openstack
/
oslo.messaging
Code Issues Proposed changes

Add oslo-incubator code unmodified 

I want to make it absolutely clear what changes we're making from the
original driver code, so let's start with a pristine copy.

Change-Id: I38507382b1ce68c7f8f697522f9a1bf00e76532d
This commit is contained in:
Mark McLoughlin 2013-07-23 16:28:15 +01:00
parent 43ab36d1a1
commit e91dbef454
4 changed files with 2723 additions and 0 deletions
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610
oslo/messaging/_drivers/amqp.py Normal file
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
# Copyright 2011 - 2012, 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.
"""
Shared code between AMQP based openstack.common.rpc implementations.
The code in this module is shared between the rpc implemenations based on AMQP.
Specifically, this includes impl_kombu and impl_qpid. impl_carrot also uses
AMQP, but is deprecated and predates this code.
"""
import collections
import inspect
import sys
import uuid
from eventlet import greenpool
from eventlet import pools
from eventlet import queue
from eventlet import semaphore
from oslo.config import cfg
from openstack.common import excutils
from openstack.common.gettextutils import _ # noqa
from openstack.common import local
from openstack.common import log as logging
from openstack.common.rpc import common as rpc_common
amqp_opts = [
cfg.BoolOpt('amqp_durable_queues',
default=False,
deprecated_name='rabbit_durable_queues',
deprecated_group='DEFAULT',
help='Use durable queues in amqp.'),
cfg.BoolOpt('amqp_auto_delete',
default=False,
help='Auto-delete queues in amqp.'),
]
cfg.CONF.register_opts(amqp_opts)
UNIQUE_ID = '_unique_id'
LOG = logging.getLogger(__name__)
class Pool(pools.Pool):
"""Class that implements a Pool of Connections."""
def __init__(self, conf, connection_cls, *args, **kwargs):
self.connection_cls = connection_cls
self.conf = conf
kwargs.setdefault("max_size", self.conf.rpc_conn_pool_size)
kwargs.setdefault("order_as_stack", True)
super(Pool, self).__init__(*args, **kwargs)
self.reply_proxy = None
# TODO(comstud): Timeout connections not used in a while
def create(self):
LOG.debug(_('Pool creating new connection'))
return self.connection_cls(self.conf)
def empty(self):
while self.free_items:
self.get().close()
# Force a new connection pool to be created.
# Note that this was added due to failing unit test cases. The issue
# is the above "while loop" gets all the cached connections from the
# pool and closes them, but never returns them to the pool, a pool
# leak. The unit tests hang waiting for an item to be returned to the
# pool. The unit tests get here via the tearDown() method. In the run
# time code, it gets here via cleanup() and only appears in service.py
# just before doing a sys.exit(), so cleanup() only happens once and
# the leakage is not a problem.
self.connection_cls.pool = None
_pool_create_sem = semaphore.Semaphore()
def get_connection_pool(conf, connection_cls):
with _pool_create_sem:
# Make sure only one thread tries to create the connection pool.
if not connection_cls.pool:
connection_cls.pool = Pool(conf, connection_cls)
return connection_cls.pool
class ConnectionContext(rpc_common.Connection):
"""The class that is actually returned to the create_connection() caller.
This is essentially a wrapper around Connection that supports 'with'.
It can also return a new Connection, or one from a pool.
The function will also catch when an instance of this class is to be
deleted. With that we can return Connections to the pool on exceptions
and so forth without making the caller be responsible for catching them.
If possible the function makes sure to return a connection to the pool.
"""
def __init__(self, conf, connection_pool, pooled=True, server_params=None):
"""Create a new connection, or get one from the pool."""
self.connection = None
self.conf = conf
self.connection_pool = connection_pool
if pooled:
self.connection = connection_pool.get()
else:
self.connection = connection_pool.connection_cls(
conf,
server_params=server_params)
self.pooled = pooled
def __enter__(self):
"""When with ConnectionContext() is used, return self."""
return self
def _done(self):
"""If the connection came from a pool, clean it up and put it back.
If it did not come from a pool, close it.
"""
if self.connection:
if self.pooled:
# Reset the connection so it's ready for the next caller
# to grab from the pool
self.connection.reset()
self.connection_pool.put(self.connection)
else:
try:
self.connection.close()
except Exception:
pass
self.connection = None
def __exit__(self, exc_type, exc_value, tb):
"""End of 'with' statement. We're done here."""
self._done()
def __del__(self):
"""Caller is done with this connection. Make sure we cleaned up."""
self._done()
def close(self):
"""Caller is done with this connection."""
self._done()
def create_consumer(self, topic, proxy, fanout=False):
self.connection.create_consumer(topic, proxy, fanout)
def create_worker(self, topic, proxy, pool_name):
self.connection.create_worker(topic, proxy, pool_name)
def join_consumer_pool(self, callback, pool_name, topic, exchange_name,
ack_on_error=True):
self.connection.join_consumer_pool(callback,
pool_name,
topic,
exchange_name,
ack_on_error)
def consume_in_thread(self):
self.connection.consume_in_thread()
def __getattr__(self, key):
"""Proxy all other calls to the Connection instance."""
if self.connection:
return getattr(self.connection, key)
else:
raise rpc_common.InvalidRPCConnectionReuse()
class ReplyProxy(ConnectionContext):
"""Connection class for RPC replies / callbacks."""
def __init__(self, conf, connection_pool):
self._call_waiters = {}
self._num_call_waiters = 0
self._num_call_waiters_wrn_threshhold = 10
self._reply_q = 'reply_' + uuid.uuid4().hex
super(ReplyProxy, self).__init__(conf, connection_pool, pooled=False)
self.declare_direct_consumer(self._reply_q, self._process_data)
self.consume_in_thread()
def _process_data(self, message_data):
msg_id = message_data.pop('_msg_id', None)
waiter = self._call_waiters.get(msg_id)
if not waiter:
LOG.warn(_('No calling threads waiting for msg_id : %(msg_id)s'
', message : %(data)s'), {'msg_id': msg_id,
'data': message_data})
LOG.warn(_('_call_waiters: %s') % str(self._call_waiters))
else:
waiter.put(message_data)
def add_call_waiter(self, waiter, msg_id):
self._num_call_waiters += 1
if self._num_call_waiters > self._num_call_waiters_wrn_threshhold:
LOG.warn(_('Number of call waiters is greater than warning '
'threshhold: %d. There could be a MulticallProxyWaiter '
'leak.') % self._num_call_waiters_wrn_threshhold)
self._num_call_waiters_wrn_threshhold *= 2
self._call_waiters[msg_id] = waiter
def del_call_waiter(self, msg_id):
self._num_call_waiters -= 1
del self._call_waiters[msg_id]
def get_reply_q(self):
return self._reply_q
def msg_reply(conf, msg_id, reply_q, connection_pool, reply=None,
failure=None, ending=False, log_failure=True):
"""Sends a reply or an error on the channel signified by msg_id.
Failure should be a sys.exc_info() tuple.
"""
with ConnectionContext(conf, connection_pool) as conn:
if failure:
failure = rpc_common.serialize_remote_exception(failure,
log_failure)
msg = {'result': reply, 'failure': failure}
if ending:
msg['ending'] = True
_add_unique_id(msg)
# If a reply_q exists, add the msg_id to the reply and pass the
# reply_q to direct_send() to use it as the response queue.
# Otherwise use the msg_id for backward compatibilty.
if reply_q:
msg['_msg_id'] = msg_id
conn.direct_send(reply_q, rpc_common.serialize_msg(msg))
else:
conn.direct_send(msg_id, rpc_common.serialize_msg(msg))
class RpcContext(rpc_common.CommonRpcContext):
"""Context that supports replying to a rpc.call."""
def __init__(self, **kwargs):
self.msg_id = kwargs.pop('msg_id', None)
self.reply_q = kwargs.pop('reply_q', None)
self.conf = kwargs.pop('conf')
super(RpcContext, self).__init__(**kwargs)
def deepcopy(self):
values = self.to_dict()
values['conf'] = self.conf
values['msg_id'] = self.msg_id
values['reply_q'] = self.reply_q
return self.__class__(**values)
def reply(self, reply=None, failure=None, ending=False,
connection_pool=None, log_failure=True):
if self.msg_id:
msg_reply(self.conf, self.msg_id, self.reply_q, connection_pool,
reply, failure, ending, log_failure)
if ending:
self.msg_id = None
def unpack_context(conf, msg):
"""Unpack context from msg."""
context_dict = {}
for key in list(msg.keys()):
# NOTE(vish): Some versions of python don't like unicode keys
# in kwargs.
key = str(key)
if key.startswith('_context_'):
value = msg.pop(key)
context_dict[key[9:]] = value
context_dict['msg_id'] = msg.pop('_msg_id', None)
context_dict['reply_q'] = msg.pop('_reply_q', None)
context_dict['conf'] = conf
ctx = RpcContext.from_dict(context_dict)
rpc_common._safe_log(LOG.debug, _('unpacked context: %s'), ctx.to_dict())
return ctx
def pack_context(msg, context):
"""Pack context into msg.
Values for message keys need to be less than 255 chars, so we pull
context out into a bunch of separate keys. If we want to support
more arguments in rabbit messages, we may want to do the same
for args at some point.
"""
context_d = dict([('_context_%s' % key, value)
for (key, value) in context.to_dict().iteritems()])
msg.update(context_d)
class _MsgIdCache(object):
"""This class checks any duplicate messages."""
# NOTE: This value is considered can be a configuration item, but
# it is not necessary to change its value in most cases,
# so let this value as static for now.
DUP_MSG_CHECK_SIZE = 16
def __init__(self, **kwargs):
self.prev_msgids = collections.deque([],
maxlen=self.DUP_MSG_CHECK_SIZE)
def check_duplicate_message(self, message_data):
"""AMQP consumers may read same message twice when exceptions occur
before ack is returned. This method prevents doing it.
"""
if UNIQUE_ID in message_data:
msg_id = message_data[UNIQUE_ID]
if msg_id not in self.prev_msgids:
self.prev_msgids.append(msg_id)
else:
raise rpc_common.DuplicateMessageError(msg_id=msg_id)
def _add_unique_id(msg):
"""Add unique_id for checking duplicate messages."""
unique_id = uuid.uuid4().hex
msg.update({UNIQUE_ID: unique_id})
LOG.debug(_('UNIQUE_ID is %s.') % (unique_id))
class _ThreadPoolWithWait(object):
"""Base class for a delayed invocation manager.
Used by the Connection class to start up green threads
to handle incoming messages.
"""
def __init__(self, conf, connection_pool):
self.pool = greenpool.GreenPool(conf.rpc_thread_pool_size)
self.connection_pool = connection_pool
self.conf = conf
def wait(self):
"""Wait for all callback threads to exit."""
self.pool.waitall()
class CallbackWrapper(_ThreadPoolWithWait):
"""Wraps a straight callback.
Allows it to be invoked in a green thread.
"""
def __init__(self, conf, callback, connection_pool):
"""Initiates CallbackWrapper object.
:param conf: cfg.CONF instance
:param callback: a callable (probably a function)
:param connection_pool: connection pool as returned by
get_connection_pool()
"""
super(CallbackWrapper, self).__init__(
conf=conf,
connection_pool=connection_pool,
)
self.callback = callback
def __call__(self, message_data):
self.pool.spawn_n(self.callback, message_data)
class ProxyCallback(_ThreadPoolWithWait):
"""Calls methods on a proxy object based on method and args."""
def __init__(self, conf, proxy, connection_pool):
super(ProxyCallback, self).__init__(
conf=conf,
connection_pool=connection_pool,
)
self.proxy = proxy
self.msg_id_cache = _MsgIdCache()
def __call__(self, message_data):
"""Consumer callback to call a method on a proxy object.
Parses the message for validity and fires off a thread to call the
proxy object method.
Message data should be a dictionary with two keys:
method: string representing the method to call
args: dictionary of arg: value
Example: {'method': 'echo', 'args': {'value': 42}}
"""
# It is important to clear the context here, because at this point
# the previous context is stored in local.store.context
if hasattr(local.store, 'context'):
del local.store.context
rpc_common._safe_log(LOG.debug, _('received %s'), message_data)
self.msg_id_cache.check_duplicate_message(message_data)
ctxt = unpack_context(self.conf, message_data)
method = message_data.get('method')
args = message_data.get('args', {})
version = message_data.get('version')
namespace = message_data.get('namespace')
if not method:
LOG.warn(_('no method for message: %s') % message_data)
ctxt.reply(_('No method for message: %s') % message_data,
connection_pool=self.connection_pool)
return
self.pool.spawn_n(self._process_data, ctxt, version, method,
namespace, args)
def _process_data(self, ctxt, version, method, namespace, args):
"""Process a message in a new thread.
If the proxy object we have has a dispatch method
(see rpc.dispatcher.RpcDispatcher), pass it the version,
method, and args and let it dispatch as appropriate. If not, use
the old behavior of magically calling the specified method on the
proxy we have here.
"""
ctxt.update_store()
try:
rval = self.proxy.dispatch(ctxt, version, method, namespace,
**args)
# Check if the result was a generator
if inspect.isgenerator(rval):
for x in rval:
ctxt.reply(x, None, connection_pool=self.connection_pool)
else:
ctxt.reply(rval, None, connection_pool=self.connection_pool)
# This final None tells multicall that it is done.
ctxt.reply(ending=True, connection_pool=self.connection_pool)
except rpc_common.ClientException as e:
LOG.debug(_('Expected exception during message handling (%s)') %
e._exc_info[1])
ctxt.reply(None, e._exc_info,
connection_pool=self.connection_pool,
log_failure=False)
except Exception:
# sys.exc_info() is deleted by LOG.exception().
exc_info = sys.exc_info()
LOG.error(_('Exception during message handling'),
exc_info=exc_info)
ctxt.reply(None, exc_info, connection_pool=self.connection_pool)
class MulticallProxyWaiter(object):
def __init__(self, conf, msg_id, timeout, connection_pool):
self._msg_id = msg_id
self._timeout = timeout or conf.rpc_response_timeout
self._reply_proxy = connection_pool.reply_proxy
self._done = False
self._got_ending = False
self._conf = conf
self._dataqueue = queue.LightQueue()
# Add this caller to the reply proxy's call_waiters
self._reply_proxy.add_call_waiter(self, self._msg_id)
self.msg_id_cache = _MsgIdCache()
def put(self, data):
self._dataqueue.put(data)
def done(self):
if self._done:
return
self._done = True
# Remove this caller from reply proxy's call_waiters
self._reply_proxy.del_call_waiter(self._msg_id)
def _process_data(self, data):
result = None
self.msg_id_cache.check_duplicate_message(data)
if data['failure']:
failure = data['failure']
result = rpc_common.deserialize_remote_exception(self._conf,
failure)
elif data.get('ending', False):
self._got_ending = True
else:
result = data['result']
return result
def __iter__(self):
"""Return a result until we get a reply with an 'ending' flag."""
if self._done:
raise StopIteration
while True:
try:
data = self._dataqueue.get(timeout=self._timeout)
result = self._process_data(data)
except queue.Empty:
self.done()
raise rpc_common.Timeout()
except Exception:
with excutils.save_and_reraise_exception():
self.done()
if self._got_ending:
self.done()
raise StopIteration
if isinstance(result, Exception):
self.done()
raise result
yield result
def create_connection(conf, new, connection_pool):
"""Create a connection."""
return ConnectionContext(conf, connection_pool, pooled=not new)
_reply_proxy_create_sem = semaphore.Semaphore()
def multicall(conf, context, topic, msg, timeout, connection_pool):
"""Make a call that returns multiple times."""
LOG.debug(_('Making synchronous call on %s ...'), topic)
msg_id = uuid.uuid4().hex
msg.update({'_msg_id': msg_id})
LOG.debug(_('MSG_ID is %s') % (msg_id))
_add_unique_id(msg)
pack_context(msg, context)
with _reply_proxy_create_sem:
if not connection_pool.reply_proxy:
connection_pool.reply_proxy = ReplyProxy(conf, connection_pool)
msg.update({'_reply_q': connection_pool.reply_proxy.get_reply_q()})
wait_msg = MulticallProxyWaiter(conf, msg_id, timeout, connection_pool)
with ConnectionContext(conf, connection_pool) as conn:
conn.topic_send(topic, rpc_common.serialize_msg(msg), timeout)
return wait_msg
def call(conf, context, topic, msg, timeout, connection_pool):
"""Sends a message on a topic and wait for a response."""
rv = multicall(conf, context, topic, msg, timeout, connection_pool)
# NOTE(vish): return the last result from the multicall
rv = list(rv)
if not rv:
return
return rv[-1]
def cast(conf, context, topic, msg, connection_pool):
"""Sends a message on a topic without waiting for a response."""
LOG.debug(_('Making asynchronous cast on %s...'), topic)
_add_unique_id(msg)
pack_context(msg, context)
with ConnectionContext(conf, connection_pool) as conn:
conn.topic_send(topic, rpc_common.serialize_msg(msg))
def fanout_cast(conf, context, topic, msg, connection_pool):
"""Sends a message on a fanout exchange without waiting for a response."""
LOG.debug(_('Making asynchronous fanout cast...'))
_add_unique_id(msg)
pack_context(msg, context)
with ConnectionContext(conf, connection_pool) as conn:
conn.fanout_send(topic, rpc_common.serialize_msg(msg))
def cast_to_server(conf, context, server_params, topic, msg, connection_pool):
"""Sends a message on a topic to a specific server."""
_add_unique_id(msg)
pack_context(msg, context)
with ConnectionContext(conf, connection_pool, pooled=False,
server_params=server_params) as conn:
conn.topic_send(topic, rpc_common.serialize_msg(msg))
def fanout_cast_to_server(conf, context, server_params, topic, msg,
connection_pool):
"""Sends a message on a fanout exchange to a specific server."""
_add_unique_id(msg)
pack_context(msg, context)
with ConnectionContext(conf, connection_pool, pooled=False,
server_params=server_params) as conn:
conn.fanout_send(topic, rpc_common.serialize_msg(msg))
def notify(conf, context, topic, msg, connection_pool, envelope):
"""Sends a notification event on a topic."""
LOG.debug(_('Sending %(event_type)s on %(topic)s'),
dict(event_type=msg.get('event_type'),
topic=topic))
_add_unique_id(msg)
pack_context(msg, context)
with ConnectionContext(conf, connection_pool) as conn:
if envelope:
msg = rpc_common.serialize_msg(msg)
conn.notify_send(topic, msg)
def cleanup(connection_pool):
if connection_pool:
connection_pool.empty()
def get_control_exchange(conf):
return conf.control_exchange

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oslo/messaging/_drivers/common.py Normal file
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
# Copyright 2011 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 copy
import sys
import traceback
from oslo.config import cfg
import six
from openstack.common.gettextutils import _ # noqa
from openstack.common import importutils
from openstack.common import jsonutils
from openstack.common import local
from openstack.common import log as logging
CONF = cfg.CONF
LOG = logging.getLogger(__name__)
'''RPC Envelope Version.
This version number applies to the top level structure of messages sent out.
It does *not* apply to the message payload, which must be versioned
independently. For example, when using rpc APIs, a version number is applied
for changes to the API being exposed over rpc. This version number is handled
in the rpc proxy and dispatcher modules.
This version number applies to the message envelope that is used in the
serialization done inside the rpc layer. See serialize_msg() and
deserialize_msg().
The current message format (version 2.0) is very simple. It is:
{
'oslo.version': <RPC Envelope Version as a String>,
'oslo.message': <Application Message Payload, JSON encoded>
}
Message format version '1.0' is just considered to be the messages we sent
without a message envelope.
So, the current message envelope just includes the envelope version. It may
eventually contain additional information, such as a signature for the message
payload.
We will JSON encode the application message payload. The message envelope,
which includes the JSON encoded application message body, will be passed down
to the messaging libraries as a dict.
'''
_RPC_ENVELOPE_VERSION = '2.0'
_VERSION_KEY = 'oslo.version'
_MESSAGE_KEY = 'oslo.message'
_REMOTE_POSTFIX = '_Remote'
class RPCException(Exception):
msg_fmt = _("An unknown RPC related exception occurred.")
def __init__(self, message=None, **kwargs):
self.kwargs = kwargs
if not message:
try:
message = self.msg_fmt % kwargs
except Exception:
# kwargs doesn't match a variable in the message
# log the issue and the kwargs
LOG.exception(_('Exception in string format operation'))
for name, value in kwargs.iteritems():
LOG.error("%s: %s" % (name, value))
# at least get the core message out if something happened
message = self.msg_fmt
super(RPCException, self).__init__(message)
class RemoteError(RPCException):
"""Signifies that a remote class has raised an exception.
Contains a string representation of the type of the original exception,
the value of the original exception, and the traceback. These are
sent to the parent as a joined string so printing the exception
contains all of the relevant info.
"""
msg_fmt = _("Remote error: %(exc_type)s %(value)s\n%(traceback)s.")
def __init__(self, exc_type=None, value=None, traceback=None):
self.exc_type = exc_type
self.value = value
self.traceback = traceback
super(RemoteError, self).__init__(exc_type=exc_type,
value=value,
traceback=traceback)
class Timeout(RPCException):
"""Signifies that a timeout has occurred.
This exception is raised if the rpc_response_timeout is reached while
waiting for a response from the remote side.
"""
msg_fmt = _('Timeout while waiting on RPC response - '
'topic: "%(topic)s", RPC method: "%(method)s" '
'info: "%(info)s"')
def __init__(self, info=None, topic=None, method=None):
"""Initiates Timeout object.
:param info: Extra info to convey to the user
:param topic: The topic that the rpc call was sent to
:param rpc_method_name: The name of the rpc method being
called
"""
self.info = info
self.topic = topic
self.method = method
super(Timeout, self).__init__(
None,
info=info or _('<unknown>'),
topic=topic or _('<unknown>'),
method=method or _('<unknown>'))
class DuplicateMessageError(RPCException):
msg_fmt = _("Found duplicate message(%(msg_id)s). Skipping it.")
class InvalidRPCConnectionReuse(RPCException):
msg_fmt = _("Invalid reuse of an RPC connection.")
class UnsupportedRpcVersion(RPCException):
msg_fmt = _("Specified RPC version, %(version)s, not supported by "
"this endpoint.")
class UnsupportedRpcEnvelopeVersion(RPCException):
msg_fmt = _("Specified RPC envelope version, %(version)s, "
"not supported by this endpoint.")
class RpcVersionCapError(RPCException):
msg_fmt = _("Specified RPC version cap, %(version_cap)s, is too low")
class Connection(object):
"""A connection, returned by rpc.create_connection().
This class represents a connection to the message bus used for rpc.
An instance of this class should never be created by users of the rpc API.
Use rpc.create_connection() instead.
"""
def close(self):
"""Close the connection.
This method must be called when the connection will no longer be used.
It will ensure that any resources associated with the connection, such
as a network connection, and cleaned up.
"""
raise NotImplementedError()
def create_consumer(self, topic, proxy, fanout=False):
"""Create a consumer on this connection.
A consumer is associated with a message queue on the backend message
bus. The consumer will read messages from the queue, unpack them, and
dispatch them to the proxy object. The contents of the message pulled
off of the queue will determine which method gets called on the proxy
object.
:param topic: This is a name associated with what to consume from.
Multiple instances of a service may consume from the same
topic. For example, all instances of nova-compute consume
from a queue called "compute". In that case, the
messages will get distributed amongst the consumers in a
round-robin fashion if fanout=False. If fanout=True,
every consumer associated with this topic will get a
copy of every message.
:param proxy: The object that will handle all incoming messages.
:param fanout: Whether or not this is a fanout topic. See the
documentation for the topic parameter for some
additional comments on this.
"""
raise NotImplementedError()
def create_worker(self, topic, proxy, pool_name):
"""Create a worker on this connection.
A worker is like a regular consumer of messages directed to a
topic, except that it is part of a set of such consumers (the
"pool") which may run in parallel. Every pool of workers will
receive a given message, but only one worker in the pool will
be asked to process it. Load is distributed across the members
of the pool in round-robin fashion.
:param topic: This is a name associated with what to consume from.
Multiple instances of a service may consume from the same
topic.
:param proxy: The object that will handle all incoming messages.
:param pool_name: String containing the name of the pool of workers
"""
raise NotImplementedError()
def join_consumer_pool(self, callback, pool_name, topic, exchange_name):
"""Register as a member of a group of consumers.
Uses given topic from the specified exchange.
Exactly one member of a given pool will receive each message.
A message will be delivered to multiple pools, if more than
one is created.
:param callback: Callable to be invoked for each message.
:type callback: callable accepting one argument
:param pool_name: The name of the consumer pool.
:type pool_name: str
:param topic: The routing topic for desired messages.
:type topic: str
:param exchange_name: The name of the message exchange where
the client should attach. Defaults to
the configured exchange.
:type exchange_name: str
"""
raise NotImplementedError()
def consume_in_thread(self):
"""Spawn a thread to handle incoming messages.
Spawn a thread that will be responsible for handling all incoming
messages for consumers that were set up on this connection.
Message dispatching inside of this is expected to be implemented in a
non-blocking manner. An example implementation would be having this
thread pull messages in for all of the consumers, but utilize a thread
pool for dispatching the messages to the proxy objects.
"""
raise NotImplementedError()
def _safe_log(log_func, msg, msg_data):
"""Sanitizes the msg_data field before logging."""
SANITIZE = ['_context_auth_token', 'auth_token', 'new_pass']
def _fix_passwords(d):
"""Sanitizes the password fields in the dictionary."""
for k in d.iterkeys():
if k.lower().find('password') != -1:
d[k] = '<SANITIZED>'
elif k.lower() in SANITIZE:
d[k] = '<SANITIZED>'
elif isinstance(d[k], dict):
_fix_passwords(d[k])
return d
return log_func(msg, _fix_passwords(copy.deepcopy(msg_data)))
def serialize_remote_exception(failure_info, log_failure=True):
"""Prepares exception data to be sent over rpc.
Failure_info should be a sys.exc_info() tuple.
"""
tb = traceback.format_exception(*failure_info)
failure = failure_info[1]
if log_failure:
LOG.error(_("Returning exception %s to caller"),
six.text_type(failure))
LOG.error(tb)
kwargs = {}
if hasattr(failure, 'kwargs'):
kwargs = failure.kwargs
# NOTE(matiu): With cells, it's possible to re-raise remote, remote
# exceptions. Lets turn it back into the original exception type.
cls_name = str(failure.__class__.__name__)
mod_name = str(failure.__class__.__module__)
if (cls_name.endswith(_REMOTE_POSTFIX) and
mod_name.endswith(_REMOTE_POSTFIX)):
cls_name = cls_name[:-len(_REMOTE_POSTFIX)]
mod_name = mod_name[:-len(_REMOTE_POSTFIX)]
data = {
'class': cls_name,
'module': mod_name,
'message': six.text_type(failure),
'tb': tb,
'args': failure.args,
'kwargs': kwargs
}
json_data = jsonutils.dumps(data)
return json_data
def deserialize_remote_exception(conf, data):
failure = jsonutils.loads(str(data))
trace = failure.get('tb', [])
message = failure.get('message', "") + "\n" + "\n".join(trace)
name = failure.get('class')
module = failure.get('module')
# NOTE(ameade): We DO NOT want to allow just any module to be imported, in
# order to prevent arbitrary code execution.
if module not in conf.allowed_rpc_exception_modules:
return RemoteError(name, failure.get('message'), trace)
try:
mod = importutils.import_module(module)
klass = getattr(mod, name)
if not issubclass(klass, Exception):
raise TypeError("Can only deserialize Exceptions")
failure = klass(*failure.get('args', []), **failure.get('kwargs', {}))
except (AttributeError, TypeError, ImportError):
return RemoteError(name, failure.get('message'), trace)
ex_type = type(failure)
str_override = lambda self: message
new_ex_type = type(ex_type.__name__ + _REMOTE_POSTFIX, (ex_type,),
{'__str__': str_override, '__unicode__': str_override})
new_ex_type.__module__ = '%s%s' % (module, _REMOTE_POSTFIX)
try:
# NOTE(ameade): Dynamically create a new exception type and swap it in
# as the new type for the exception. This only works on user defined
# Exceptions and not core python exceptions. This is important because
# we cannot necessarily change an exception message so we must override
# the __str__ method.
failure.__class__ = new_ex_type
except TypeError:
# NOTE(ameade): If a core exception then just add the traceback to the
# first exception argument.
failure.args = (message,) + failure.args[1:]
return failure
class CommonRpcContext(object):
def __init__(self, **kwargs):
self.values = kwargs
def __getattr__(self, key):
try:
return self.values[key]
except KeyError:
raise AttributeError(key)
def to_dict(self):
return copy.deepcopy(self.values)
@classmethod
def from_dict(cls, values):
return cls(**values)
def deepcopy(self):
return self.from_dict(self.to_dict())
def update_store(self):
local.store.context = self
def elevated(self, read_deleted=None, overwrite=False):
"""Return a version of this context with admin flag set."""
# TODO(russellb) This method is a bit of a nova-ism. It makes
# some assumptions about the data in the request context sent
# across rpc, while the rest of this class does not. We could get
# rid of this if we changed the nova code that uses this to
# convert the RpcContext back to its native RequestContext doing
# something like nova.context.RequestContext.from_dict(ctxt.to_dict())
context = self.deepcopy()
context.values['is_admin'] = True
context.values.setdefault('roles', [])
if 'admin' not in context.values['roles']:
context.values['roles'].append('admin')
if read_deleted is not None:
context.values['read_deleted'] = read_deleted
return context
class ClientException(Exception):
"""Encapsulates actual exception expected to be hit by a RPC proxy object.
Merely instantiating it records the current exception information, which
will be passed back to the RPC client without exceptional logging.
"""
def __init__(self):
self._exc_info = sys.exc_info()
def catch_client_exception(exceptions, func, *args, **kwargs):
try:
return func(*args, **kwargs)
except Exception as e:
if type(e) in exceptions:
raise ClientException()
else:
raise
def client_exceptions(*exceptions):
"""Decorator for manager methods that raise expected exceptions.
Marking a Manager method with this decorator allows the declaration
of expected exceptions that the RPC layer should not consider fatal,
and not log as if they were generated in a real error scenario. Note
that this will cause listed exceptions to be wrapped in a
ClientException, which is used internally by the RPC layer.
"""
def outer(func):
def inner(*args, **kwargs):
return catch_client_exception(exceptions, func, *args, **kwargs)
return inner
return outer
def version_is_compatible(imp_version, version):
"""Determine whether versions are compatible.
:param imp_version: The version implemented
:param version: The version requested by an incoming message.
"""
version_parts = version.split('.')
imp_version_parts = imp_version.split('.')
if int(version_parts[0]) != int(imp_version_parts[0]): # Major
return False
if int(version_parts[1]) > int(imp_version_parts[1]): # Minor
return False
return True
def serialize_msg(raw_msg):
# NOTE(russellb) See the docstring for _RPC_ENVELOPE_VERSION for more
# information about this format.
msg = {_VERSION_KEY: _RPC_ENVELOPE_VERSION,
_MESSAGE_KEY: jsonutils.dumps(raw_msg)}
return msg
def deserialize_msg(msg):
# NOTE(russellb): Hang on to your hats, this road is about to
# get a little bumpy.
#
# Robustness Principle:
# "Be strict in what you send, liberal in what you accept."
#
# At this point we have to do a bit of guessing about what it
# is we just received. Here is the set of possibilities:
#
# 1) We received a dict. This could be 2 things:
#
# a) Inspect it to see if it looks like a standard message envelope.
# If so, great!
#
# b) If it doesn't look like a standard message envelope, it could either
# be a notification, or a message from before we added a message
# envelope (referred to as version 1.0).
# Just return the message as-is.
#
# 2) It's any other non-dict type. Just return it and hope for the best.
# This case covers return values from rpc.call() from before message
# envelopes were used. (messages to call a method were always a dict)
if not isinstance(msg, dict):
# See #2 above.
return msg
base_envelope_keys = (_VERSION_KEY, _MESSAGE_KEY)
if not all(map(lambda key: key in msg, base_envelope_keys)):
# See #1.b above.
return msg
# At this point we think we have the message envelope
# format we were expecting. (#1.a above)
if not version_is_compatible(_RPC_ENVELOPE_VERSION, msg[_VERSION_KEY]):
raise UnsupportedRpcEnvelopeVersion(version=msg[_VERSION_KEY])
raw_msg = jsonutils.loads(msg[_MESSAGE_KEY])
return raw_msg

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# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 OpenStack Foundation
# Copyright 2011 - 2012, 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 functools
import itertools
import time
import uuid
import eventlet
import greenlet
from oslo.config import cfg
from openstack.common import excutils
from openstack.common.gettextutils import _ # noqa
from openstack.common import importutils
from openstack.common import jsonutils
from openstack.common import log as logging
from openstack.common.rpc import amqp as rpc_amqp
from openstack.common.rpc import common as rpc_common
qpid_codec = importutils.try_import("qpid.codec010")
qpid_messaging = importutils.try_import("qpid.messaging")
qpid_exceptions = importutils.try_import("qpid.messaging.exceptions")
LOG = logging.getLogger(__name__)
qpid_opts = [
cfg.StrOpt('qpid_hostname',
default='localhost',
help='Qpid broker hostname'),
cfg.IntOpt('qpid_port',
default=5672,
help='Qpid broker port'),
cfg.ListOpt('qpid_hosts',
default=['$qpid_hostname:$qpid_port'],
help='Qpid HA cluster host:port pairs'),
cfg.StrOpt('qpid_username',
default='',
help='Username for qpid connection'),
cfg.StrOpt('qpid_password',
default='',
help='Password for qpid connection',
secret=True),
cfg.StrOpt('qpid_sasl_mechanisms',
default='',
help='Space separated list of SASL mechanisms to use for auth'),
cfg.IntOpt('qpid_heartbeat',
default=60,
help='Seconds between connection keepalive heartbeats'),
cfg.StrOpt('qpid_protocol',
default='tcp',
help="Transport to use, either 'tcp' or 'ssl'"),
cfg.BoolOpt('qpid_tcp_nodelay',
default=True,
help='Disable Nagle algorithm'),
]
cfg.CONF.register_opts(qpid_opts)
JSON_CONTENT_TYPE = 'application/json; charset=utf8'
class ConsumerBase(object):
"""Consumer base class."""
def __init__(self, session, callback, node_name, node_opts,
link_name, link_opts):
"""Declare a queue on an amqp session.
'session' is the amqp session to use
'callback' is the callback to call when messages are received
'node_name' is the first part of the Qpid address string, before ';'
'node_opts' will be applied to the "x-declare" section of "node"
in the address string.
'link_name' goes into the "name" field of the "link" in the address
string
'link_opts' will be applied to the "x-declare" section of "link"
in the address string.
"""
self.callback = callback
self.receiver = None
self.session = None
addr_opts = {
"create": "always",
"node": {
"type": "topic",
"x-declare": {
"durable": True,
"auto-delete": True,
},
},
"link": {
"name": link_name,
"durable": True,
"x-declare": {
"durable": False,
"auto-delete": True,
"exclusive": False,
},
},
}
addr_opts["node"]["x-declare"].update(node_opts)
addr_opts["link"]["x-declare"].update(link_opts)
self.address = "%s ; %s" % (node_name, jsonutils.dumps(addr_opts))
self.connect(session)
def connect(self, session):
"""Declare the reciever on connect."""
self._declare_receiver(session)
def reconnect(self, session):
"""Re-declare the receiver after a qpid reconnect."""
self._declare_receiver(session)
def _declare_receiver(self, session):
self.session = session
self.receiver = session.receiver(self.address)
self.receiver.capacity = 1
def _unpack_json_msg(self, msg):
"""Load the JSON data in msg if msg.content_type indicates that it
is necessary. Put the loaded data back into msg.content and
update msg.content_type appropriately.
A Qpid Message containing a dict will have a content_type of
'amqp/map', whereas one containing a string that needs to be converted
back from JSON will have a content_type of JSON_CONTENT_TYPE.
:param msg: a Qpid Message object
:returns: None
"""
if msg.content_type == JSON_CONTENT_TYPE:
msg.content = jsonutils.loads(msg.content)
msg.content_type = 'amqp/map'
def consume(self):
"""Fetch the message and pass it to the callback object."""
message = self.receiver.fetch()
try:
self._unpack_json_msg(message)
msg = rpc_common.deserialize_msg(message.content)
self.callback(msg)
except Exception:
LOG.exception(_("Failed to process message... skipping it."))
finally:
# TODO(sandy): Need support for optional ack_on_error.
self.session.acknowledge(message)
def get_receiver(self):
return self.receiver
def get_node_name(self):
return self.address.split(';')[0]
class DirectConsumer(ConsumerBase):
"""Queue/consumer class for 'direct'."""
def __init__(self, conf, session, msg_id, callback):
"""Init a 'direct' queue.
'session' is the amqp session to use
'msg_id' is the msg_id to listen on
'callback' is the callback to call when messages are received
"""
super(DirectConsumer, self).__init__(
session, callback,
"%s/%s" % (msg_id, msg_id),
{"type": "direct"},
msg_id,
{
"auto-delete": conf.amqp_auto_delete,
"exclusive": True,
"durable": conf.amqp_durable_queues,
})
class TopicConsumer(ConsumerBase):
"""Consumer class for 'topic'."""
def __init__(self, conf, session, topic, callback, name=None,
exchange_name=None):
"""Init a 'topic' queue.
:param session: the amqp session to use
:param topic: is the topic to listen on
:paramtype topic: str
:param callback: the callback to call when messages are received
:param name: optional queue name, defaults to topic
"""
exchange_name = exchange_name or rpc_amqp.get_control_exchange(conf)
super(TopicConsumer, self).__init__(
session, callback,
"%s/%s" % (exchange_name, topic),
{}, name or topic,
{
"auto-delete": conf.amqp_auto_delete,
"durable": conf.amqp_durable_queues,
})
class FanoutConsumer(ConsumerBase):
"""Consumer class for 'fanout'."""
def __init__(self, conf, session, topic, callback):
"""Init a 'fanout' queue.
'session' is the amqp session to use
'topic' is the topic to listen on
'callback' is the callback to call when messages are received
"""
self.conf = conf
super(FanoutConsumer, self).__init__(
session, callback,
"%s_fanout" % topic,
{"durable": False, "type": "fanout"},
"%s_fanout_%s" % (topic, uuid.uuid4().hex),
{"exclusive": True})
def reconnect(self, session):
topic = self.get_node_name().rpartition('_fanout')[0]
params = {
'session': session,
'topic': topic,
'callback': self.callback,
}
self.__init__(conf=self.conf, **params)
super(FanoutConsumer, self).reconnect(session)
class Publisher(object):
"""Base Publisher class."""
def __init__(self, session, node_name, node_opts=None):
"""Init the Publisher class with the exchange_name, routing_key,
and other options
"""
self.sender = None
self.session = session
addr_opts = {
"create": "always",
"node": {
"type": "topic",
"x-declare": {
"durable": False,
# auto-delete isn't implemented for exchanges in qpid,
# but put in here anyway
"auto-delete": True,
},
},
}
if node_opts:
addr_opts["node"]["x-declare"].update(node_opts)
self.address = "%s ; %s" % (node_name, jsonutils.dumps(addr_opts))
self.reconnect(session)
def reconnect(self, session):
"""Re-establish the Sender after a reconnection."""
self.sender = session.sender(self.address)
def _pack_json_msg(self, msg):
"""Qpid cannot serialize dicts containing strings longer than 65535
characters. This function dumps the message content to a JSON
string, which Qpid is able to handle.
:param msg: May be either a Qpid Message object or a bare dict.
:returns: A Qpid Message with its content field JSON encoded.
"""
try:
msg.content = jsonutils.dumps(msg.content)
except AttributeError:
# Need to have a Qpid message so we can set the content_type.
msg = qpid_messaging.Message(jsonutils.dumps(msg))
msg.content_type = JSON_CONTENT_TYPE
return msg
def send(self, msg):
"""Send a message."""
try:
# Check if Qpid can encode the message
check_msg = msg
if not hasattr(check_msg, 'content_type'):
check_msg = qpid_messaging.Message(msg)
content_type = check_msg.content_type
enc, dec = qpid_messaging.message.get_codec(content_type)
enc(check_msg.content)
except qpid_codec.CodecException:
# This means the message couldn't be serialized as a dict.
msg = self._pack_json_msg(msg)
self.sender.send(msg)
class DirectPublisher(Publisher):
"""Publisher class for 'direct'."""
def __init__(self, conf, session, msg_id):
"""Init a 'direct' publisher."""
super(DirectPublisher, self).__init__(session, msg_id,
{"type": "Direct"})
class TopicPublisher(Publisher):
"""Publisher class for 'topic'."""
def __init__(self, conf, session, topic):
"""init a 'topic' publisher.
"""
exchange_name = rpc_amqp.get_control_exchange(conf)
super(TopicPublisher, self).__init__(session,
"%s/%s" % (exchange_name, topic))
class FanoutPublisher(Publisher):
"""Publisher class for 'fanout'."""
def __init__(self, conf, session, topic):
"""init a 'fanout' publisher.
"""
super(FanoutPublisher, self).__init__(
session,
"%s_fanout" % topic, {"type": "fanout"})
class NotifyPublisher(Publisher):
"""Publisher class for notifications."""
def __init__(self, conf, session, topic):
"""init a 'topic' publisher.
"""
exchange_name = rpc_amqp.get_control_exchange(conf)
super(NotifyPublisher, self).__init__(session,
"%s/%s" % (exchange_name, topic),
{"durable": True})
class Connection(object):
"""Connection object."""
pool = None
def __init__(self, conf, server_params=None):
if not qpid_messaging:
raise ImportError("Failed to import qpid.messaging")
self.session = None
self.consumers = {}
self.consumer_thread = None
self.proxy_callbacks = []
self.conf = conf
if server_params and 'hostname' in server_params:
# NOTE(russellb) This enables support for cast_to_server.
server_params['qpid_hosts'] = [
'%s:%d' % (server_params['hostname'],
server_params.get('port', 5672))
]
params = {
'qpid_hosts': self.conf.qpid_hosts,
'username': self.conf.qpid_username,
'password': self.conf.qpid_password,
}
params.update(server_params or {})
self.brokers = params['qpid_hosts']
self.username = params['username']
self.password = params['password']
self.connection_create(self.brokers[0])
self.reconnect()
def connection_create(self, broker):
# Create the connection - this does not open the connection
self.connection = qpid_messaging.Connection(broker)
# Check if flags are set and if so set them for the connection
# before we call open
self.connection.username = self.username
self.connection.password = self.password
self.connection.sasl_mechanisms = self.conf.qpid_sasl_mechanisms
# Reconnection is done by self.reconnect()
self.connection.reconnect = False
self.connection.heartbeat = self.conf.qpid_heartbeat
self.connection.transport = self.conf.qpid_protocol
self.connection.tcp_nodelay = self.conf.qpid_tcp_nodelay
def _register_consumer(self, consumer):
self.consumers[str(consumer.get_receiver())] = consumer
def _lookup_consumer(self, receiver):
return self.consumers[str(receiver)]
def reconnect(self):
"""Handles reconnecting and re-establishing sessions and queues."""
attempt = 0
delay = 1
while True:
# Close the session if necessary
if self.connection.opened():
try:
self.connection.close()
except qpid_exceptions.ConnectionError:
pass
broker = self.brokers[attempt % len(self.brokers)]
attempt += 1
try:
self.connection_create(broker)
self.connection.open()
except qpid_exceptions.ConnectionError as e:
msg_dict = dict(e=e, delay=delay)
msg = _("Unable to connect to AMQP server: %(e)s. "
"Sleeping %(delay)s seconds") % msg_dict
LOG.error(msg)
time.sleep(delay)
delay = min(2 * delay, 60)
else:
LOG.info(_('Connected to AMQP server on %s'), broker)
break
self.session = self.connection.session()
if self.consumers:
consumers = self.consumers
self.consumers = {}
for consumer in consumers.itervalues():
consumer.reconnect(self.session)
self._register_consumer(consumer)
LOG.debug(_("Re-established AMQP queues"))
def ensure(self, error_callback, method, *args, **kwargs):
while True:
try:
return method(*args, **kwargs)
except (qpid_exceptions.Empty,
qpid_exceptions.ConnectionError) as e:
if error_callback:
error_callback(e)
self.reconnect()
def close(self):
"""Close/release this connection."""
self.cancel_consumer_thread()
self.wait_on_proxy_callbacks()
try:
self.connection.close()
except Exception:
# NOTE(dripton) Logging exceptions that happen during cleanup just
# causes confusion; there's really nothing useful we can do with
# them.
pass
self.connection = None
def reset(self):
"""Reset a connection so it can be used again."""
self.cancel_consumer_thread()
self.wait_on_proxy_callbacks()
self.session.close()
self.session = self.connection.session()
self.consumers = {}
def declare_consumer(self, consumer_cls, topic, callback):
"""Create a Consumer using the class that was passed in and
add it to our list of consumers
"""
def _connect_error(exc):
log_info = {'topic': topic, 'err_str': str(exc)}
LOG.error(_("Failed to declare consumer for topic '%(topic)s': "
"%(err_str)s") % log_info)
def _declare_consumer():
consumer = consumer_cls(self.conf, self.session, topic, callback)
self._register_consumer(consumer)
return consumer
return self.ensure(_connect_error, _declare_consumer)
def iterconsume(self, limit=None, timeout=None):
"""Return an iterator that will consume from all queues/consumers."""
def _error_callback(exc):
if isinstance(exc, qpid_exceptions.Empty):
LOG.debug(_('Timed out waiting for RPC response: %s') %
str(exc))
raise rpc_common.Timeout()
else:
LOG.exception(_('Failed to consume message from queue: %s') %
str(exc))
def _consume():
nxt_receiver = self.session.next_receiver(timeout=timeout)
try:
self._lookup_consumer(nxt_receiver).consume()
except Exception:
LOG.exception(_("Error processing message. Skipping it."))
for iteration in itertools.count(0):
if limit and iteration >= limit:
raise StopIteration
yield self.ensure(_error_callback, _consume)
def cancel_consumer_thread(self):
"""Cancel a consumer thread."""
if self.consumer_thread is not None:
self.consumer_thread.kill()
try:
self.consumer_thread.wait()
except greenlet.GreenletExit:
pass
self.consumer_thread = None
def wait_on_proxy_callbacks(self):
"""Wait for all proxy callback threads to exit."""
for proxy_cb in self.proxy_callbacks:
proxy_cb.wait()
def publisher_send(self, cls, topic, msg):
"""Send to a publisher based on the publisher class."""
def _connect_error(exc):
log_info = {'topic': topic, 'err_str': str(exc)}
LOG.exception(_("Failed to publish message to topic "
"'%(topic)s': %(err_str)s") % log_info)
def _publisher_send():
publisher = cls(self.conf, self.session, topic)
publisher.send(msg)
return self.ensure(_connect_error, _publisher_send)
def declare_direct_consumer(self, topic, callback):
"""Create a 'direct' queue.
In nova's use, this is generally a msg_id queue used for
responses for call/multicall
"""
self.declare_consumer(DirectConsumer, topic, callback)
def declare_topic_consumer(self, topic, callback=None, queue_name=None,
exchange_name=None):
"""Create a 'topic' consumer."""
self.declare_consumer(functools.partial(TopicConsumer,
name=queue_name,
exchange_name=exchange_name,
),
topic, callback)
def declare_fanout_consumer(self, topic, callback):
"""Create a 'fanout' consumer."""
self.declare_consumer(FanoutConsumer, topic, callback)
def direct_send(self, msg_id, msg):
"""Send a 'direct' message."""
self.publisher_send(DirectPublisher, msg_id, msg)
def topic_send(self, topic, msg, timeout=None):
"""Send a 'topic' message."""
#
# We want to create a message with attributes, e.g. a TTL. We
# don't really need to keep 'msg' in its JSON format any longer
# so let's create an actual qpid message here and get some
# value-add on the go.
#
# WARNING: Request timeout happens to be in the same units as
# qpid's TTL (seconds). If this changes in the future, then this
# will need to be altered accordingly.
#
qpid_message = qpid_messaging.Message(content=msg, ttl=timeout)
self.publisher_send(TopicPublisher, topic, qpid_message)
def fanout_send(self, topic, msg):
"""Send a 'fanout' message."""
self.publisher_send(FanoutPublisher, topic, msg)
def notify_send(self, topic, msg, **kwargs):
"""Send a notify message on a topic."""
self.publisher_send(NotifyPublisher, topic, msg)
def consume(self, limit=None):
"""Consume from all queues/consumers."""
it = self.iterconsume(limit=limit)
while True:
try:
it.next()
except StopIteration:
return
def consume_in_thread(self):
"""Consumer from all queues/consumers in a greenthread."""
@excutils.forever_retry_uncaught_exceptions
def _consumer_thread():
try:
self.consume()
except greenlet.GreenletExit:
return
if self.consumer_thread is None:
self.consumer_thread = eventlet.spawn(_consumer_thread)
return self.consumer_thread
def create_consumer(self, topic, proxy, fanout=False):
"""Create a consumer that calls a method in a proxy object."""
proxy_cb = rpc_amqp.ProxyCallback(
self.conf, proxy,
rpc_amqp.get_connection_pool(self.conf, Connection))
self.proxy_callbacks.append(proxy_cb)
if fanout:
consumer = FanoutConsumer(self.conf, self.session, topic, proxy_cb)
else:
consumer = TopicConsumer(self.conf, self.session, topic, proxy_cb)
self._register_consumer(consumer)
return consumer
def create_worker(self, topic, proxy, pool_name):
"""Create a worker that calls a method in a proxy object."""
proxy_cb = rpc_amqp.ProxyCallback(
self.conf, proxy,
rpc_amqp.get_connection_pool(self.conf, Connection))
self.proxy_callbacks.append(proxy_cb)
consumer = TopicConsumer(self.conf, self.session, topic, proxy_cb,
name=pool_name)
self._register_consumer(consumer)
return consumer
def join_consumer_pool(self, callback, pool_name, topic,
exchange_name=None, ack_on_error=True):
"""Register as a member of a group of consumers for a given topic from
the specified exchange.
Exactly one member of a given pool will receive each message.
A message will be delivered to multiple pools, if more than
one is created.
"""
callback_wrapper = rpc_amqp.CallbackWrapper(
conf=self.conf,
callback=callback,
connection_pool=rpc_amqp.get_connection_pool(self.conf,
Connection),
)
self.proxy_callbacks.append(callback_wrapper)
consumer = TopicConsumer(conf=self.conf,
session=self.session,
topic=topic,
callback=callback_wrapper,
name=pool_name,
exchange_name=exchange_name)
self._register_consumer(consumer)
return consumer
def create_connection(conf, new=True):
"""Create a connection."""
return rpc_amqp.create_connection(
conf, new,
rpc_amqp.get_connection_pool(conf, Connection))
def multicall(conf, context, topic, msg, timeout=None):
"""Make a call that returns multiple times."""
return rpc_amqp.multicall(
conf, context, topic, msg, timeout,
rpc_amqp.get_connection_pool(conf, Connection))
def call(conf, context, topic, msg, timeout=None):
"""Sends a message on a topic and wait for a response."""
return rpc_amqp.call(
conf, context, topic, msg, timeout,
rpc_amqp.get_connection_pool(conf, Connection))
def cast(conf, context, topic, msg):
"""Sends a message on a topic without waiting for a response."""
return rpc_amqp.cast(
conf, context, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection))
def fanout_cast(conf, context, topic, msg):
"""Sends a message on a fanout exchange without waiting for a response."""
return rpc_amqp.fanout_cast(
conf, context, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection))
def cast_to_server(conf, context, server_params, topic, msg):
"""Sends a message on a topic to a specific server."""
return rpc_amqp.cast_to_server(
conf, context, server_params, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection))
def fanout_cast_to_server(conf, context, server_params, topic, msg):
"""Sends a message on a fanout exchange to a specific server."""
return rpc_amqp.fanout_cast_to_server(
conf, context, server_params, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection))
def notify(conf, context, topic, msg, envelope):
"""Sends a notification event on a topic."""
return rpc_amqp.notify(conf, context, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection),
envelope)
def cleanup():
return rpc_amqp.cleanup(Connection.pool)

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# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 OpenStack Foundation
#
# 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 functools
import itertools
import socket
import ssl
import time
import uuid
import eventlet
import greenlet
import kombu
import kombu.connection
import kombu.entity
import kombu.messaging
from oslo.config import cfg
from openstack.common import excutils
from openstack.common.gettextutils import _ # noqa
from openstack.common import network_utils
from openstack.common.rpc import amqp as rpc_amqp
from openstack.common.rpc import common as rpc_common
from openstack.common import sslutils
kombu_opts = [
cfg.StrOpt('kombu_ssl_version',
default='',
help='SSL version to use (valid only if SSL enabled). '
'valid values are TLSv1, SSLv23 and SSLv3. SSLv2 may '
'be available on some distributions'
),
cfg.StrOpt('kombu_ssl_keyfile',
default='',
help='SSL key file (valid only if SSL enabled)'),
cfg.StrOpt('kombu_ssl_certfile',
default='',
help='SSL cert file (valid only if SSL enabled)'),
cfg.StrOpt('kombu_ssl_ca_certs',
default='',
help=('SSL certification authority file '
'(valid only if SSL enabled)')),
cfg.StrOpt('rabbit_host',
default='localhost',
help='The RabbitMQ broker address where a single node is used'),
cfg.IntOpt('rabbit_port',
default=5672,
help='The RabbitMQ broker port where a single node is used'),
cfg.ListOpt('rabbit_hosts',
default=['$rabbit_host:$rabbit_port'],
help='RabbitMQ HA cluster host:port pairs'),
cfg.BoolOpt('rabbit_use_ssl',
default=False,
help='connect over SSL for RabbitMQ'),
cfg.StrOpt('rabbit_userid',
default='guest',
help='the RabbitMQ userid'),
cfg.StrOpt('rabbit_password',
default='guest',
help='the RabbitMQ password',
secret=True),
cfg.StrOpt('rabbit_virtual_host',
default='/',
help='the RabbitMQ virtual host'),
cfg.IntOpt('rabbit_retry_interval',
default=1,
help='how frequently to retry connecting with RabbitMQ'),
cfg.IntOpt('rabbit_retry_backoff',
default=2,
help='how long to backoff for between retries when connecting '
'to RabbitMQ'),
cfg.IntOpt('rabbit_max_retries',
default=0,
help='maximum retries with trying to connect to RabbitMQ '
'(the default of 0 implies an infinite retry count)'),
cfg.BoolOpt('rabbit_ha_queues',
default=False,
help='use H/A queues in RabbitMQ (x-ha-policy: all).'
'You need to wipe RabbitMQ database when '
'changing this option.'),
]
cfg.CONF.register_opts(kombu_opts)
LOG = rpc_common.LOG
def _get_queue_arguments(conf):
"""Construct the arguments for declaring a queue.
If the rabbit_ha_queues option is set, we declare a mirrored queue
as described here:
http://www.rabbitmq.com/ha.html
Setting x-ha-policy to all means that the queue will be mirrored
to all nodes in the cluster.
"""
return {'x-ha-policy': 'all'} if conf.rabbit_ha_queues else {}
class ConsumerBase(object):
"""Consumer base class."""
def __init__(self, channel, callback, tag, **kwargs):
"""Declare a queue on an amqp channel.
'channel' is the amqp channel to use
'callback' is the callback to call when messages are received
'tag' is a unique ID for the consumer on the channel
queue name, exchange name, and other kombu options are
passed in here as a dictionary.
"""
self.callback = callback
self.tag = str(tag)
self.kwargs = kwargs
self.queue = None
self.ack_on_error = kwargs.get('ack_on_error', True)
self.reconnect(channel)
def reconnect(self, channel):
"""Re-declare the queue after a rabbit reconnect."""
self.channel = channel
self.kwargs['channel'] = channel
self.queue = kombu.entity.Queue(**self.kwargs)
self.queue.declare()
def _callback_handler(self, message, callback):
"""Call callback with deserialized message.
Messages that are processed without exception are ack'ed.
If the message processing generates an exception, it will be
ack'ed if ack_on_error=True. Otherwise it will be .reject()'ed.
Rejection is better than waiting for the message to timeout.
Rejected messages are immediately requeued.
"""
ack_msg = False
try:
msg = rpc_common.deserialize_msg(message.payload)
callback(msg)
ack_msg = True
except Exception:
if self.ack_on_error:
ack_msg = True
LOG.exception(_("Failed to process message"
" ... skipping it."))
else:
LOG.exception(_("Failed to process message"
" ... will requeue."))
finally:
if ack_msg:
message.ack()
else:
message.reject()
def consume(self, *args, **kwargs):
"""Actually declare the consumer on the amqp channel. This will
start the flow of messages from the queue. Using the
Connection.iterconsume() iterator will process the messages,
calling the appropriate callback.
If a callback is specified in kwargs, use that. Otherwise,
use the callback passed during __init__()
If kwargs['nowait'] is True, then this call will block until
a message is read.
"""
options = {'consumer_tag': self.tag}
options['nowait'] = kwargs.get('nowait', False)
callback = kwargs.get('callback', self.callback)
if not callback:
raise ValueError("No callback defined")
def _callback(raw_message):
message = self.channel.message_to_python(raw_message)
self._callback_handler(message, callback)
self.queue.consume(*args, callback=_callback, **options)
def cancel(self):
"""Cancel the consuming from the queue, if it has started."""
try:
self.queue.cancel(self.tag)
except KeyError as e:
# NOTE(comstud): Kludge to get around a amqplib bug
if str(e) != "u'%s'" % self.tag:
raise
self.queue = None
class DirectConsumer(ConsumerBase):
"""Queue/consumer class for 'direct'."""
def __init__(self, conf, channel, msg_id, callback, tag, **kwargs):
"""Init a 'direct' queue.
'channel' is the amqp channel to use
'msg_id' is the msg_id to listen on
'callback' is the callback to call when messages are received
'tag' is a unique ID for the consumer on the channel
Other kombu options may be passed
"""
# Default options
options = {'durable': False,
'queue_arguments': _get_queue_arguments(conf),
'auto_delete': True,
'exclusive': False}
options.update(kwargs)
exchange = kombu.entity.Exchange(name=msg_id,
type='direct',
durable=options['durable'],
auto_delete=options['auto_delete'])
super(DirectConsumer, self).__init__(channel,
callback,
tag,
name=msg_id,
exchange=exchange,
routing_key=msg_id,
**options)
class TopicConsumer(ConsumerBase):
"""Consumer class for 'topic'."""
def __init__(self, conf, channel, topic, callback, tag, name=None,
exchange_name=None, **kwargs):
"""Init a 'topic' queue.
:param channel: the amqp channel to use
:param topic: the topic to listen on
:paramtype topic: str
:param callback: the callback to call when messages are received
:param tag: a unique ID for the consumer on the channel
:param name: optional queue name, defaults to topic
:paramtype name: str
Other kombu options may be passed as keyword arguments
"""
# Default options
options = {'durable': conf.amqp_durable_queues,
'queue_arguments': _get_queue_arguments(conf),
'auto_delete': conf.amqp_auto_delete,
'exclusive': False}
options.update(kwargs)
exchange_name = exchange_name or rpc_amqp.get_control_exchange(conf)
exchange = kombu.entity.Exchange(name=exchange_name,
type='topic',
durable=options['durable'],
auto_delete=options['auto_delete'])
super(TopicConsumer, self).__init__(channel,
callback,
tag,
name=name or topic,
exchange=exchange,
routing_key=topic,
**options)
class FanoutConsumer(ConsumerBase):
"""Consumer class for 'fanout'."""
def __init__(self, conf, channel, topic, callback, tag, **kwargs):
"""Init a 'fanout' queue.
'channel' is the amqp channel to use
'topic' is the topic to listen on
'callback' is the callback to call when messages are received
'tag' is a unique ID for the consumer on the channel
Other kombu options may be passed
"""
unique = uuid.uuid4().hex
exchange_name = '%s_fanout' % topic
queue_name = '%s_fanout_%s' % (topic, unique)
# Default options
options = {'durable': False,
'queue_arguments': _get_queue_arguments(conf),
'auto_delete': True,
'exclusive': False}
options.update(kwargs)
exchange = kombu.entity.Exchange(name=exchange_name, type='fanout',
durable=options['durable'],
auto_delete=options['auto_delete'])
super(FanoutConsumer, self).__init__(channel, callback, tag,
name=queue_name,
exchange=exchange,
routing_key=topic,
**options)
class Publisher(object):
"""Base Publisher class."""
def __init__(self, channel, exchange_name, routing_key, **kwargs):
"""Init the Publisher class with the exchange_name, routing_key,
and other options
"""
self.exchange_name = exchange_name
self.routing_key = routing_key
self.kwargs = kwargs
self.reconnect(channel)
def reconnect(self, channel):
"""Re-establish the Producer after a rabbit reconnection."""
self.exchange = kombu.entity.Exchange(name=self.exchange_name,
**self.kwargs)
self.producer = kombu.messaging.Producer(exchange=self.exchange,
channel=channel,
routing_key=self.routing_key)
def send(self, msg, timeout=None):
"""Send a message."""
if timeout:
#
# AMQP TTL is in milliseconds when set in the header.
#
self.producer.publish(msg, headers={'ttl': (timeout * 1000)})
else:
self.producer.publish(msg)
class DirectPublisher(Publisher):
"""Publisher class for 'direct'."""
def __init__(self, conf, channel, msg_id, **kwargs):
"""init a 'direct' publisher.
Kombu options may be passed as keyword args to override defaults
"""
options = {'durable': False,
'auto_delete': True,
'exclusive': False}
options.update(kwargs)
super(DirectPublisher, self).__init__(channel, msg_id, msg_id,
type='direct', **options)
class TopicPublisher(Publisher):
"""Publisher class for 'topic'."""
def __init__(self, conf, channel, topic, **kwargs):
"""init a 'topic' publisher.
Kombu options may be passed as keyword args to override defaults
"""
options = {'durable': conf.amqp_durable_queues,
'auto_delete': conf.amqp_auto_delete,
'exclusive': False}
options.update(kwargs)
exchange_name = rpc_amqp.get_control_exchange(conf)
super(TopicPublisher, self).__init__(channel,
exchange_name,
topic,
type='topic',
**options)
class FanoutPublisher(Publisher):
"""Publisher class for 'fanout'."""
def __init__(self, conf, channel, topic, **kwargs):
"""init a 'fanout' publisher.
Kombu options may be passed as keyword args to override defaults
"""
options = {'durable': False,
'auto_delete': True,
'exclusive': False}
options.update(kwargs)
super(FanoutPublisher, self).__init__(channel, '%s_fanout' % topic,
None, type='fanout', **options)
class NotifyPublisher(TopicPublisher):
"""Publisher class for 'notify'."""
def __init__(self, conf, channel, topic, **kwargs):
self.durable = kwargs.pop('durable', conf.amqp_durable_queues)
self.queue_arguments = _get_queue_arguments(conf)
super(NotifyPublisher, self).__init__(conf, channel, topic, **kwargs)
def reconnect(self, channel):
super(NotifyPublisher, self).reconnect(channel)
# NOTE(jerdfelt): Normally the consumer would create the queue, but
# we do this to ensure that messages don't get dropped if the
# consumer is started after we do
queue = kombu.entity.Queue(channel=channel,
exchange=self.exchange,
durable=self.durable,
name=self.routing_key,
routing_key=self.routing_key,
queue_arguments=self.queue_arguments)
queue.declare()
class Connection(object):
"""Connection object."""
pool = None
def __init__(self, conf, server_params=None):
self.consumers = []
self.consumer_thread = None
self.proxy_callbacks = []
self.conf = conf
self.max_retries = self.conf.rabbit_max_retries
# Try forever?
if self.max_retries <= 0:
self.max_retries = None
self.interval_start = self.conf.rabbit_retry_interval
self.interval_stepping = self.conf.rabbit_retry_backoff
# max retry-interval = 30 seconds
self.interval_max = 30
self.memory_transport = False
if server_params is None:
server_params = {}
# Keys to translate from server_params to kombu params
server_params_to_kombu_params = {'username': 'userid'}
ssl_params = self._fetch_ssl_params()
params_list = []
for adr in self.conf.rabbit_hosts:
hostname, port = network_utils.parse_host_port(
adr, default_port=self.conf.rabbit_port)
params = {
'hostname': hostname,
'port': port,
'userid': self.conf.rabbit_userid,
'password': self.conf.rabbit_password,
'virtual_host': self.conf.rabbit_virtual_host,
}
for sp_key, value in server_params.iteritems():
p_key = server_params_to_kombu_params.get(sp_key, sp_key)
params[p_key] = value
if self.conf.fake_rabbit:
params['transport'] = 'memory'
if self.conf.rabbit_use_ssl:
params['ssl'] = ssl_params
params_list.append(params)
self.params_list = params_list
self.memory_transport = self.conf.fake_rabbit
self.connection = None
self.reconnect()
def _fetch_ssl_params(self):
"""Handles fetching what ssl params should be used for the connection
(if any).
"""
ssl_params = dict()
# http://docs.python.org/library/ssl.html - ssl.wrap_socket
if self.conf.kombu_ssl_version:
ssl_params['ssl_version'] = sslutils.validate_ssl_version(
self.conf.kombu_ssl_version)
if self.conf.kombu_ssl_keyfile:
ssl_params['keyfile'] = self.conf.kombu_ssl_keyfile
if self.conf.kombu_ssl_certfile:
ssl_params['certfile'] = self.conf.kombu_ssl_certfile
if self.conf.kombu_ssl_ca_certs:
ssl_params['ca_certs'] = self.conf.kombu_ssl_ca_certs
# We might want to allow variations in the
# future with this?
ssl_params['cert_reqs'] = ssl.CERT_REQUIRED
if not ssl_params:
# Just have the default behavior
return True
else:
# Return the extended behavior
return ssl_params
def _connect(self, params):
"""Connect to rabbit. Re-establish any queues that may have
been declared before if we are reconnecting. Exceptions should
be handled by the caller.
"""
if self.connection:
LOG.info(_("Reconnecting to AMQP server on "
"%(hostname)s:%(port)d") % params)
try:
self.connection.release()
except self.connection_errors:
pass
# Setting this in case the next statement fails, though
# it shouldn't be doing any network operations, yet.
self.connection = None
self.connection = kombu.connection.BrokerConnection(**params)
self.connection_errors = self.connection.connection_errors
if self.memory_transport:
# Kludge to speed up tests.
self.connection.transport.polling_interval = 0.0
self.consumer_num = itertools.count(1)
self.connection.connect()
self.channel = self.connection.channel()
# work around 'memory' transport bug in 1.1.3
if self.memory_transport:
self.channel._new_queue('ae.undeliver')
for consumer in self.consumers:
consumer.reconnect(self.channel)
LOG.info(_('Connected to AMQP server on %(hostname)s:%(port)d') %
params)
def reconnect(self):
"""Handles reconnecting and re-establishing queues.
Will retry up to self.max_retries number of times.
self.max_retries = 0 means to retry forever.
Sleep between tries, starting at self.interval_start
seconds, backing off self.interval_stepping number of seconds
each attempt.
"""
attempt = 0
while True:
params = self.params_list[attempt % len(self.params_list)]
attempt += 1
try:
self._connect(params)
return
except (IOError, self.connection_errors) as e:
pass
except Exception as e:
# NOTE(comstud): Unfortunately it's possible for amqplib
# to return an error not covered by its transport
# connection_errors in the case of a timeout waiting for
# a protocol response. (See paste link in LP888621)
# So, we check all exceptions for 'timeout' in them
# and try to reconnect in this case.
if 'timeout' not in str(e):
raise
log_info = {}
log_info['err_str'] = str(e)
log_info['max_retries'] = self.max_retries
log_info.update(params)
if self.max_retries and attempt == self.max_retries:
msg = _('Unable to connect to AMQP server on '
'%(hostname)s:%(port)d after %(max_retries)d '
'tries: %(err_str)s') % log_info
LOG.error(msg)
raise rpc_common.RPCException(msg)
if attempt == 1:
sleep_time = self.interval_start or 1
elif attempt > 1:
sleep_time += self.interval_stepping
if self.interval_max:
sleep_time = min(sleep_time, self.interval_max)
log_info['sleep_time'] = sleep_time
LOG.error(_('AMQP server on %(hostname)s:%(port)d is '
'unreachable: %(err_str)s. Trying again in '
'%(sleep_time)d seconds.') % log_info)
time.sleep(sleep_time)
def ensure(self, error_callback, method, *args, **kwargs):
while True:
try:
return method(*args, **kwargs)
except (self.connection_errors, socket.timeout, IOError) as e:
if error_callback:
error_callback(e)
except Exception as e:
# NOTE(comstud): Unfortunately it's possible for amqplib
# to return an error not covered by its transport
# connection_errors in the case of a timeout waiting for
# a protocol response. (See paste link in LP888621)
# So, we check all exceptions for 'timeout' in them
# and try to reconnect in this case.
if 'timeout' not in str(e):
raise
if error_callback:
error_callback(e)
self.reconnect()
def get_channel(self):
"""Convenience call for bin/clear_rabbit_queues."""
return self.channel
def close(self):
"""Close/release this connection."""
self.cancel_consumer_thread()
self.wait_on_proxy_callbacks()
self.connection.release()
self.connection = None
def reset(self):
"""Reset a connection so it can be used again."""
self.cancel_consumer_thread()
self.wait_on_proxy_callbacks()
self.channel.close()
self.channel = self.connection.channel()
# work around 'memory' transport bug in 1.1.3
if self.memory_transport:
self.channel._new_queue('ae.undeliver')
self.consumers = []
def declare_consumer(self, consumer_cls, topic, callback):
"""Create a Consumer using the class that was passed in and
add it to our list of consumers
"""
def _connect_error(exc):
log_info = {'topic': topic, 'err_str': str(exc)}
LOG.error(_("Failed to declare consumer for topic '%(topic)s': "
"%(err_str)s") % log_info)
def _declare_consumer():
consumer = consumer_cls(self.conf, self.channel, topic, callback,
self.consumer_num.next())
self.consumers.append(consumer)
return consumer
return self.ensure(_connect_error, _declare_consumer)
def iterconsume(self, limit=None, timeout=None):
"""Return an iterator that will consume from all queues/consumers."""
info = {'do_consume': True}
def _error_callback(exc):
if isinstance(exc, socket.timeout):
LOG.debug(_('Timed out waiting for RPC response: %s') %
str(exc))
raise rpc_common.Timeout()
else:
LOG.exception(_('Failed to consume message from queue: %s') %
str(exc))
info['do_consume'] = True
def _consume():
if info['do_consume']:
queues_head = self.consumers[:-1] # not fanout.
queues_tail = self.consumers[-1] # fanout
for queue in queues_head:
queue.consume(nowait=True)
queues_tail.consume(nowait=False)
info['do_consume'] = False
return self.connection.drain_events(timeout=timeout)
for iteration in itertools.count(0):
if limit and iteration >= limit:
raise StopIteration
yield self.ensure(_error_callback, _consume)
def cancel_consumer_thread(self):
"""Cancel a consumer thread."""
if self.consumer_thread is not None:
self.consumer_thread.kill()
try:
self.consumer_thread.wait()
except greenlet.GreenletExit:
pass
self.consumer_thread = None
def wait_on_proxy_callbacks(self):
"""Wait for all proxy callback threads to exit."""
for proxy_cb in self.proxy_callbacks:
proxy_cb.wait()
def publisher_send(self, cls, topic, msg, timeout=None, **kwargs):
"""Send to a publisher based on the publisher class."""
def _error_callback(exc):
log_info = {'topic': topic, 'err_str': str(exc)}
LOG.exception(_("Failed to publish message to topic "
"'%(topic)s': %(err_str)s") % log_info)
def _publish():
publisher = cls(self.conf, self.channel, topic, **kwargs)
publisher.send(msg, timeout)
self.ensure(_error_callback, _publish)
def declare_direct_consumer(self, topic, callback):
"""Create a 'direct' queue.
In nova's use, this is generally a msg_id queue used for
responses for call/multicall
"""
self.declare_consumer(DirectConsumer, topic, callback)
def declare_topic_consumer(self, topic, callback=None, queue_name=None,
exchange_name=None, ack_on_error=True):
"""Create a 'topic' consumer."""
self.declare_consumer(functools.partial(TopicConsumer,
name=queue_name,
exchange_name=exchange_name,
ack_on_error=ack_on_error,
),
topic, callback)
def declare_fanout_consumer(self, topic, callback):
"""Create a 'fanout' consumer."""
self.declare_consumer(FanoutConsumer, topic, callback)
def direct_send(self, msg_id, msg):
"""Send a 'direct' message."""
self.publisher_send(DirectPublisher, msg_id, msg)
def topic_send(self, topic, msg, timeout=None):
"""Send a 'topic' message."""
self.publisher_send(TopicPublisher, topic, msg, timeout)
def fanout_send(self, topic, msg):
"""Send a 'fanout' message."""
self.publisher_send(FanoutPublisher, topic, msg)
def notify_send(self, topic, msg, **kwargs):
"""Send a notify message on a topic."""
self.publisher_send(NotifyPublisher, topic, msg, None, **kwargs)
def consume(self, limit=None):
"""Consume from all queues/consumers."""
it = self.iterconsume(limit=limit)
while True:
try:
it.next()
except StopIteration:
return
def consume_in_thread(self):
"""Consumer from all queues/consumers in a greenthread."""
@excutils.forever_retry_uncaught_exceptions
def _consumer_thread():
try:
self.consume()
except greenlet.GreenletExit:
return
if self.consumer_thread is None:
self.consumer_thread = eventlet.spawn(_consumer_thread)
return self.consumer_thread
def create_consumer(self, topic, proxy, fanout=False):
"""Create a consumer that calls a method in a proxy object."""
proxy_cb = rpc_amqp.ProxyCallback(
self.conf, proxy,
rpc_amqp.get_connection_pool(self.conf, Connection))
self.proxy_callbacks.append(proxy_cb)
if fanout:
self.declare_fanout_consumer(topic, proxy_cb)
else:
self.declare_topic_consumer(topic, proxy_cb)
def create_worker(self, topic, proxy, pool_name):
"""Create a worker that calls a method in a proxy object."""
proxy_cb = rpc_amqp.ProxyCallback(
self.conf, proxy,
rpc_amqp.get_connection_pool(self.conf, Connection))
self.proxy_callbacks.append(proxy_cb)
self.declare_topic_consumer(topic, proxy_cb, pool_name)
def join_consumer_pool(self, callback, pool_name, topic,
exchange_name=None, ack_on_error=True):
"""Register as a member of a group of consumers for a given topic from
the specified exchange.
Exactly one member of a given pool will receive each message.
A message will be delivered to multiple pools, if more than
one is created.
"""
callback_wrapper = rpc_amqp.CallbackWrapper(
conf=self.conf,
callback=callback,
connection_pool=rpc_amqp.get_connection_pool(self.conf,
Connection),
)
self.proxy_callbacks.append(callback_wrapper)
self.declare_topic_consumer(
queue_name=pool_name,
topic=topic,
exchange_name=exchange_name,
callback=callback_wrapper,
ack_on_error=ack_on_error,
)
def create_connection(conf, new=True):
"""Create a connection."""
return rpc_amqp.create_connection(
conf, new,
rpc_amqp.get_connection_pool(conf, Connection))
def multicall(conf, context, topic, msg, timeout=None):
"""Make a call that returns multiple times."""
return rpc_amqp.multicall(
conf, context, topic, msg, timeout,
rpc_amqp.get_connection_pool(conf, Connection))
def call(conf, context, topic, msg, timeout=None):
"""Sends a message on a topic and wait for a response."""
return rpc_amqp.call(
conf, context, topic, msg, timeout,
rpc_amqp.get_connection_pool(conf, Connection))
def cast(conf, context, topic, msg):
"""Sends a message on a topic without waiting for a response."""
return rpc_amqp.cast(
conf, context, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection))
def fanout_cast(conf, context, topic, msg):
"""Sends a message on a fanout exchange without waiting for a response."""
return rpc_amqp.fanout_cast(
conf, context, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection))
def cast_to_server(conf, context, server_params, topic, msg):
"""Sends a message on a topic to a specific server."""
return rpc_amqp.cast_to_server(
conf, context, server_params, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection))
def fanout_cast_to_server(conf, context, server_params, topic, msg):
"""Sends a message on a fanout exchange to a specific server."""
return rpc_amqp.fanout_cast_to_server(
conf, context, server_params, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection))
def notify(conf, context, topic, msg, envelope):
"""Sends a notification event on a topic."""
return rpc_amqp.notify(
conf, context, topic, msg,
rpc_amqp.get_connection_pool(conf, Connection),
envelope)
def cleanup():
return rpc_amqp.cleanup(Connection.pool)