oslo.rootwrap/oslo_rootwrap/wrapper.py
wangzihao 0e62293a43 Remove six
Replace the following items with Python 3 style code.

- six.moves
- six.StringIO

Change-Id: Ie06dc3b6cc5a3d88defa4fdfd071ed2c9dcfb1d0
2020-10-09 09:19:18 +08:00

236 lines
8.5 KiB
Python

# 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.
import configparser
import logging
import logging.handlers
import os
import signal
import sys
from oslo_rootwrap import filters
from oslo_rootwrap import subprocess
if sys.platform != 'win32':
import pwd
class NoFilterMatched(Exception):
"""This exception is raised when no filter matched."""
pass
class FilterMatchNotExecutable(Exception):
"""Raised when a filter matched but no executable was found."""
def __init__(self, match=None, **kwargs):
self.match = match
class RootwrapConfig(object):
def __init__(self, config):
# filters_path
self.filters_path = config.get("DEFAULT", "filters_path").split(",")
# exec_dirs
if config.has_option("DEFAULT", "exec_dirs"):
self.exec_dirs = config.get("DEFAULT", "exec_dirs").split(",")
else:
self.exec_dirs = []
# Use system PATH if exec_dirs is not specified
if "PATH" in os.environ:
self.exec_dirs = os.environ['PATH'].split(':')
# syslog_log_facility
if config.has_option("DEFAULT", "syslog_log_facility"):
v = config.get("DEFAULT", "syslog_log_facility")
facility_names = logging.handlers.SysLogHandler.facility_names
self.syslog_log_facility = getattr(logging.handlers.SysLogHandler,
v, None)
if self.syslog_log_facility is None and v in facility_names:
self.syslog_log_facility = facility_names.get(v)
if self.syslog_log_facility is None:
raise ValueError('Unexpected syslog_log_facility: %s' % v)
else:
default_facility = logging.handlers.SysLogHandler.LOG_SYSLOG
self.syslog_log_facility = default_facility
# syslog_log_level
if config.has_option("DEFAULT", "syslog_log_level"):
v = config.get("DEFAULT", "syslog_log_level")
level = v.upper()
if (hasattr(logging, '_nameToLevel') and
level in logging._nameToLevel):
# Workaround a regression of Python 3.4.0 bug fixed in 3.4.2:
# http://bugs.python.org/issue22386
self.syslog_log_level = logging._nameToLevel[level]
else:
self.syslog_log_level = logging.getLevelName(level)
if (self.syslog_log_level == "Level %s" % level):
raise ValueError('Unexpected syslog_log_level: %r' % v)
else:
self.syslog_log_level = logging.ERROR
# use_syslog
if config.has_option("DEFAULT", "use_syslog"):
self.use_syslog = config.getboolean("DEFAULT", "use_syslog")
else:
self.use_syslog = False
# daemon_timeout
if config.has_option("DEFAULT", "daemon_timeout"):
self.daemon_timeout = int(config.get("DEFAULT", "daemon_timeout"))
else:
self.daemon_timeout = 600
# fd ulimit
if config.has_option("DEFAULT", "rlimit_nofile"):
self.rlimit_nofile = int(config.get("DEFAULT", "rlimit_nofile"))
else:
self.rlimit_nofile = 1024
def setup_syslog(execname, facility, level):
try:
handler = logging.handlers.SysLogHandler(address='/dev/log',
facility=facility)
except IOError:
logging.warning("Unable to setup syslog, maybe /dev/log socket needs "
"to be restarted. Ignoring syslog configuration "
"options.")
return
rootwrap_logger = logging.getLogger()
rootwrap_logger.setLevel(level)
handler.setFormatter(logging.Formatter(
os.path.basename(execname) + ': %(message)s'))
rootwrap_logger.addHandler(handler)
def build_filter(class_name, *args):
"""Returns a filter object of class class_name."""
if not hasattr(filters, class_name):
logging.warning("Skipping unknown filter class (%s) specified "
"in filter definitions" % class_name)
return None
filterclass = getattr(filters, class_name)
return filterclass(*args)
def load_filters(filters_path):
"""Load filters from a list of directories."""
filterlist = []
for filterdir in filters_path:
if not os.path.isdir(filterdir):
continue
for filterfile in filter(lambda f: not f.startswith('.'),
os.listdir(filterdir)):
filterfilepath = os.path.join(filterdir, filterfile)
if not os.path.isfile(filterfilepath):
continue
kwargs = {"strict": False}
filterconfig = configparser.RawConfigParser(**kwargs)
filterconfig.read(filterfilepath)
for (name, value) in filterconfig.items("Filters"):
filterdefinition = [s.strip() for s in value.split(',')]
newfilter = build_filter(*filterdefinition)
if newfilter is None:
continue
newfilter.name = name
filterlist.append(newfilter)
# And always include privsep-helper
privsep = build_filter("CommandFilter", "privsep-helper", "root")
privsep.name = "privsep-helper"
filterlist.append(privsep)
return filterlist
def match_filter(filter_list, userargs, exec_dirs=None):
"""Checks user command and arguments through command filters.
Returns the first matching filter.
Raises NoFilterMatched if no filter matched.
Raises FilterMatchNotExecutable if no executable was found for the
best filter match.
"""
first_not_executable_filter = None
exec_dirs = exec_dirs or []
for f in filter_list:
if f.match(userargs):
if isinstance(f, filters.ChainingFilter):
# This command calls exec verify that remaining args
# matches another filter.
def non_chain_filter(fltr):
return (fltr.run_as == f.run_as and
not isinstance(fltr, filters.ChainingFilter))
leaf_filters = [fltr for fltr in filter_list
if non_chain_filter(fltr)]
args = f.exec_args(userargs)
if not args:
continue
try:
match_filter(leaf_filters, args, exec_dirs=exec_dirs)
except (NoFilterMatched, FilterMatchNotExecutable):
continue
# Try other filters if executable is absent
if not f.get_exec(exec_dirs=exec_dirs):
if not first_not_executable_filter:
first_not_executable_filter = f
continue
# Otherwise return matching filter for execution
return f
if first_not_executable_filter:
# A filter matched, but no executable was found for it
raise FilterMatchNotExecutable(match=first_not_executable_filter)
# No filter matched
raise NoFilterMatched()
def _getlogin():
try:
return os.getlogin()
except OSError:
return (os.getenv('USER') or
os.getenv('USERNAME') or
os.getenv('LOGNAME'))
def start_subprocess(filter_list, userargs, exec_dirs=[], log=False, **kwargs):
filtermatch = match_filter(filter_list, userargs, exec_dirs)
command = filtermatch.get_command(userargs, exec_dirs)
if log:
logging.info("(%s > %s) Executing %s (filter match = %s)" % (
_getlogin(), pwd.getpwuid(os.getuid())[0],
command, filtermatch.name))
def preexec():
# Python installs a SIGPIPE handler by default. This is
# usually not what non-Python subprocesses expect.
signal.signal(signal.SIGPIPE, signal.SIG_DFL)
filtermatch.preexec()
obj = subprocess.Popen(command,
preexec_fn=preexec,
env=filtermatch.get_environment(userargs),
**kwargs)
return obj