docs: def _tar(name, root, path=None, compress='bzip2'):
      '''
      Pack up image in a tar format
      '''
      if path is None:
          path = os.path.join(salt.syspaths.BASE_FILE_ROOTS_DIR, 'img')
      if not __salt__['file.directory_exists'](path):
          try:
              __salt__['file.mkdir'](path)
          except Exception as exc:
              return {'Error': salt.utils.stringutils.to_unicode(pprint.pformat(exc))}
  
      compression, ext = _compress(compress)
  
      tarfile = '{0}/{1}.tar.{2}'.format(path, name, ext)
      out = __salt__['archive.tar'](
          options='{0}pcf'.format(compression),
          tarfile=tarfile,
          sources='.',
          dest=root,
      )