98 lines
3.2 KiB
Python
98 lines
3.2 KiB
Python
# 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.
|
|
|
|
from oslo_context import context as oslo_context
|
|
from oslo_log import log as logging
|
|
import oslo_messaging
|
|
from oslo_service import service
|
|
|
|
from evoque.common import consts
|
|
from evoque.common import messaging as rpc_messaging
|
|
from evoque.i18n import _LI
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
OPERATIONS = (
|
|
START_ACTION, CANCEL_ACTION, STOP
|
|
) = (
|
|
'start_action', 'cancel_action', 'stop'
|
|
)
|
|
|
|
|
|
class Dispatcher(service.Service):
|
|
'''Listen on an AMQP queue named for the engine.
|
|
|
|
Receive notification from engine services and schedule actions.
|
|
'''
|
|
def __init__(self, engine_service, topic, version, thread_group_mgr):
|
|
super(Dispatcher, self).__init__()
|
|
self.TG = thread_group_mgr
|
|
self.engine_id = engine_service.engine_id
|
|
self.topic = topic
|
|
self.version = version
|
|
|
|
def start(self):
|
|
super(Dispatcher, self).start()
|
|
self.target = oslo_messaging.Target(server=self.engine_id,
|
|
topic=self.topic,
|
|
version=self.version)
|
|
server = rpc_messaging.get_rpc_server(self.target, self)
|
|
server.start()
|
|
|
|
def listening(self, ctxt):
|
|
'''Respond affirmatively to confirm that engine is still alive.'''
|
|
return True
|
|
|
|
def stop(self):
|
|
super(Dispatcher, self).stop()
|
|
# Wait for all action threads to be finished
|
|
LOG.info(_LI("Stopping all action threads of engine %s"),
|
|
self.engine_id)
|
|
# Stop ThreadGroup gracefully
|
|
self.TG.stop(True)
|
|
LOG.info(_LI("All action threads have been finished"))
|
|
|
|
|
|
def notify(method, engine_id=None, **kwargs):
|
|
'''Send notification to dispatcher
|
|
|
|
:param method: remote method to call
|
|
:param engine_id: dispatcher to notify; None implies broadcast
|
|
'''
|
|
|
|
client = rpc_messaging.get_rpc_client(version=consts.RPC_API_VERSION)
|
|
|
|
if engine_id:
|
|
# Notify specific dispatcher identified by engine_id
|
|
call_context = client.prepare(
|
|
version=consts.RPC_API_VERSION,
|
|
topic=consts.ENGINE_DISPATCHER_TOPIC,
|
|
server=engine_id)
|
|
else:
|
|
# Broadcast to all disptachers
|
|
call_context = client.prepare(
|
|
version=consts.RPC_API_VERSION,
|
|
topic=consts.ENGINE_DISPATCHER_TOPIC)
|
|
|
|
try:
|
|
# We don't use ctext parameter in action progress
|
|
# actually. But since RPCClient.call needs this param,
|
|
# we use oslo current context here.
|
|
call_context.call(oslo_context.get_current(), method, **kwargs)
|
|
return True
|
|
except oslo_messaging.MessagingTimeout:
|
|
return False
|
|
|
|
|
|
def start_action(engine_id=None, **kwargs):
|
|
return notify(START_ACTION, engine_id, **kwargs)
|