code: func attachSecret(plug *sioPlugin, namespace string, configData map[string]string) error {
  	// load secret
  	secretRefName := configData[confKey.secretName]
  	kubeClient := plug.host.GetKubeClient()
  	secretMap, err := volutil.GetSecretForPV(namespace, secretRefName, sioPluginName, kubeClient)
  	if err != nil {
  		klog.Error(log("failed to get secret: %v", err))
  		return secretNotFoundErr
  	}
  	// merge secret data
  	for key, val := range secretMap {
  		configData[key] = val
  	}
  
  	return nil
  }
docs: // attachSecret loads secret object and attaches to configData