zun/higgins/common/rpc_service.py
Namrata 429942ce55 Add RPC server code for Higgins
This patch adds RPC code for Higgins to execute
various RPC operations.

Change-Id: If302293788bd4ba8bbdfe063711cc8978d909ec3
Implements: blueprint add-rpc-server-code
2016-05-20 13:29:16 +05:30

100 lines
3.5 KiB
Python

# Copyright 2014 - Rackspace Hosting
#
# 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.
"""Common RPC service and API tools for Higgins."""
import eventlet
from oslo_config import cfg
import oslo_messaging as messaging
from oslo_service import service
from higgins.common import rpc
from higgins.objects import base as objects_base
# NOTE(paulczar):
# Ubuntu 14.04 forces librabbitmq when kombu is used
# Unfortunately it forces a version that has a crash
# bug. Calling eventlet.monkey_patch() tells kombu
# to use libamqp instead.
eventlet.monkey_patch()
# NOTE(asalkeld):
# The higgins.openstack.common.rpc entries are for compatibility
# with devstack rpc_backend configuration values.
TRANSPORT_ALIASES = {
'higgins.openstack.common.rpc.impl_kombu': 'rabbit',
'higgins.openstack.common.rpc.impl_qpid': 'qpid',
'higgins.openstack.common.rpc.impl_zmq': 'zmq',
}
CONF = cfg.CONF
class Service(service.Service):
def __init__(self, topic, server, handlers, binary):
super(Service, self).__init__()
serializer = rpc.RequestContextSerializer(
objects_base.HigginsObjectSerializer())
transport = messaging.get_transport(cfg.CONF,
aliases=TRANSPORT_ALIASES)
# TODO(asalkeld) add support for version='x.y'
target = messaging.Target(topic=topic, server=server)
self._server = messaging.get_rpc_server(transport, target, handlers,
serializer=serializer)
self.binary = binary
def start(self):
self._server.start()
def stop(self):
if self._server:
self._server.stop()
self._server.wait()
super(Service, self).stop()
@classmethod
def create(cls, topic, server, handlers, binary):
service_obj = cls(topic, server, handlers, binary)
return service_obj
class API(object):
def __init__(self, transport=None, context=None, topic=None, server=None,
timeout=None):
serializer = rpc.RequestContextSerializer(
objects_base.HigginsObjectSerializer())
if transport is None:
exmods = rpc.get_allowed_exmods()
transport = messaging.get_transport(cfg.CONF,
allowed_remote_exmods=exmods,
aliases=TRANSPORT_ALIASES)
self._context = context
if topic is None:
topic = ''
target = messaging.Target(topic=topic, server=server)
self._client = messaging.RPCClient(transport, target,
serializer=serializer,
timeout=timeout)
def _call(self, method, *args, **kwargs):
return self._client.call(self._context, method, *args, **kwargs)
def _cast(self, method, *args, **kwargs):
self._client.cast(self._context, method, *args, **kwargs)
def echo(self, message):
self._cast('echo', message=message)