def execute(*cmd, **kwargs):
    """
    Helper method to execute command with optional retry.

    :cmd                Passed to subprocess.Popen.
    :process_input      Send to opened process.
    :check_exit_code    Defaults to 0. Raise exception.ProcessExecutionError
                        unless program exits with this code.
    :delay_on_retry     True | False. Defaults to True. If set to True, wait a
                        short amount of time before retrying.
    :attempts           How many times to retry cmd.
    :run_as_root        True | False. Defaults to False. If set to True,
                        the command is prefixed by the command specified
                        in the root_helper FLAG.

    :raises exception.Error on receiving unknown arguments
    :raises exception.ProcessExecutionError
    """

    process_input = kwargs.pop('process_input', None)
    check_exit_code = kwargs.pop('check_exit_code', 0)
    delay_on_retry = kwargs.pop('delay_on_retry', True)
    attempts = kwargs.pop('attempts', 1)
    run_as_root = kwargs.pop('run_as_root', False)
    if len(kwargs):
        raise exception.Error(_('Got unknown keyword args '
                                'to utils.execute: %r') % kwargs)

    if run_as_root:
        cmd = shlex.split(FLAGS.root_helper) + list(cmd)
    cmd = map(str, cmd)

    while attempts > 0:
        attempts -= 1
        try:
            #LOG.debug(_('Running cmd (subprocess): %s'), ' '.join(cmd))
            _PIPE = subprocess.PIPE  # pylint: disable=E1101
            obj = subprocess.Popen(cmd,
                                   stdin=_PIPE,
                                   stdout=_PIPE,
                                   stderr=_PIPE,
                                   close_fds=True)
            result = None
            if process_input is not None:
                result = obj.communicate(process_input)
            else:
                result = obj.communicate()
            obj.stdin.close()  # pylint: disable=E1101
            _returncode = obj.returncode  # pylint: disable=E1101
            if _returncode:
                LOG.debug(_('Result was %s') % _returncode)
                if type(check_exit_code) == types.IntType \
                        and _returncode != check_exit_code:
                    (stdout, stderr) = result
                    raise exception.ProcessExecutionError(
                            exit_code=_returncode,
                            stdout=stdout,
                            stderr=stderr,
                            cmd=' '.join(cmd))
            return result
        except exception.ProcessExecutionError:
            if not attempts:
                raise
            else:
                LOG.debug(_('%r failed. Retrying.'), cmd)
                if delay_on_retry:
                    greenthread.sleep(random.randint(20, 200) / 100.0)
        finally:
            # NOTE(termie): this appears to be necessary to let the subprocess
            #               call clean something up in between calls, without
            #               it two execute calls in a row hangs the second one
            greenthread.sleep(0)
dataset/ETHPy150Open nii-cloud/dodai-compute/nova/utils.py/execute/original