code: def check_remote_host_marker_file(host, file_path):
      
      log = logging.getLogger(mod_logger + '.check_remote_host_marker_file')
      if not isinstance(host, basestring):
          msg = 'host argument must be a string'
          log.error(msg)
          raise TypeError(msg)
      if not isinstance(file_path, basestring):
          msg = 'file_path argument must be a string'
          log.error(msg)
          raise TypeError(msg)
      log.debug('Checking host {h} for marker file: {f}...'.format(h=host, f=file_path))
      command = ['ssh', '{h}'.format(h=host), 'if [ -f {f} ] ; then exit 0 ; else exit 1 ; fi'.format(f=file_path)]
      try:
          result = run_command(command, timeout_sec=5.0)
          code = result['code']
          output = result['output']
      except CommandError:
          raise
      if code == 0:
          log.debug('Marker file <{f}> was found on host {h}'.format(f=file_path, h=host))
          return True
      elif code == 1 and output == '':
          log.debug('Marker file <{f}> was not found on host {h}'.format(f=file_path, h=host))
          return False
      else:
          msg = 'There was a problem checking the remote host {h} over SSH for marker file {f}, ' \
                'command returned code {c} and produced output: {o}'.format(
                  h=host, f=file_path, c=code, o=output)
          log.debug(msg)
          raise CommandError(msg)
docs: Queries a remote host over SSH to check for existence
      of a marker file
  
      :param host: (str) host to query
      :param file_path: (str) path to the marker file
      :return: (bool) True if the marker file exists
      :raises: TypeError, CommandError