neutron-fwaas/neutron/agent/linux/external_process.py
Brian Haley 89e38929d2 Change daemon Pidfile class to not use root_helper
Some users of the Pidfile class don't specify root_helper,
which then defaults to 'sudo', which will generate an error.
Remove root_helper altogether since we actually don't need
root priveleges to read /proc/$pid/cmdline.

Changed code to use open.readline() instead of a shell, and
tweaked tests accordingly.

Also cleaned-up the rootwrap filters that allow it as they
are not used anymore.

Fixes bug 1218142

Change-Id: I6691feb1c9f7bfa261a7ec464fd8f3f92168c302
2013-09-10 13:04:14 -04:00

109 lines
3.4 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright 2012 New Dream Network, LLC (DreamHost)
#
# 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: Mark McClain, DreamHost
import os
from oslo.config import cfg
from neutron.agent.linux import ip_lib
from neutron.agent.linux import utils
from neutron.openstack.common import log as logging
LOG = logging.getLogger(__name__)
OPTS = [
cfg.StrOpt('external_pids',
default='$state_path/external/pids',
help=_('Location to store child pid files')),
]
cfg.CONF.register_opts(OPTS)
class ProcessManager(object):
"""An external process manager for Neutron spawned processes.
Note: The manager expects uuid to be in cmdline.
"""
def __init__(self, conf, uuid, root_helper='sudo', namespace=None):
self.conf = conf
self.uuid = uuid
self.root_helper = root_helper
self.namespace = namespace
def enable(self, cmd_callback):
if not self.active:
cmd = cmd_callback(self.get_pid_file_name(ensure_pids_dir=True))
if self.namespace:
ip_wrapper = ip_lib.IPWrapper(self.root_helper, self.namespace)
ip_wrapper.netns.execute(cmd)
else:
# For normal sudo prepend the env vars before command
utils.execute(cmd, self.root_helper)
def disable(self):
pid = self.pid
if self.active:
cmd = ['kill', '-9', pid]
utils.execute(cmd, self.root_helper)
elif pid:
LOG.debug(_('Process for %(uuid)s pid %(pid)d is stale, ignoring '
'command'), {'uuid': self.uuid, 'pid': pid})
else:
LOG.debug(_('No process started for %s'), self.uuid)
def get_pid_file_name(self, ensure_pids_dir=False):
"""Returns the file name for a given kind of config file."""
pids_dir = os.path.abspath(os.path.normpath(self.conf.external_pids))
if ensure_pids_dir and not os.path.isdir(pids_dir):
os.makedirs(pids_dir, 0o755)
return os.path.join(pids_dir, self.uuid + '.pid')
@property
def pid(self):
"""Last known pid for this external process spawned for this uuid."""
file_name = self.get_pid_file_name()
msg = _('Error while reading %s')
try:
with open(file_name, 'r') as f:
return int(f.read())
except IOError:
msg = _('Unable to access %s')
except ValueError:
msg = _('Unable to convert value in %s')
LOG.debug(msg, file_name)
return None
@property
def active(self):
pid = self.pid
if pid is None:
return False
cmdline = '/proc/%s/cmdline' % pid
try:
with open(cmdline, "r") as f:
return self.uuid in f.readline()
except IOError:
return False