neutron-lbaas/quantum/rootwrap/wrapper.py

86 lines
3.0 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 os
import string
# this import has the effect of defining global var "filters",
# referenced by build_filter(), below. It gets set up by
# quantum-rootwrap, when we load_filters().
from quantum.rootwrap import filters
def build_filter(class_name, *args):
"""Returns a filter object of class class_name"""
if not hasattr(filters, class_name):
# TODO(jrd): Log the error (whenever quantum-rootwrap has a log file)
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
filterlist.append(newfilter)
return filterlist
def match_filter(filter_list, userargs):
"""
Checks user command and arguments through command filters and
returns the first matching filter, or None is none matched.
"""
found_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):
continue
# Try other filters if executable is absent
if not os.access(f.exec_path, os.X_OK):
if not found_filter:
found_filter = f
continue
# Otherwise return matching filter for execution
return f
# No filter matched or first missing executable
return found_filter