getUserPayload = (data = {}) => {
  const payload = yaml.safeLoad(fs.readFileSync(userTemplate));
  const username = data.username || 'admin';
  const password = data.password || 'default_password';
  const grouplist = data.grouplist || [];
  payload.metadata.name = Buffer.from(username).toString('hex');
  payload.data.username = Buffer.from(username).toString('base64');
  payload.data.password = Buffer.from(encrypt(username, password)).toString('base64');
  payload.data.grouplist = Buffer.from(JSON.stringify(grouplist)).toString('base64');
  return payload;
}
@param {Object} data - user info.
@param {string} data.username
@param {string} data.password
@param {string[]} data.grouplist