112 lines
3.6 KiB
Python
112 lines
3.6 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
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#
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# Copyright 2012 New Dream Network, LLC (DreamHost)
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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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#
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# @author: Mark McClain, DreamHost
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import os
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from quantum.agent.linux import ip_lib
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from quantum.agent.linux import utils
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from quantum.openstack.common import cfg
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from quantum.openstack.common import log as logging
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LOG = logging.getLogger(__name__)
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OPTS = [
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cfg.StrOpt('external_pids',
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default='$state_path/external/pids',
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help=_('Location to store child pid files')),
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]
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cfg.CONF.register_opts(OPTS)
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class ProcessManager(object):
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"""An external process manager for Quantum spawned processes.
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Note: The manager expects uuid to be in cmdline.
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"""
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def __init__(self, conf, uuid, root_helper='sudo', namespace=None):
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self.conf = conf
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self.uuid = uuid
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self.root_helper = root_helper
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self.namespace = namespace
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def enable(self, cmd_callback):
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if not self.active:
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cmd = cmd_callback(self.get_pid_file_name(ensure_pids_dir=True))
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if self.namespace:
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ip_wrapper = ip_lib.IPWrapper(self.root_helper, self.namespace)
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ip_wrapper.netns.execute(cmd)
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else:
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# For normal sudo prepend the env vars before command
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utils.execute(cmd, self.root_helper)
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def disable(self):
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pid = self.pid
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if self.active:
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cmd = ['kill', '-9', pid]
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if self.namespace:
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ip_wrapper = ip_lib.IPWrapper(self.root_helper, self.namespace)
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ip_wrapper.netns.execute(cmd)
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else:
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utils.execute(cmd, self.root_helper)
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elif pid:
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LOG.debug(_('Process for %(uuid)s pid %(pid)d is stale, ignoring '
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'command'), {'uuid': self.uuid, 'pid': pid})
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else:
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LOG.debug(_('No process started for %s'), self.uuid)
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def get_pid_file_name(self, ensure_pids_dir=False):
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"""Returns the file name for a given kind of config file."""
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pids_dir = os.path.abspath(os.path.normpath(self.conf.external_pids))
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if ensure_pids_dir and not os.path.isdir(pids_dir):
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os.makedirs(pids_dir, 0755)
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return os.path.join(pids_dir, self.uuid + '.pid')
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@property
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def pid(self):
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"""Last known pid for this external process spawned for this uuid."""
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file_name = self.get_pid_file_name()
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msg = _('Error while reading %s')
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try:
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with open(file_name, 'r') as f:
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return int(f.read())
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except IOError, e:
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msg = _('Unable to access %s')
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except ValueError, e:
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msg = _('Unable to convert value in %s')
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LOG.debug(msg, file_name)
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return None
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@property
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def active(self):
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pid = self.pid
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if pid is None:
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return False
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cmd = ['cat', '/proc/%s/cmdline' % pid]
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try:
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return self.uuid in utils.execute(cmd, self.root_helper)
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except RuntimeError, e:
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return False
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