3c87de7c12
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
73 lines
2.5 KiB
Python
Executable File
73 lines
2.5 KiB
Python
Executable File
#!/usr/bin/env python
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# 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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"""Root wrapper for Nova
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Uses modules in nova.rootwrap containing filters for commands
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that nova is allowed to run as another user.
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To switch to using this, you should:
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* Set "--root_helper=sudo nova-rootwrap" in nova.conf
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* Allow nova to run nova-rootwrap as root in nova_sudoers:
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nova ALL = (root) NOPASSWD: /usr/bin/nova-rootwrap
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(all other commands can be removed from this file)
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To make allowed commands node-specific, your packaging should only
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install nova/rootwrap/{compute,network,volume}.py respectively on
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compute, network and volume nodes (i.e. nova-api nodes should not
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have any of those files installed).
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"""
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import os
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import subprocess
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import sys
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RC_UNAUTHORIZED = 99
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RC_NOCOMMAND = 98
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if __name__ == '__main__':
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# Split arguments, require at least a command
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execname = sys.argv.pop(0)
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if len(sys.argv) == 0:
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print "%s: %s" % (execname, "No command specified")
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sys.exit(RC_NOCOMMAND)
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userargs = sys.argv[:]
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# Add ../ to sys.path to allow running from branch
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possible_topdir = os.path.normpath(os.path.join(os.path.abspath(execname),
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os.pardir, os.pardir))
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if os.path.exists(os.path.join(possible_topdir, "nova", "__init__.py")):
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sys.path.insert(0, possible_topdir)
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from nova.rootwrap import wrapper
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# Execute command if it matches any of the loaded filters
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filters = wrapper.load_filters()
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filtermatch = wrapper.match_filter(filters, userargs)
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if filtermatch:
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obj = subprocess.Popen(filtermatch.get_command(userargs),
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stdin=sys.stdin,
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stdout=sys.stdout,
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stderr=sys.stderr)
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sys.exit(obj.returncode)
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print "Unauthorized command: %s" % ' '.join(userargs)
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sys.exit(RC_UNAUTHORIZED)
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