astara/akanda/rug/common/linux/utils.py

123 lines
4.1 KiB
Python

# Copyright 2014 DreamHost, LLC
#
# Author: DreamHost, LLC
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 Locaweb.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
# @author: Juliano Martinez, Locaweb.
import fcntl
import os
import shlex
import signal
import socket
import struct
import tempfile
from eventlet.green import subprocess
from akanda.rug.openstack.common.gettextutils import _
from akanda.rug.openstack.common import log as logging
LOG = logging.getLogger(__name__)
def _subprocess_setup():
# Python installs a SIGPIPE handler by default. This is usually not what
# non-Python subprocesses expect.
signal.signal(signal.SIGPIPE, signal.SIG_DFL)
def subprocess_popen(args, stdin=None, stdout=None, stderr=None, shell=False,
env=None):
return subprocess.Popen(args, shell=shell, stdin=stdin, stdout=stdout,
stderr=stderr, preexec_fn=_subprocess_setup,
close_fds=True, env=env)
def execute(cmd, root_helper=None, process_input=None, addl_env=None,
check_exit_code=True, return_stderr=False):
if root_helper:
cmd = shlex.split(root_helper) + cmd
cmd = map(str, cmd)
LOG.debug(_("Running command: %s"), cmd)
env = os.environ.copy()
if addl_env:
env.update(addl_env)
obj = subprocess_popen(cmd, shell=False,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
env=env)
_stdout, _stderr = (process_input and
obj.communicate(process_input) or
obj.communicate())
obj.stdin.close()
m = _("\nCommand: %(cmd)s\nExit code: %(code)s\nStdout: %(stdout)r\n"
"Stderr: %(stderr)r") % {'cmd': cmd, 'code': obj.returncode,
'stdout': _stdout, 'stderr': _stderr}
LOG.debug(m)
if obj.returncode and check_exit_code:
raise RuntimeError(m)
return return_stderr and (_stdout, _stderr) or _stdout
def get_interface_mac(interface):
DEVICE_NAME_LEN = 15
MAC_START = 18
MAC_END = 24
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
info = fcntl.ioctl(s.fileno(), 0x8927,
struct.pack('256s', interface[:DEVICE_NAME_LEN]))
return ''.join(['%02x:' % ord(char)
for char in info[MAC_START:MAC_END]])[:-1]
def replace_file(file_name, data):
"""Replaces the contents of file_name with data in a safe manner.
First write to a temp file and then rename. Since POSIX renames are
atomic, the file is unlikely to be corrupted by competing writes.
We create the tempfile on the same device to ensure that it can be renamed.
"""
base_dir = os.path.dirname(os.path.abspath(file_name))
tmp_file = tempfile.NamedTemporaryFile('w+', dir=base_dir, delete=False)
tmp_file.write(data)
tmp_file.close()
os.chmod(tmp_file.name, 0644)
os.rename(tmp_file.name, file_name)