tripleo-heat-templates/container_config_scripts/nova_statedir_ownership.py
Takashi Kajinami f47dfe1059 Enforce pep8/pyflakes rule on python codes
This change makes sure that we apply pyflake8 checks on all python
codes to improve its readability.

Note that there are some rules applied for other OpenStack projects,
but not yet turned on, which should be enabled in the future.

Change-Id: Iaf0299983d3a3fe48e3beb8f47bd33c21deb4972
2019-09-05 15:40:46 +09:00

178 lines
6.2 KiB
Python

#!/usr/bin/env python
#
# Copyright 2018 Red Hat Inc.
#
# 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.
from __future__ import print_function
import logging
import os
import pwd
import stat
import sys
debug = os.getenv('__OS_DEBUG', 'false')
if debug.lower() == 'true':
loglevel = logging.DEBUG
else:
loglevel = logging.INFO
logging.basicConfig(stream=sys.stdout, level=loglevel)
LOG = logging.getLogger('nova_statedir')
class PathManager(object):
"""Helper class to manipulate ownership of a given path"""
def __init__(self, path):
self.path = path
self._update()
def _update(self):
statinfo = os.stat(self.path)
self.is_dir = stat.S_ISDIR(statinfo.st_mode)
self.uid = statinfo.st_uid
self.gid = statinfo.st_gid
def __str__(self):
return "uid: {} gid: {} path: {}{}".format(
self.uid,
self.gid,
self.path,
'/' if self.is_dir else ''
)
def has_owner(self, uid, gid):
return self.uid == uid and self.gid == gid
def has_either(self, uid, gid):
return self.uid == uid or self.gid == gid
def chown(self, uid, gid):
target_uid = -1
target_gid = -1
if self.uid != uid:
target_uid = uid
if self.gid != gid:
target_gid = gid
if (target_uid, target_gid) != (-1, -1):
LOG.info('Changing ownership of %s from %d:%d to %d:%d',
self.path,
self.uid,
self.gid,
self.uid if target_uid == -1 else target_uid,
self.gid if target_gid == -1 else target_gid)
try:
os.chown(self.path, target_uid, target_gid)
self._update()
except Exception:
LOG.exception('Could not change ownership of %s: ',
self.path)
else:
LOG.info('Ownership of %s already %d:%d',
self.path,
uid,
gid)
class NovaStatedirOwnershipManager(object):
"""Class to manipulate the ownership of the nova statedir (/var/lib/nova).
The nova uid/gid differ on the host and container images. An upgrade
that switches from host systemd services to docker requires a change in
ownership. Previously this was a naive recursive chown, however this
causes issues if nova instance are shared via an NFS mount: any open
filehandles in qemu/libvirt fail with an I/O error (LP1778465).
Instead the upgrade/FFU ansible tasks now lay down a marker file when
stopping and disabling the host systemd services. We use this file to
determine the host nova uid/gid. We then walk the tree and update any
files that have the host uid/gid to the docker nova uid/gid. As files
owned by root/qemu etc... are ignored this avoids the issues with open
filehandles. The marker is removed once the tree has been walked.
For subsequent runs, or for a new deployment, we simply ensure that the
docker nova user/group owns all directories. This is required as the
directories are created with root ownership in host_prep_tasks (the
docker nova uid/gid is not known in this context).
"""
def __init__(self, statedir, upgrade_marker='upgrade_marker',
nova_user='nova'):
self.statedir = statedir
self.nova_user = nova_user
self.upgrade_marker_path = os.path.join(statedir, upgrade_marker)
self.upgrade = os.path.exists(self.upgrade_marker_path)
self.target_uid, self.target_gid = self._get_nova_ids()
self.previous_uid, self.previous_gid = self._get_previous_nova_ids()
self.id_change = (self.target_uid, self.target_gid) != \
(self.previous_uid, self.previous_gid)
def _get_nova_ids(self):
nova_uid, nova_gid = pwd.getpwnam(self.nova_user)[2:4]
return nova_uid, nova_gid
def _get_previous_nova_ids(self):
if self.upgrade:
statinfo = os.stat(self.upgrade_marker_path)
return statinfo.st_uid, statinfo.st_gid
else:
return self._get_nova_ids()
def _walk(self, top):
for f in os.listdir(top):
pathname = os.path.join(top, f)
if pathname == self.upgrade_marker_path:
continue
pathinfo = PathManager(pathname)
LOG.info("Checking %s", pathinfo)
if pathinfo.is_dir:
# Always chown the directories
pathinfo.chown(self.target_uid, self.target_gid)
self._walk(pathname)
elif self.id_change:
# Only chown files if it's an upgrade and the file is owned by
# the host nova uid/gid
pathinfo.chown(
self.target_uid if pathinfo.uid == self.previous_uid
else pathinfo.uid,
self.target_gid if pathinfo.gid == self.previous_gid
else pathinfo.gid
)
def run(self):
LOG.info('Applying nova statedir ownership')
LOG.info('Target ownership for %s: %d:%d',
self.statedir,
self.target_uid,
self.target_gid)
pathinfo = PathManager(self.statedir)
LOG.info("Checking %s", pathinfo)
pathinfo.chown(self.target_uid, self.target_gid)
self._walk(self.statedir)
if self.upgrade:
LOG.info('Removing upgrade_marker %s',
self.upgrade_marker_path)
os.unlink(self.upgrade_marker_path)
LOG.info('Nova statedir ownership complete')
if __name__ == '__main__':
NovaStatedirOwnershipManager('/var/lib/nova').run()