0717df0452
Alternative to using a sudoers file to limit which commands can be run as root in Nova. This one makes use of command filters defined in Nova code itself, which can be customized to deeply inspect command arguments before allowing a command to be executed. This change puts the infrastructure in place, together with command filters that replicate the level of filtering provided by a sudoers file (no deep argument inspection yet). An example of an advanced filter (RegExpFilter) is also provided. This new root wrapper is not active by default (root_helper still defaults to "sudo"). Implements blueprint nova-rootwrap. Change-Id: I7ad723b55e9446758876f21b4fbb09374a910425
60 lines
1.8 KiB
Python
Executable File
60 lines
1.8 KiB
Python
Executable File
# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (c) 2011 Openstack, LLC.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import os
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import sys
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FILTERS_MODULES = ['nova.rootwrap.compute',
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'nova.rootwrap.network',
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'nova.rootwrap.volume',
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]
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def load_filters():
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"""Load filters from modules present in nova.rootwrap."""
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filters = []
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for modulename in FILTERS_MODULES:
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try:
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__import__(modulename)
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module = sys.modules[modulename]
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filters = filters + module.filters
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except ImportError:
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# It's OK to have missing filters, since filter modules are
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# shipped with specific nodes rather than with python-nova
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pass
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return filters
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def match_filter(filters, userargs):
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"""
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Checks user command and arguments through command filters and
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returns the first matching filter, or None is none matched.
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"""
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for f in filters:
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if f.match(userargs):
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# Skip if executable is absent
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if not os.access(f.exec_path, os.X_OK):
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continue
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# Otherwise return matching filter for execution
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return f
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# No filter matched
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return None
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