nova/bin/nova-rootwrap

129 lines
4.5 KiB
Python
Executable File

#!/usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (c) 2011 OpenStack Foundation
# 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.
"""Root wrapper for OpenStack services
Filters which commands a service is allowed to run as another user.
To use this with nova, you should set the following in
nova.conf:
rootwrap_config=/etc/nova/rootwrap.conf
You also need to let the nova user run nova-rootwrap
as root in sudoers:
nova ALL = (root) NOPASSWD: /usr/bin/nova-rootwrap
/etc/nova/rootwrap.conf *
Service packaging should deploy .filters files only on nodes where
they are needed, to avoid allowing more than is necessary.
"""
import ConfigParser
import logging
import os
import pwd
import signal
import subprocess
import sys
RC_UNAUTHORIZED = 99
RC_NOCOMMAND = 98
RC_BADCONFIG = 97
RC_NOEXECFOUND = 96
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 _exit_error(execname, message, errorcode, log=True):
print "%s: %s" % (execname, message)
if log:
logging.error(message)
sys.exit(errorcode)
if __name__ == '__main__':
# Split arguments, require at least a command
execname = sys.argv.pop(0)
if len(sys.argv) < 2:
_exit_error(execname, "No command specified", RC_NOCOMMAND, log=False)
configfile = sys.argv.pop(0)
userargs = sys.argv[:]
# Add ../ to sys.path to allow running from branch
possible_topdir = os.path.normpath(os.path.join(os.path.abspath(execname),
os.pardir, os.pardir))
if os.path.exists(os.path.join(possible_topdir, "nova", "__init__.py")):
sys.path.insert(0, possible_topdir)
from nova.openstack.common.rootwrap import wrapper
# Load configuration
try:
rawconfig = ConfigParser.RawConfigParser()
rawconfig.read(configfile)
config = wrapper.RootwrapConfig(rawconfig)
except ValueError as exc:
msg = "Incorrect value in %s: %s" % (configfile, exc.message)
_exit_error(execname, msg, RC_BADCONFIG, log=False)
except ConfigParser.Error:
_exit_error(execname, "Incorrect configuration file: %s" % configfile,
RC_BADCONFIG, log=False)
if config.use_syslog:
wrapper.setup_syslog(execname,
config.syslog_log_facility,
config.syslog_log_level)
# Execute command if it matches any of the loaded filters
filters = wrapper.load_filters(config.filters_path)
try:
filtermatch = wrapper.match_filter(filters, userargs,
exec_dirs=config.exec_dirs)
if filtermatch:
command = filtermatch.get_command(userargs,
exec_dirs=config.exec_dirs)
if config.use_syslog:
logging.info("(%s > %s) Executing %s (filter match = %s)" % (
os.getlogin(), pwd.getpwuid(os.getuid())[0],
command, filtermatch.name))
obj = subprocess.Popen(command,
stdin=sys.stdin,
stdout=sys.stdout,
stderr=sys.stderr,
preexec_fn=_subprocess_setup,
env=filtermatch.get_environment(userargs))
obj.wait()
sys.exit(obj.returncode)
except wrapper.FilterMatchNotExecutable as exc:
msg = ("Executable not found: %s (filter match = %s)"
% (exc.match.exec_path, exc.match.name))
_exit_error(execname, msg, RC_NOEXECFOUND, log=config.use_syslog)
except wrapper.NoFilterMatched:
msg = ("Unauthorized command: %s (no filter matched)"
% ' '.join(userargs))
_exit_error(execname, msg, RC_UNAUTHORIZED, log=config.use_syslog)