oslo.messaging/openstack/common/messaging/transport.py

83 lines
2.8 KiB
Python

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
# Copyright 2013 Red Hat, Inc.
#
# 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.
import urlparse
from oslo.config import cfg
from stevedore import driver
from openstack.common.messaging import drivers
_transport_opts = [
cfg.StrOpt('transport_url',
default=None,
help='A URL representing the messaging driver to use and its '
'full configuration. If not set, we fall back to the '
'rpc_backend option and driver specific configuration.'),
cfg.StrOpt('rpc_backend',
default='kombu',
help='The messaging driver to use, defaults to kombu. Other '
'drivers include qpid and zmq.'),
cfg.StrOpt('control_exchange',
default='openstack',
help='The default exchange under which topics are scoped. May '
'be overridden by an exchange name specified in the '
'transport_url option.'),
]
def set_defaults(control_exchange):
cfg.set_defaults(_transport_opts,
control_exchange=control_exchange)
class Transport(object):
def __init__(self, driver):
self.conf = driver.conf
self._driver = driver
def send(self, target, message, wait_for_reply=None, timeout=None):
return self._driver._send(target, message,
wait_for_reply=wait_for_reply,
timeout=timeout)
def listen(self, target):
return self._driver._listen(target)
def get_transport(conf, url=None):
conf.register_opts(_transport_opts)
url = url or conf.transport_url
if url is not None:
rpc_backend = urlparse.urlparse(url).scheme
else:
rpc_backend = conf.rpc_backend
kwargs = dict(default_exchange=conf.control_exchange)
if url is not None:
kwargs['url'] = url
mgr = driver.DriverManager(drivers.NAMESPACE,
rpc_backend,
invoke_on_load=True,
invoke_args=[conf],
invoke_kwds=kwargs)
return Transport(mgr.driver)