OpenStack library for messaging
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# Copyright 2011 Cloudscaling Group, 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 collections
import logging
import os
import pprint
import re
import socket
import sys
import threading
import types
import uuid
import eventlet
import greenlet
import six
from six import moves
from oslo.config import cfg
from oslo.messaging._drivers import base
from oslo.messaging._drivers import common as rpc_common
from oslo.messaging._executors import impl_eventlet # FIXME(markmc)
from oslo.messaging.openstack.common.gettextutils import _
from oslo.messaging.openstack.common import jsonutils
from oslo.utils import excutils
from oslo.utils import importutils
zmq = importutils.try_import('eventlet.green.zmq')
# for convenience, are not modified.
pformat = pprint.pformat
Timeout = eventlet.timeout.Timeout
LOG = logging.getLogger(__name__)
RPCException = rpc_common.RPCException
zmq_opts = [
cfg.StrOpt('rpc_zmq_bind_address', default='*',
help='ZeroMQ bind address. Should be a wildcard (*), '
'an ethernet interface, or IP. '
'The "host" option should point or resolve to this '
'address.'),
# The module.Class to use for matchmaking.
cfg.StrOpt(
'rpc_zmq_matchmaker',
default=('oslo.messaging._drivers.'
'matchmaker.MatchMakerLocalhost'),
help='MatchMaker driver.',
),
# The following port is unassigned by IANA as of 2012-05-21
cfg.IntOpt('rpc_zmq_port', default=9501,
help='ZeroMQ receiver listening port.'),
cfg.IntOpt('rpc_zmq_contexts', default=1,
help='Number of ZeroMQ contexts, defaults to 1.'),
cfg.IntOpt('rpc_zmq_topic_backlog',
help='Maximum number of ingress messages to locally buffer '
'per topic. Default is unlimited.'),
cfg.StrOpt('rpc_zmq_ipc_dir', default='/var/run/openstack',
help='Directory for holding IPC sockets.'),
cfg.StrOpt('rpc_zmq_host', default=socket.gethostname(),
sample_default='localhost',
help='Name of this node. Must be a valid hostname, FQDN, or '
'IP address. Must match "host" option, if running Nova.'),
cfg.IntOpt('rpc_cast_timeout',
default=30,
help='Seconds to wait before a cast expires (TTL). '
'Only supported by impl_zmq.'),
]
CONF = cfg.CONF
ZMQ_CTX = None # ZeroMQ Context, must be global.
matchmaker = None # memoized matchmaker object
def _serialize(data):
"""Serialization wrapper.
We prefer using JSON, but it cannot encode all types.
Error if a developer passes us bad data.
"""
try:
return jsonutils.dumps(data, ensure_ascii=True)
except TypeError:
with excutils.save_and_reraise_exception():
LOG.error(_("JSON serialization failed."))
def _deserialize(data):
"""Deserialization wrapper."""
LOG.debug("Deserializing: %s", data)
return jsonutils.loads(data)
class ZmqSocket(object):
"""A tiny wrapper around ZeroMQ.
Simplifies the send/recv protocol and connection management.
Can be used as a Context (supports the 'with' statement).
"""
def __init__(self, addr, zmq_type, bind=True, subscribe=None):
self.sock = _get_ctxt().socket(zmq_type)
self.addr = addr
self.type = zmq_type
self.subscriptions = []
# Support failures on sending/receiving on wrong socket type.
self.can_recv = zmq_type in (zmq.PULL, zmq.SUB)
self.can_send = zmq_type in (zmq.PUSH, zmq.PUB)
self.can_sub = zmq_type in (zmq.SUB, )
# Support list, str, & None for subscribe arg (cast to list)
do_sub = {
list: subscribe,
str: [subscribe],
type(None): []
}[type(subscribe)]
for f in do_sub:
self.subscribe(f)
str_data = {'addr': addr, 'type': self.socket_s(),
'subscribe': subscribe, 'bind': bind}
LOG.debug("Connecting to %(addr)s with %(type)s", str_data)
LOG.debug("-> Subscribed to %(subscribe)s", str_data)
LOG.debug("-> bind: %(bind)s", str_data)
try:
if bind:
self.sock.bind(addr)
else:
self.sock.connect(addr)
except Exception:
raise RPCException(_("Could not open socket."))
def socket_s(self):
"""Get socket type as string."""
t_enum = ('PUSH', 'PULL', 'PUB', 'SUB', 'REP', 'REQ', 'ROUTER',
'DEALER')
return dict(map(lambda t: (getattr(zmq, t), t), t_enum))[self.type]
def subscribe(self, msg_filter):
"""Subscribe."""
if not self.can_sub:
raise RPCException("Cannot subscribe on this socket.")
LOG.debug("Subscribing to %s", msg_filter)
try:
self.sock.setsockopt(zmq.SUBSCRIBE, msg_filter)
except Exception:
return
self.subscriptions.append(msg_filter)
def unsubscribe(self, msg_filter):
"""Unsubscribe."""
if msg_filter not in self.subscriptions:
return
self.sock.setsockopt(zmq.UNSUBSCRIBE, msg_filter)
self.subscriptions.remove(msg_filter)
def close(self):
if self.sock is None or self.sock.closed:
return
# We must unsubscribe, or we'll leak descriptors.
if self.subscriptions:
for f in self.subscriptions:
try:
self.sock.setsockopt(zmq.UNSUBSCRIBE, f)
except Exception:
pass
self.subscriptions = []
try:
# Default is to linger
self.sock.close()
except Exception:
# While this is a bad thing to happen,
# it would be much worse if some of the code calling this
# were to fail. For now, lets log, and later evaluate
# if we can safely raise here.
LOG.error("ZeroMQ socket could not be closed.")
self.sock = None
def recv(self, **kwargs):
if not self.can_recv:
raise RPCException(_("You cannot recv on this socket."))
return self.sock.recv_multipart(**kwargs)
def send(self, data, **kwargs):
if not self.can_send:
raise RPCException(_("You cannot send on this socket."))
self.sock.send_multipart(data, **kwargs)
class ZmqClient(object):
"""Client for ZMQ sockets."""
def __init__(self, addr):
self.outq = ZmqSocket(addr, zmq.PUSH, bind=False)
def cast(self, msg_id, topic, data, envelope):
msg_id = msg_id or 0
if not envelope:
self.outq.send(map(bytes,
(msg_id, topic, 'cast', _serialize(data))))
return
rpc_envelope = rpc_common.serialize_msg(data[1])
zmq_msg = moves.reduce(lambda x, y: x + y, rpc_envelope.items())
self.outq.send(map(bytes,
(msg_id, topic, 'impl_zmq_v2', data[0]) + zmq_msg))
def close(self):
self.outq.close()
class RpcContext(rpc_common.CommonRpcContext):
"""Context that supports replying to a rpc.call."""
def __init__(self, **kwargs):
self.replies = []
super(RpcContext, self).__init__(**kwargs)
def deepcopy(self):
values = self.to_dict()
values['replies'] = self.replies
return self.__class__(**values)
def reply(self, reply=None, failure=None, ending=False):
if ending:
return
self.replies.append(reply)
@classmethod
def marshal(self, ctx):
ctx_data = ctx.to_dict()
return _serialize(ctx_data)
@classmethod
def unmarshal(self, data):
return RpcContext.from_dict(_deserialize(data))
class InternalContext(object):
"""Used by ConsumerBase as a private context for - methods."""
def __init__(self, proxy):
self.proxy = proxy
self.msg_waiter = None
def _get_response(self, ctx, proxy, topic, data):
"""Process a curried message and cast the result to topic."""
LOG.debug("Running func with context: %s", ctx.to_dict())
data.setdefault('version', None)
data.setdefault('args', {})
try:
result = proxy.dispatch(
ctx, data['version'], data['method'],
data.get('namespace'), **data['args'])
return ConsumerBase.normalize_reply(result, ctx.replies)
except greenlet.GreenletExit:
# ignore these since they are just from shutdowns
pass
except rpc_common.ClientException as e:
LOG.debug("Expected exception during message handling (%s)",
e._exc_info[1])
return {'exc':
rpc_common.serialize_remote_exception(e._exc_info,
log_failure=False)}
except Exception:
LOG.error(_("Exception during message handling"))
return {'exc':
rpc_common.serialize_remote_exception(sys.exc_info())}
def reply(self, ctx, proxy,
msg_id=None, context=None, topic=None, msg=None):
"""Reply to a casted call."""
# NOTE(ewindisch): context kwarg exists for Grizzly compat.
# this may be able to be removed earlier than
# 'I' if ConsumerBase.process were refactored.
if type(msg) is list:
payload = msg[-1]
else:
payload = msg
response = ConsumerBase.normalize_reply(
self._get_response(ctx, proxy, topic, payload),
ctx.replies)
LOG.debug("Sending reply")
_multi_send(_cast, ctx, topic, {
'method': '-process_reply',
'args': {
'msg_id': msg_id, # Include for Folsom compat.
'response': response
}
}, _msg_id=msg_id)
class ConsumerBase(object):
"""Base Consumer."""
def __init__(self):
self.private_ctx = InternalContext(None)
@classmethod
def normalize_reply(self, result, replies):
# TODO(ewindisch): re-evaluate and document this method.
if isinstance(result, types.GeneratorType):
return list(result)
elif replies:
return replies
else:
return [result]
def process(self, proxy, ctx, data):
data.setdefault('version', None)
data.setdefault('args', {})
# Method starting with - are
# processed internally. (non-valid method name)
method = data.get('method')
if not method:
LOG.error(_("RPC message did not include method."))
return
# Internal method
# uses internal context for safety.
if method == '-reply':
self.private_ctx.reply(ctx, proxy, **data['args'])
return
proxy.dispatch(ctx, data['version'],
data['method'], data.get('namespace'), **data['args'])
class ZmqBaseReactor(ConsumerBase):
"""A consumer class implementing a centralized casting broker (PULL-PUSH).
Used for RoundRobin requests.
"""
def __init__(self, conf):
super(ZmqBaseReactor, self).__init__()
self.proxies = {}
self.threads = []
self.sockets = []
self.subscribe = {}
self.pool = eventlet.greenpool.GreenPool(conf.rpc_thread_pool_size)
def register(self, proxy, in_addr, zmq_type_in,
in_bind=True, subscribe=None):
LOG.info(_("Registering reactor"))
if zmq_type_in not in (zmq.PULL, zmq.SUB):
raise RPCException("Bad input socktype")
# Items push in.
inq = ZmqSocket(in_addr, zmq_type_in, bind=in_bind,
subscribe=subscribe)
self.proxies[inq] = proxy
self.sockets.append(inq)
LOG.info(_("In reactor registered"))
def consume_in_thread(self):
def _consume(sock):
LOG.info(_("Consuming socket"))
while True:
self.consume(sock)
for k in self.proxies.keys():
self.threads.append(
self.pool.spawn(_consume, k)
)
def wait(self):
for t in self.threads:
t.wait()
def close(self):
for s in self.sockets:
s.close()
for t in self.threads:
t.kill()
class ZmqProxy(ZmqBaseReactor):
"""A consumer class implementing a topic-based proxy.
Forwards to IPC sockets.
"""
def __init__(self, conf):
super(ZmqProxy, self).__init__(conf)
pathsep = set((os.path.sep or '', os.path.altsep or '', '/', '\\'))
self.badchars = re.compile(r'[%s]' % re.escape(''.join(pathsep)))
self.topic_proxy = {}
def consume(self, sock):
ipc_dir = CONF.rpc_zmq_ipc_dir
data = sock.recv(copy=False)
topic = data[1].bytes
if topic.startswith('fanout~'):
sock_type = zmq.PUB
topic = topic.split('.', 1)[0]
elif topic.startswith('zmq_replies'):
sock_type = zmq.PUB
else:
sock_type = zmq.PUSH
if topic not in self.topic_proxy:
def publisher(waiter):
LOG.info(_("Creating proxy for topic: %s"), topic)
try:
# The topic is received over the network,
# don't trust this input.
if self.badchars.search(topic) is not None:
emsg = _("Topic contained dangerous characters.")
LOG.warn(emsg)
raise RPCException(emsg)
out_sock = ZmqSocket("ipc://%s/zmq_topic_%s" %
(ipc_dir, topic),
sock_type, bind=True)
except RPCException:
waiter.send_exception(*sys.exc_info())
return
self.topic_proxy[topic] = eventlet.queue.LightQueue(
CONF.rpc_zmq_topic_backlog)
self.sockets.append(out_sock)
# It takes some time for a pub socket to open,
# before we can have any faith in doing a send() to it.
if sock_type == zmq.PUB:
eventlet.sleep(.5)
waiter.send(True)
while(True):
data = self.topic_proxy[topic].get()
out_sock.send(data, copy=False)
wait_sock_creation = eventlet.event.Event()
eventlet.spawn(publisher, wait_sock_creation)
try:
wait_sock_creation.wait()
except RPCException:
LOG.error(_("Topic socket file creation failed."))
return
try:
self.topic_proxy[topic].put_nowait(data)
except eventlet.queue.Full:
LOG.error(_("Local per-topic backlog buffer full for topic "
"%s. Dropping message."), topic)
def consume_in_thread(self):
"""Runs the ZmqProxy service."""
ipc_dir = CONF.rpc_zmq_ipc_dir
consume_in = "tcp://%s:%s" % \
(CONF.rpc_zmq_bind_address,
CONF.rpc_zmq_port)
consumption_proxy = InternalContext(None)
try:
os.makedirs(ipc_dir)
except os.error:
if not os.path.isdir(ipc_dir):
with excutils.save_and_reraise_exception():
LOG.error(_("Required IPC directory does not exist at"
" %s"), ipc_dir)
try:
self.register(consumption_proxy,
consume_in,
zmq.PULL)
except zmq.ZMQError:
if os.access(ipc_dir, os.X_OK):
with excutils.save_and_reraise_exception():
LOG.error(_("Permission denied to IPC directory at"
" %s"), ipc_dir)
with excutils.save_and_reraise_exception():
LOG.error(_("Could not create ZeroMQ receiver daemon. "
"Socket may already be in use."))
super(ZmqProxy, self).consume_in_thread()
def unflatten_envelope(packenv):
"""Unflattens the RPC envelope.
Takes a list and returns a dictionary.
i.e. [1,2,3,4] => {1: 2, 3: 4}
"""
i = iter(packenv)
h = {}
try:
while True:
k = six.next(i)
h[k] = six.next(i)
except StopIteration:
return h
class ZmqReactor(ZmqBaseReactor):
"""A consumer class implementing a consumer for messages.
Can also be used as a 1:1 proxy
"""
def __init__(self, conf):
super(ZmqReactor, self).__init__(conf)
def consume(self, sock):
# TODO(ewindisch): use zero-copy (i.e. references, not copying)
data = sock.recv()
LOG.debug("CONSUMER RECEIVED DATA: %s", data)
proxy = self.proxies[sock]
if data[2] == 'cast': # Legacy protocol
packenv = data[3]
ctx, msg = _deserialize(packenv)
request = rpc_common.deserialize_msg(msg)
ctx = RpcContext.unmarshal(ctx)
elif data[2] == 'impl_zmq_v2':
packenv = data[4:]
msg = unflatten_envelope(packenv)
request = rpc_common.deserialize_msg(msg)
# Unmarshal only after verifying the message.
ctx = RpcContext.unmarshal(data[3])
else:
LOG.error(_("ZMQ Envelope version unsupported or unknown."))
return
self.pool.spawn_n(self.process, proxy, ctx, request)
class Connection(rpc_common.Connection):
"""Manages connections and threads."""
def __init__(self, conf):
self.topics = []
self.reactor = ZmqReactor(conf)
def create_consumer(self, topic, proxy, fanout=False):
# Register with matchmaker.
_get_matchmaker().register(topic, CONF.rpc_zmq_host)
# Subscription scenarios
if fanout:
sock_type = zmq.SUB
subscribe = ('', fanout)[type(fanout) == str]
topic = 'fanout~' + topic.split('.', 1)[0]
else:
sock_type = zmq.PULL
subscribe = None
topic = '.'.join((topic.split('.', 1)[0], CONF.rpc_zmq_host))
if topic in self.topics:
LOG.info(_("Skipping topic registration. Already registered."))
return
# Receive messages from (local) proxy
inaddr = "ipc://%s/zmq_topic_%s" % \
(CONF.rpc_zmq_ipc_dir, topic)
LOG.debug("Consumer is a zmq.%s",
['PULL', 'SUB'][sock_type == zmq.SUB])
self.reactor.register(proxy, inaddr, sock_type,
subscribe=subscribe, in_bind=False)
self.topics.append(topic)
def close(self):
_get_matchmaker().stop_heartbeat()
for topic in self.topics:
_get_matchmaker().unregister(topic, CONF.rpc_zmq_host)
self.reactor.close()
self.topics = []
def wait(self):
self.reactor.wait()
def consume_in_thread(self):
_get_matchmaker().start_heartbeat()
self.reactor.consume_in_thread()
def _cast(addr, context, topic, msg, timeout=None, envelope=False,
_msg_id=None, allowed_remote_exmods=None):
allowed_remote_exmods = allowed_remote_exmods or []
timeout_cast = timeout or CONF.rpc_cast_timeout
payload = [RpcContext.marshal(context), msg]
with Timeout(timeout_cast, exception=rpc_common.Timeout):
try:
conn = ZmqClient(addr)
# assumes cast can't return an exception
conn.cast(_msg_id, topic, payload, envelope)
except zmq.ZMQError:
raise RPCException("Cast failed. ZMQ Socket Exception")
finally:
if 'conn' in vars():
conn.close()
def _call(addr, context, topic, msg, timeout=None,
envelope=False, allowed_remote_exmods=None):
allowed_remote_exmods = allowed_remote_exmods or []
# timeout_response is how long we wait for a response
timeout = timeout or CONF.rpc_response_timeout
# The msg_id is used to track replies.
msg_id = uuid.uuid4().hex
# Replies always come into the reply service.
reply_topic = "zmq_replies.%s" % CONF.rpc_zmq_host
LOG.debug("Creating payload")
# Curry the original request into a reply method.
mcontext = RpcContext.marshal(context)
payload = {
'method': '-reply',
'args': {
'msg_id': msg_id,
'topic': reply_topic,
# TODO(ewindisch): safe to remove mcontext in I.
'msg': [mcontext, msg]
}
}
LOG.debug("Creating queue socket for reply waiter")
# Messages arriving async.
# TODO(ewindisch): have reply consumer with dynamic subscription mgmt
with Timeout(timeout, exception=rpc_common.Timeout):
try:
msg_waiter = ZmqSocket(
"ipc://%s/zmq_topic_zmq_replies.%s" %
(CONF.rpc_zmq_ipc_dir,
CONF.rpc_zmq_host),
zmq.SUB, subscribe=msg_id, bind=False
)
LOG.debug("Sending cast")
_cast(addr, context, topic, payload, envelope=envelope)
LOG.debug("Cast sent; Waiting reply")
# Blocks until receives reply
msg = msg_waiter.recv()
LOG.debug("Received message: %s", msg)
LOG.debug("Unpacking response")
if msg[2] == 'cast': # Legacy version
raw_msg = _deserialize(msg[-1])[-1]
elif msg[2] == 'impl_zmq_v2':
rpc_envelope = unflatten_envelope(msg[4:])
raw_msg = rpc_common.deserialize_msg(rpc_envelope)
else:
raise rpc_common.UnsupportedRpcEnvelopeVersion(
_("Unsupported or unknown ZMQ envelope returned."))
responses = raw_msg['args']['response']
# ZMQError trumps the Timeout error.
except zmq.ZMQError:
raise RPCException("ZMQ Socket Error")
except (IndexError, KeyError):
raise RPCException(_("RPC Message Invalid."))
finally:
if 'msg_waiter' in vars():
msg_waiter.close()
# It seems we don't need to do all of the following,
# but perhaps it would be useful for multicall?
# One effect of this is that we're checking all
# responses for Exceptions.
for resp in responses:
if isinstance(resp, types.DictType) and 'exc' in resp:
raise rpc_common.deserialize_remote_exception(
resp['exc'], allowed_remote_exmods)
return responses[-1]
def _multi_send(method, context, topic, msg, timeout=None,
envelope=False, _msg_id=None, allowed_remote_exmods=None):
"""Wraps the sending of messages.
Dispatches to the matchmaker and sends message to all relevant hosts.
"""
allowed_remote_exmods = allowed_remote_exmods or []
conf = CONF
LOG.debug(' '.join(map(pformat, (topic, msg))))
queues = _get_matchmaker().queues(topic)
LOG.debug("Sending message(s) to: %s", queues)
# Don't stack if we have no matchmaker results
if not queues:
LOG.warn(_("No matchmaker results. Not casting."))
# While not strictly a timeout, callers know how to handle
# this exception and a timeout isn't too big a lie.
raise rpc_common.Timeout(_("No match from matchmaker."))
# This supports brokerless fanout (addresses > 1)
return_val = None
for queue in queues:
_topic, ip_addr = queue
_addr = "tcp://%s:%s" % (ip_addr, conf.rpc_zmq_port)
if method.__name__ == '_cast':
eventlet.spawn_n(method, _addr, context,
_topic, msg, timeout, envelope, _msg_id)
else:
return_val = method(_addr, context, _topic, msg, timeout,
envelope, allowed_remote_exmods)
return return_val
def create_connection(conf, new=True):
return Connection(conf)
def multicall(conf, *args, **kwargs):
"""Multiple calls."""
return _multi_send(_call, *args, **kwargs)
def call(conf, *args, **kwargs):
"""Send a message, expect a response."""
data = _multi_send(_call, *args, **kwargs)
return data[-1]
def cast(conf, *args, **kwargs):
"""Send a message expecting no reply."""
_multi_send(_cast, *args, **kwargs)
def fanout_cast(conf, context, topic, msg, **kwargs):
"""Send a message to all listening and expect no reply."""
# NOTE(ewindisch): fanout~ is used because it avoid splitting on .
# and acts as a non-subtle hint to the matchmaker and ZmqProxy.
_multi_send(_cast, context, 'fanout~' + six.text_type(topic),
msg, **kwargs)
def notify(conf, context, topic, msg, envelope):
"""Send notification event.
Notifications are sent to topic-priority.
This differs from the AMQP drivers which send to topic.priority.
"""
# NOTE(ewindisch): dot-priority in rpc notifier does not
# work with our assumptions.
topic = topic.replace('.', '-')
cast(conf, context, topic, msg, envelope=envelope)
def cleanup():
"""Clean up resources in use by implementation."""
global ZMQ_CTX
if ZMQ_CTX:
ZMQ_CTX.term()
ZMQ_CTX = None
global matchmaker
matchmaker = None
def _get_ctxt():
if not zmq:
raise ImportError("Failed to import eventlet.green.zmq")
global ZMQ_CTX
if not ZMQ_CTX:
ZMQ_CTX = zmq.Context(CONF.rpc_zmq_contexts)
return ZMQ_CTX
def _get_matchmaker(*args, **kwargs):
global matchmaker
if not matchmaker:
mm = CONF.rpc_zmq_matchmaker
if mm.endswith('matchmaker.MatchMakerRing'):
mm.replace('matchmaker', 'matchmaker_ring')
LOG.warn(_('rpc_zmq_matchmaker = %(orig)s is deprecated; use'
' %(new)s instead') % dict(
orig=CONF.rpc_zmq_matchmaker, new=mm))
matchmaker = importutils.import_object(mm, *args, **kwargs)
return matchmaker
class ZmqIncomingMessage(base.IncomingMessage):
ReceivedReply = collections.namedtuple(
'ReceivedReply', ['reply', 'failure', 'log_failure'])
def __init__(self, listener, ctxt, message):
super(ZmqIncomingMessage, self).__init__(listener, ctxt, message)
self.condition = threading.Condition()
self.received = None
def reply(self, reply=None, failure=None, log_failure=True):
self.received = self.ReceivedReply(reply, failure, log_failure)
with self.condition:
self.condition.notify()
def requeue(self):
pass
class ZmqListener(base.Listener):
def __init__(self, driver):
super(ZmqListener, self).__init__(driver)
self.incoming_queue = moves.queue.Queue()
def dispatch(self, ctxt, version, method, namespace, **kwargs):
message = {
'method': method,
'args': kwargs
}
if version:
message['version'] = version
if namespace:
message['namespace'] = namespace
incoming = ZmqIncomingMessage(self,
ctxt.to_dict(),
message)
self.incoming_queue.put(incoming)
with incoming.condition:
incoming.condition.wait()
assert incoming.received
if incoming.received.failure:
raise incoming.received.failure
else:
return incoming.received.reply
def poll(self, timeout=None):
try:
return self.incoming_queue.get(timeout=timeout)
except six.moves.queue.Empty:
# timeout
return None
class ZmqDriver(base.BaseDriver):
# FIXME(markmc): allow this driver to be used without eventlet
def __init__(self, conf, url, default_exchange=None,
allowed_remote_exmods=None):
conf.register_opts(zmq_opts)
conf.register_opts(impl_eventlet._eventlet_opts)
super(ZmqDriver, self).__init__(conf, url, default_exchange,
allowed_remote_exmods)
# FIXME(markmc): handle default_exchange
# FIXME(markmc): handle transport URL
if self._url.hosts:
raise NotImplementedError('The ZeroMQ driver does not yet support '
'transport URLs')
# FIXME(markmc): use self.conf everywhere
if self.conf is not CONF:
raise NotImplementedError('The ZeroMQ driver currently only works '
'with oslo.config.cfg.CONF')
def _send(self, target, ctxt, message,
wait_for_reply=None, timeout=None, envelope=False):
# FIXME(markmc): remove this temporary hack
class Context(object):
def __init__(self, d):
self.d = d
def to_dict(self):
return self.d
context = Context(ctxt)
if wait_for_reply:
method = _call
else:
method = _cast
topic = target.topic
if target.fanout:
# NOTE(ewindisch): fanout~ is used because it avoid splitting on
# and acts as a non-subtle hint to the matchmaker and ZmqProxy.
topic = 'fanout~' + topic
reply = _multi_send(method, context, topic, message,
envelope=envelope,
allowed_remote_exmods=self._allowed_remote_exmods)
if wait_for_reply:
return reply[-1]
def send(self, target, ctxt, message, wait_for_reply=None, timeout=None,
retry=None):
# NOTE(sileht): retry is not implemented because this driver never
# retry anything
return self._send(target, ctxt, message, wait_for_reply, timeout)
def send_notification(self, target, ctxt, message, version, retry=None):
# NOTE(ewindisch): dot-priority in rpc notifier does not
# work with our assumptions.
# NOTE(sileht): retry is not implemented because this driver never
# retry anything
target = target(topic=target.topic.replace('.', '-'))
return self._send(target, ctxt, message, envelope=(version == 2.0))
def listen(self, target):
conn = create_connection(self.conf)
listener = ZmqListener(self)
conn.create_consumer(target.topic, listener)
conn.create_consumer('%s.%s' % (target.topic, target.server),
listener)
conn.create_consumer(target.topic, listener, fanout=True)
conn.consume_in_thread()
return listener
def listen_for_notifications(self, targets_and_priorities):
# NOTE(sileht): this listener implementation is limited
# because zeromq doesn't support requeing message
conn = create_connection(self.conf)
listener = ZmqListener(self, None)
for target, priority in targets_and_priorities:
# NOTE(ewindisch): dot-priority in rpc notifier does not
# work with our assumptions.
# NOTE(sileht): create_consumer doesn't support target.exchange
conn.create_consumer('%s-%s' % (target.topic, priority),
listener)
conn.consume_in_thread()
return listener
def cleanup(self):
cleanup()