vitessio/vitess · error

could not initConfig in %v: %v

Error message

could not initConfig in %v: %v

What it means

RefreshConfig generated a candidate my.cnf in a temp file but mysqld.initConfig failed while filling the template. The message includes the temp file name and the underlying cause (template rendering or hook failure).

Source

Thrown at go/vt/mysqlctl/mysqld.go:1576

		log.Info(fmt.Sprintf("executing Mysqld.RefreshConfig() remotely via mysqlctld server: %v", socketFile))
		client, err := mysqlctlclient.New(ctx, "unix", socketFile)
		if err != nil {
			return fmt.Errorf("can't dial mysqlctld: %v", err)
		}
		defer client.Close()
		return client.RefreshConfig(ctx)
	}

	log.Info("Checking for updates to my.cnf")
	f, err := os.CreateTemp(path.Dir(cnf.Path), "my.cnf")
	if err != nil {
		return fmt.Errorf("could not create temp file: %v", err)
	}

	defer os.Remove(f.Name())
	err = mysqld.initConfig(cnf, f.Name())
	if err != nil {
		return fmt.Errorf("could not initConfig in %v: %v", f.Name(), err)
	}

	existing, err := os.ReadFile(cnf.Path)
	if err != nil {
		return fmt.Errorf("could not read existing file %v: %v", cnf.Path, err)
	}
	updated, err := os.ReadFile(f.Name())
	if err != nil {
		return fmt.Errorf("could not read updated file %v: %v", f.Name(), err)
	}

	if bytes.Equal(existing, updated) {
		log.Info("No changes to my.cnf. Continuing.")
		return nil
	}

	backupPath := cnf.Path + ".previous"
	err = os.Rename(cnf.Path, backupPath)

View on GitHub (pinned to 01a25a7d17)

Solutions

1. Look at the wrapped cause to see whether it is a hook failure or template error, and fix accordingly.
2. Verify my.cnf template files exist in vtenv (share/vitess/mycnf).
3. Check MysqldParams values (paths, ports, server ID) are valid.
4. Run the same initConfig path during tablet init to confirm it works there.

Example fix

// before: missing template
// vtenv/share/vitess/mycnf/templates.cnf deleted
// after
// restore template: git checkout -- config/mycnf/templates.cnf (or reinstall vitess files)

for _, tmpl := range []string{"templates.cnf"} {
    if _, err := os.Stat(filepath.Join(vtenv.VtRoot(), "share", "vitess", "mycnf", tmpl)); err != nil {
        return fmt.Errorf("my.cnf template missing: %w", err)
    }
}

if err := mysqld.RefreshConfig(ctx, cnf); err != nil {
    if strings.Contains(err.Error(), "could not initConfig") {
        log.Errorf("template/hook failure generating my.cnf: %v", err)
    }
    return err
}

When it happens

Trigger: Mysqld.RefreshConfig local path: mysqld.initConfig(cnf, f.Name()) returns error — e.g. the make_mycnf hook fails or cnf.makeMycnf/getMycnfTemplate rendering fails.

Common situations: Broken make_mycnf hook (see hook-failed error); missing my.cnf template files; invalid parameters (bad paths/ports) interpolated into the template.

Related errors

• make_mycnf hook failed(%v): %v
• failed to generate vtgate consul datacenter from template: %
• failed to parse vtgate FQDN template %s: %w
• failed to parse vtgate host address template %s: %w
• failed to generate vtctld consul datacenter from template: %

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/5c1c5aea40720951. Report an issue: GitHub.