59 lines
1.7 KiB
Python
59 lines
1.7 KiB
Python
# Copyright (c) 2017 Thales Services SAS
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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 contextlib
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import os
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from oslo_log import log as logging
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from pyroute2 import netns as pynetns
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from neutron_fwaas._i18n import _
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PROCESS_NETNS = '/proc/self/ns/net'
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LOG = logging.getLogger(__name__)
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class BackInNamespaceExit(SystemExit):
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"""Raised if we fail to moved back process in its original namespace."""
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@contextlib.contextmanager
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def in_namespace(namespace):
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"""Move current process in a specific namespace.
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This contextmanager moves current process in a specific namespace and
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ensures to move it back in original namespace or kills it if we fail to
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move back in original namespace.
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"""
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if not namespace:
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yield
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return
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org_netns_fd = os.open(PROCESS_NETNS, os.O_RDONLY)
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pynetns.setns(namespace)
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try:
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yield
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finally:
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try:
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# NOTE(cby): this code is not executed only if we fail to
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# move in target namespace
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pynetns.setns(org_netns_fd)
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except Exception as e:
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msg = _('Failed to move back in original netns: %s') % e
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LOG.critical(msg)
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raise BackInNamespaceExit(msg)
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