deb-python-os-brick/os_brick/executor.py
Angus Lees dbf77fba10 Trivial rootwrap -> privsep replacement
This change replaces all uses of rootwrap with a trivial privsep-based
equivalent.  This replacement simply executes commands as the privsep
user *without any additional checks*.

There are 2 reasons why this is a reasonable thing to do:

1. We don't have a good workflow for merging rootwrap filter changes
   into parent projects (nova/cinder) for a loosely-coupled library like
   os-brick.

2. The previous situation was also insecure.  The os-brick.filters
   rootwrap config permitted commands like "dd" and "cp" with any
   arguments, as root.  This would have posed only a mild inconvenience
   to an attacker.  With privsep we can at least (in principle) limit
   the commands to the privsep uid/gid and Linux
   capabilities (CAP_SYS_ADMIN by default with this change).

This change addresses the urgency of (1).   Later refactors will take
greater advantage of privsep to address (2).

Change-Id: I0af542eba97d2f89b1c283bf1e1e985d9690f5de
Depends-On: I90dc41bc77993bd83b80c92286e015e14f290b45
 # nova: nova.conf: Set privsep_rootwrap.helper_command
Depends-On: I4e333e73ddfd45c045b9d32dac1506fc25858c4d
 # nova: Add os-brick rootwrap filter for privsep
Depends-On: I8a0b1728cc66c4861f69623b1b16b1f759b57b25
 # cinder: cinder.conf: Set privsep_rootwrap.helper_command
Depends-On: I3b2e337321875cf4abc0ab9b44fe17cf9327d88b
 # cinder: Add os-brick rootwrap filter for privsep
Depends-On: I4299c2fc059807610f83e12a2d470e020930c64c
 # privsep: Switch to msgpack for serialization
Depends-On: Ied1ef4fc945e18516b39d1f20d58425cb633dc74
 # requirements: require oslo.privsep>=1.5.0 for msgpack fix
2016-04-15 15:29:25 +00:00

44 lines
1.7 KiB
Python

# (c) Copyright 2013 Hewlett-Packard Development Company, L.P.
#
# 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.
"""Generic exec utility that allows us to set the
execute and root_helper attributes for putils.
Some projects need their own execute wrapper
and root_helper settings, so this provides that hook.
"""
from oslo_concurrency import processutils as putils
from os_brick.privileged import rootwrap as priv_rootwrap
class Executor(object):
def __init__(self, root_helper, execute=None,
*args, **kwargs):
# For backwards compatibility, `putils.execute` is interpreted
# as a sentinel to mean "I want the os-brick default" :-/
# This can be burnt as soon as we update all the callsites (in
# nova+cinder) to the new default - and then we shall never
# speak of it again.
if execute is None or execute is putils.execute:
execute = priv_rootwrap.execute
self.set_execute(execute)
self.set_root_helper(root_helper)
def set_execute(self, execute):
self._execute = execute
def set_root_helper(self, helper):
self._root_helper = helper