code: def list_snapshots(config_path=_DEFAULT_CONFIG_PATH, sort_by_time=False):
      '''
      Get a list of all the existing snapshots.
      :param str config_path: The path to the configuration file for the aptly instance.
      :param bool sort_by_time: Whether to sort by creation time instead of by name.
      :return: A list of the snapshot names.
      :rtype: list
      CLI Example:
      .. code-block:: bash
          salt '*' aptly.list_snapshots
      '''
      _validate_config(config_path)
      cmd = ['snapshot', 'list', '-config={}'.format(config_path), '-raw=true']
      if sort_by_time:
          cmd.append('-sort=time')
      else:
          cmd.append('-sort=name')
      cmd_ret = _cmd_run(cmd)
      ret = [line.strip() for line in cmd_ret.splitlines()]
      log.debug('Found snapshots: %s', len(ret))
      return ret