vmware-nsx/quantum/agent/linux/utils.py
Mark McClain 0ade06453c LBaaS Agent Reference Implementation
implements blueprint lbaas-namespace-agent

This a reference implemention of the Quantum load balancing service
using HAProxy.  The implemention is designed for vendors, developers,
and deployers to become familiar with the API and service workflow.

This change also adds some constraint checks for data integrity.

Change-Id: I10a67da11840477ccf063b98149f4f77248802a1
2013-02-27 21:49:57 -05:00

92 lines
3.0 KiB
Python

# 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 socket
import struct
import tempfile
from eventlet.green import subprocess
from quantum.common import utils
from quantum.openstack.common import log as logging
LOG = logging.getLogger(__name__)
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 = utils.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)