(templates, list...)
	}

	snippets := make(map[string]string)
	for _, x := range options.snippetsPath {
		list, err := expandFiles(utils.ExpandPath(x))
		if err != nil {
			return fmt.Errorf("unable to expand the snippets: %s, error: %s", x, err)
		}

		for _, j := range list {
			content, err := os.ReadFile(j)
			if err != nil {
				return fmt.Errorf("unable to read snippet: %s, error: %s", j, err)
			}
			snippets[path.Base(j)] = string(content)
		}
	}

	channel, err := kopsapi.LoadChannel(f.VFSContext(), options.channel)
	if err != nil {
		return fmt.Errorf("error loading channel %q: %v", options.channel, err)
	}

	// @step: render each of the templates, splitting on the documents
	r := templater.NewTemplater(channel)
	var documents []string
	for _, x := range templates {
		content, err := os.ReadFile(x)
		if err != nil {
			return fmt.Errorf("unable to read template: %s, error: %s", x, err)
		}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Check permissions on the specific file named in the error (ls -l) and grant read access (chmod/chown)
2. Verify the file exists and is a regular file, not a broken symlink: ls -lL <file>
3. Re-run after ensuring no concurrent process deletes files in the snippets directory
4. If files are on a network/EFS mount, verify the mount is healthy and remount if needed

Example fix

// before
-rw------- snippet.yaml  (owned by another user)

// after
chmod a+r ./snippets/snippet.yaml
kops toolbox template --template-path ./templates --snippets-path ./snippets --values values.yaml

matches, _ := filepath.Glob(snippetDir)
for _, f := range matches {
    if fi, err := os.Stat(f); err != nil || fi.IsDir() || fi.Mode().Perm()&0o400 == 0 {
        return fmt.Errorf("snippet %s unreadable", f)
    }
}

if _, err := os.ReadFile(snippetFile); err != nil {
    if errors.Is(err, os.ErrPermission) {
        return fmt.Errorf("fix permissions on %s: %w", snippetFile, err)
    }
    if errors.Is(err, os.ErrNotExist) {
        return fmt.Errorf("snippet %s disappeared or is a broken symlink", snippetFile)
    }
    return err
}

When it happens

Trigger: A snippet file listed by expandFiles is unreadable: permissions deny read for the kops user, the file was removed between glob expansion and ReadFile (CI cleanup, tmp dir), the entry is a dangling symlink, or it's a directory-ish entry without read access.

Common situations: Snippet files with restrictive modes (e.g. 0600 owned by another user) inside a shared snippets dir; snippets on a network mount that dropped out; CI pipelines cleaning up generated snippets mid-run; symlinked snippet dirs pointing to a removed location.

Related errors

• unable to expand the snippets: %s, error: %s
• unable to read template: %s, error: %s
• creating directory %q: %w
• creating file %q: %w
• error creating output directory %q: %v

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/9c89a53204d722c7. Report an issue: GitHub.