vmware-nsx/quantum/rootwrap/wrapper.py
Sergey Skripnick ecc0e7a9de Docstrings formatted according to pep257
Bug #1020184

quantum/*

Change-Id: I771e0f0d6121b7c03cecd82583e9a6c1915f891d
2013-05-17 16:26:08 +03:00

159 lines
5.9 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (c) 2012 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 string
from quantum.rootwrap import filters
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:
# Use system PATH if exec_dirs is not specified
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")
self.syslog_log_level = logging.getLevelName(v.upper())
if (self.syslog_log_level == "Level %s" % v.upper()):
raise ValueError('Unexepected syslog_log_level: %s' % 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
def setup_syslog(execname, facility, level):
rootwrap_logger = logging.getLogger()
rootwrap_logger.setLevel(level)
handler = logging.handlers.SysLogHandler(address='/dev/log',
facility=facility)
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 os.listdir(filterdir):
filterconfig = ConfigParser.RawConfigParser()
filterconfig.read(os.path.join(filterdir, filterfile))
for (name, value) in filterconfig.items("Filters"):
filterdefinition = [string.strip(s) for s in value.split(',')]
newfilter = build_filter(*filterdefinition)
if newfilter is None:
continue
newfilter.name = name
filterlist.append(newfilter)
return filterlist
def match_filter(filter_list, userargs, exec_dirs=[]):
"""Return first matched filter from command filters.
Checks user command and arguments through command filters and
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
for f in filter_list:
if f.match(userargs):
if isinstance(f, filters.ExecCommandFilter):
# This command calls exec verify that remaining args
# matches another filter.
leaf_filters = [fltr for fltr in filter_list
if not isinstance(fltr,
filters.ExecCommandFilter)]
args = f.exec_args(userargs)
if (not args or not
match_filter(leaf_filters, args, exec_dirs=exec_dirs)):
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()