cdist-backup/cdist/exec/util.py
2016-07-15 08:22:05 +02:00

155 lines
5.4 KiB
Python

# -*- coding: utf-8 -*-
#
# 2016 Darko Poljak (darko.poljak at gmail.com)
#
# This file is part of cdist.
#
# cdist is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# cdist is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with cdist. If not, see <http://www.gnu.org/licenses/>.
#
#
import subprocess
import sys
from tempfile import TemporaryFile
import cdist
# IMPORTANT:
# with the code below in python 3.5 when command is executed and error
# occurs then stderr is not captured.
# As it seems from documentation, it is only captured when using
# subprocess.run method with stderr=subprocess.PIPE and is captured
# into CompletedProcess resulting object or into CalledProcessError
# in case of error (only if specified capturing).
#
# If using PIPE then the run is slow. run method uses communicate method
# and internally it uses buffering.
#
# For now we will use capturing only stdout. stderr is written directly to
# stderr from child process.
#
# STDERR_UNSUPPORTED = '<Not supported in this python version>'
#
#
# def call_get_output(command, env=None):
# """Run the given command with the given environment.
# Return the tuple of stdout and stderr output as a byte strings.
# """
#
# assert isinstance(command, (list, tuple)), (
# "list or tuple argument expected, got: {}".format(command))
#
# if sys.version_info >= (3, 5):
# return call_get_out_err(command, env)
# else:
# return (call_get_stdout(command, env), STDERR_UNSUPPORTED)
#
#
# def handle_called_process_error(err, command):
# if sys.version_info >= (3, 5):
# errout = err.stderr
# else:
# errout = STDERR_UNSUPPORTED
# raise cdist.Error("Command failed: " + " ".join(command) +
# " with returncode: {} and stdout: {}, stderr: {}".format(
# err.returncode, err.output, errout))
#
#
# def call_get_stdout(command, env=None):
# """Run the given command with the given environment.
# Return the stdout output as a byte string, stderr is ignored.
# """
# assert isinstance(command, (list, tuple)), (
# "list or tuple argument expected, got: {}".format(command))
#
# with TemporaryFile() as fout:
# subprocess.check_call(command, env=env, stdout=fout)
# fout.seek(0)
# output = fout.read()
#
# return output
#
#
# def call_get_out_err(command, env=None):
# """Run the given command with the given environment.
# Return the tuple of stdout and stderr output as a byte strings.
# """
# assert isinstance(command, (list, tuple)), (
# "list or tuple argument expected, got: {}".format(command))
#
# with TemporaryFile() as fout, TemporaryFile() as ferr:
# subprocess.check_call(command, env=env,
# stdout=fout, stderr=ferr)
# fout.seek(0)
# ferr.seek(0)
# output = (fout.read(), ferr.read())
#
# return output
#
# The code below with bufsize=0 does not work either, communicate
# internally uses buffering. It works in case of error, but if everything
# is ok and there is no output in stderr then execution is very very slow.
#
# def _call_get_out_err(command, env=None):
# """Run the given command with the given environment.
# Return the tuple of stdout and stderr output as a byte strings.
# """
# assert isinstance(command, (list, tuple)), (
# "list or tuple argument expected, got: {}".format(command))
#
# result = subprocess.run(command, env=env, bufsize=0,
# stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True)
#
# return (result.stdout, result.stderr)
def call_get_output(command, env=None):
"""Run the given command with the given environment.
Return the tuple of stdout and stderr output as a byte strings.
"""
assert isinstance(command, (list, tuple)), (
"list or tuple argument expected, got: {}".format(command))
return (_call_get_stdout(command, env), None)
def handle_called_process_error(err, command):
# Currently, stderr is not captured.
# errout = None
# raise cdist.Error("Command failed: " + " ".join(command) +
# (" with returncode: {}\n"
# "stdout: {}\n"
# "stderr: {}").format(
# err.returncode, err.output, errout))
raise cdist.Error("Command failed: " + " ".join(command) +
(" with returncode: {}\n"
"stdout: {}").format(
err.returncode, err.output))
def _call_get_stdout(command, env=None):
"""Run the given command with the given environment.
Return the stdout output as a byte string, stderr is ignored.
"""
assert isinstance(command, (list, tuple)), (
"list or tuple argument expected, got: {}".format(command))
with TemporaryFile() as fout:
subprocess.check_call(command, env=env, stdout=fout)
fout.seek(0)
output = fout.read()
return output