17bf3db06a
Remove line containing comment - # vim: tabstop=4 shiftwidth=4 softtabstop=4 Change-Id: I7581cc88b8de433d5609ed06c6570b0b45c13573 Closes-Bug:#1229324
149 lines
5.1 KiB
Python
149 lines
5.1 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright (C) 2013 Yahoo! Inc. 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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from __future__ import absolute_import
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import abc
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import logging
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import six
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from taskflow.openstack.common import excutils
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from taskflow import states
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from taskflow.utils import misc
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LOG = logging.getLogger(__name__)
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# NOTE(harlowja): on these states will results be usable, all other states
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# do not produce results.
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FINISH_STATES = (states.FAILURE, states.SUCCESS)
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class ListenerBase(object):
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"""This provides a simple listener that can be attached to an engine which
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can be derived from to do some action on various flow and task state
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transitions. It provides a useful context manager access to be able to
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register and unregister with a given engine automatically when a context
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is entered and when it is exited.
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"""
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def __init__(self, engine,
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task_listen_for=(misc.TransitionNotifier.ANY,),
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flow_listen_for=(misc.TransitionNotifier.ANY,)):
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if not task_listen_for:
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task_listen_for = []
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if not flow_listen_for:
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flow_listen_for = []
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self._listen_for = {
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'task': list(task_listen_for),
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'flow': list(flow_listen_for),
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}
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self._engine = engine
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self._registered = False
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def _flow_receiver(self, state, details):
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pass
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def _task_receiver(self, state, details):
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pass
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def deregister(self):
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if not self._registered:
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return
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def _deregister(watch_states, notifier, cb):
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for s in watch_states:
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notifier.deregister(s, cb)
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_deregister(self._listen_for['task'], self._engine.task_notifier,
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self._task_receiver)
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_deregister(self._listen_for['flow'], self._engine.notifier,
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self._flow_receiver)
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self._registered = False
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def register(self):
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if self._registered:
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return
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def _register(watch_states, notifier, cb):
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registered = []
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try:
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for s in watch_states:
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if not notifier.is_registered(s, cb):
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notifier.register(s, cb)
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registered.append((s, cb))
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except ValueError:
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with excutils.save_and_reraise_exception():
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for (s, cb) in registered:
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notifier.deregister(s, cb)
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_register(self._listen_for['task'], self._engine.task_notifier,
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self._task_receiver)
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_register(self._listen_for['flow'], self._engine.notifier,
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self._flow_receiver)
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self._registered = True
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def __enter__(self):
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self.register()
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def __exit__(self, type, value, tb):
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try:
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self.deregister()
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except Exception:
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# Don't let deregistering throw exceptions
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LOG.exception("Failed deregistering listeners from engine %s",
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self._engine)
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@six.add_metaclass(abc.ABCMeta)
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class LoggingBase(ListenerBase):
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"""This provides a simple listener that can be attached to an engine which
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can be derived from to log the received actions to some logging backend. It
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provides a useful context manager access to be able to register and
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unregister with a given engine automatically when a context is entered and
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when it is exited.
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"""
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@abc.abstractmethod
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def _log(self, message, *args, **kwargs):
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raise NotImplementedError()
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def _flow_receiver(self, state, details):
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self._log("%s has moved flow '%s' (%s) into state '%s'",
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self._engine, details['flow_name'],
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details['flow_uuid'], state)
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def _task_receiver(self, state, details):
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if state in FINISH_STATES:
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result = details.get('result')
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exc_info = None
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was_failure = False
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if isinstance(result, misc.Failure):
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if result.exc_info:
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exc_info = tuple(result.exc_info)
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was_failure = True
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self._log("%s has moved task '%s' (%s) into state '%s'"
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" with result '%s' (failure=%s)",
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self._engine, details['task_name'],
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details['task_uuid'], state, result, was_failure,
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exc_info=exc_info)
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else:
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self._log("%s has moved task '%s' (%s) into state '%s'",
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self._engine, details['task_name'],
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details['task_uuid'], state)
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