karbor/karbor/rpc.py
chenying 2f529a62bf Short-circuit notifications when not enabled
In Mitaka oslo messaging introduced the transport_url specific for
notifications under the oslo_messaging_notifications section, but some
projects still use the default transport_url defined in the DEFAULT
section. Use messaging notifications transport instead of default.

This patch proposes short-circuiting notification methods as much as
possible to optimize code execution when Karbor has no notification
transport mechanism configured.

The NOTIFIER only be inited only if notifications are actually
enabled.

Change-Id: Id9419ddd801bf9d8ac13c4a73a91e39fd763cb2b
Closes-Bug: #1719786
2017-09-29 14:17:45 +08:00

145 lines
4.2 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.
__all__ = [
'init',
'cleanup',
'set_defaults',
'add_extra_exmods',
'clear_extra_exmods',
'get_allowed_exmods',
'RequestContextSerializer',
'get_client',
'get_server',
'get_notifier',
]
from oslo_config import cfg
import oslo_messaging as messaging
from oslo_messaging.rpc import dispatcher
import karbor.context
import karbor.exception
from karbor import utils
CONF = cfg.CONF
TRANSPORT = None
NOTIFICATION_TRANSPORT = None
NOTIFIER = None
ALLOWED_EXMODS = [
karbor.exception.__name__,
]
EXTRA_EXMODS = []
def init(conf):
global TRANSPORT, NOTIFICATION_TRANSPORT, NOTIFIER
exmods = get_allowed_exmods()
TRANSPORT = messaging.get_rpc_transport(conf,
allowed_remote_exmods=exmods)
NOTIFICATION_TRANSPORT = messaging.get_notification_transport(
conf,
allowed_remote_exmods=exmods)
# get_notification_transport has loaded oslo_messaging_notifications config
# group, so we can now check if notifications are actually enabled.
if utils.notifications_enabled(conf):
json_serializer = messaging.JsonPayloadSerializer()
serializer = RequestContextSerializer(json_serializer)
NOTIFIER = messaging.Notifier(NOTIFICATION_TRANSPORT,
serializer=serializer)
else:
NOTIFIER = utils.DO_NOTHING
def initialized():
return None not in [TRANSPORT, NOTIFIER]
def cleanup():
global TRANSPORT, NOTIFICATION_TRANSPORT, NOTIFIER
assert TRANSPORT is not None
TRANSPORT.cleanup()
NOTIFICATION_TRANSPORT.cleanup()
TRANSPORT = NOTIFICATION_TRANSPORT = NOTIFIER = None
def set_defaults(control_exchange):
messaging.set_transport_defaults(control_exchange)
def add_extra_exmods(*args):
EXTRA_EXMODS.extend(args)
def clear_extra_exmods():
del EXTRA_EXMODS[:]
def get_allowed_exmods():
return ALLOWED_EXMODS + EXTRA_EXMODS
class RequestContextSerializer(messaging.Serializer):
def __init__(self, base):
self._base = base
super(RequestContextSerializer, self).__init__()
def serialize_entity(self, context, entity):
if not self._base:
return entity
return self._base.serialize_entity(context, entity)
def deserialize_entity(self, context, entity):
if not self._base:
return entity
return self._base.deserialize_entity(context, entity)
def serialize_context(self, context):
_context = context.to_dict()
return _context
def deserialize_context(self, context):
return karbor.context.RequestContext.from_dict(context)
def get_client(target, version_cap=None, serializer=None):
assert TRANSPORT is not None
serializer = RequestContextSerializer(serializer)
return messaging.RPCClient(TRANSPORT,
target,
version_cap=version_cap,
serializer=serializer)
def get_server(target, endpoints, serializer=None):
assert TRANSPORT is not None
serializer = RequestContextSerializer(serializer)
access_policy = dispatcher.DefaultRPCAccessPolicy
return messaging.get_rpc_server(TRANSPORT,
target,
endpoints,
executor='eventlet',
serializer=serializer,
access_policy=access_policy)
def get_notifier(service=None, host=None, publisher_id=None):
assert NOTIFIER is not None
if not publisher_id:
publisher_id = "%s.%s" % (service, host or CONF.host)
return NOTIFIER.prepare(publisher_id=publisher_id)