# 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 logging import time from oslo.config import cfg import six from oslo.messaging._drivers import amqp as rpc_amqp from oslo.messaging._drivers import amqpdriver from oslo.messaging._drivers import common as rpc_common from oslo.messaging.openstack.common import importutils from oslo.messaging.openstack.common import jsonutils # FIXME(markmc): remove this _ = lambda s: s 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='Whether to disable the Nagle algorithm.'), # NOTE(russellb) If any additional versions are added (beyond 1 and 2), # this file could probably use some additional refactoring so that the # differences between each version are split into different classes. cfg.IntOpt('qpid_topology_version', default=1, help="The qpid topology version to use. Version 1 is what " "was originally used by impl_qpid. Version 2 includes " "some backwards-incompatible changes that allow broker " "federation to work. Users should update to version 2 " "when they are able to take everything down, as it " "requires a clean break."), ] JSON_CONTENT_TYPE = 'application/json; charset=utf8' def raise_invalid_topology_version(conf): msg = (_("Invalid value for qpid_topology_version: %d") % conf.qpid_topology_version) LOG.error(msg) raise Exception(msg) class QpidMessage(dict): def __init__(self, session, raw_message): super(QpidMessage, self).__init__( rpc_common.deserialize_msg(raw_message.content)) self._raw_message = raw_message self._session = session def acknowledge(self): self._session.acknowledge(self._raw_message) def requeue(self): pass class ConsumerBase(object): """Consumer base class.""" def __init__(self, conf, 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 if conf.qpid_topology_version == 1: addr_opts = { "create": "always", "node": { "type": "topic", "x-declare": { "durable": True, "auto-delete": True, }, }, "link": { "durable": True, "x-declare": { "durable": False, "auto-delete": True, "exclusive": False, }, }, } addr_opts["node"]["x-declare"].update(node_opts) elif conf.qpid_topology_version == 2: addr_opts = { "link": { "x-declare": { "auto-delete": True, "exclusive": False, }, }, } else: raise_invalid_topology_version(conf) addr_opts["link"]["x-declare"].update(link_opts) if link_name: addr_opts["link"]["name"] = link_name self.address = "%s ; %s" % (node_name, jsonutils.dumps(addr_opts)) self.connect(session) def connect(self, session): """Declare the receiver 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) self.callback(QpidMessage(self.session, message)) except Exception: LOG.exception(_("Failed to process message... skipping it.")) 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 """ link_opts = { "auto-delete": conf.amqp_auto_delete, "exclusive": True, "durable": conf.amqp_durable_queues, } if conf.qpid_topology_version == 1: node_name = "%s/%s" % (msg_id, msg_id) node_opts = {"type": "direct"} link_name = msg_id elif conf.qpid_topology_version == 2: node_name = "amq.direct/%s" % msg_id node_opts = {} link_name = msg_id else: raise_invalid_topology_version(conf) super(DirectConsumer, self).__init__(conf, session, callback, node_name, node_opts, link_name, link_opts) 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) link_opts = { "auto-delete": conf.amqp_auto_delete, "durable": conf.amqp_durable_queues, } if conf.qpid_topology_version == 1: node_name = "%s/%s" % (exchange_name, topic) elif conf.qpid_topology_version == 2: node_name = "amq.topic/topic/%s/%s" % (exchange_name, topic) else: raise_invalid_topology_version(conf) super(TopicConsumer, self).__init__(conf, session, callback, node_name, {}, name or topic, link_opts) 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 link_opts = {"exclusive": True} if conf.qpid_topology_version == 1: node_name = "%s_fanout" % topic node_opts = {"durable": False, "type": "fanout"} elif conf.qpid_topology_version == 2: node_name = "amq.topic/fanout/%s" % topic node_opts = {} else: raise_invalid_topology_version(conf) super(FanoutConsumer, self).__init__(conf, session, callback, node_name, node_opts, None, link_opts) class Publisher(object): """Base Publisher class.""" def __init__(self, conf, 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 if conf.qpid_topology_version == 1: 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)) elif conf.qpid_topology_version == 2: self.address = node_name else: raise_invalid_topology_version(conf) 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.""" if conf.qpid_topology_version == 1: node_name = "%s/%s" % (msg_id, msg_id) node_opts = {"type": "direct"} elif conf.qpid_topology_version == 2: node_name = "amq.direct/%s" % msg_id node_opts = {} else: raise_invalid_topology_version(conf) super(DirectPublisher, self).__init__(conf, session, node_name, node_opts) 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) if conf.qpid_topology_version == 1: node_name = "%s/%s" % (exchange_name, topic) elif conf.qpid_topology_version == 2: node_name = "amq.topic/topic/%s/%s" % (exchange_name, topic) else: raise_invalid_topology_version(conf) super(TopicPublisher, self).__init__(conf, session, node_name) class FanoutPublisher(Publisher): """Publisher class for 'fanout'.""" def __init__(self, conf, session, topic): """Init a 'fanout' publisher. """ if conf.qpid_topology_version == 1: node_name = "%s_fanout" % topic node_opts = {"type": "fanout"} elif conf.qpid_topology_version == 2: node_name = "amq.topic/fanout/%s" % topic node_opts = {} else: raise_invalid_topology_version(conf) super(FanoutPublisher, self).__init__(conf, session, node_name, node_opts) 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) node_opts = {"durable": True} if conf.qpid_topology_version == 1: node_name = "%s/%s" % (exchange_name, topic) elif conf.qpid_topology_version == 2: node_name = "amq.topic/topic/%s/%s" % (exchange_name, topic) else: raise_invalid_topology_version(conf) super(NotifyPublisher, self).__init__(conf, session, node_name, node_opts) 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.connection = None self.session = None self.consumers = {} 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 = itertools.cycle(params['qpid_hosts']) self.username = params['username'] self.password = params['password'] 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.""" delay = 1 while True: # Close the session if necessary if self.connection is not None and self.connection.opened(): try: self.connection.close() except qpid_exceptions.MessagingError: pass broker = six.next(self.brokers) try: self.connection_create(broker) self.connection.open() except qpid_exceptions.MessagingError 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(delay + 1, 5) 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 six.itervalues(consumers): 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.MessagingError) as e: if error_callback: error_callback(e) self.reconnect() def close(self): """Close/release this connection.""" 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.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 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, timeout=None): """Consume from all queues/consumers.""" it = self.iterconsume(limit=limit, timeout=timeout) while True: try: six.next(it) except StopIteration: return class QpidDriver(amqpdriver.AMQPDriverBase): def __init__(self, conf, url, default_exchange=None, allowed_remote_exmods=[]): conf.register_opts(qpid_opts) conf.register_opts(rpc_amqp.amqp_opts) connection_pool = rpc_amqp.get_connection_pool(conf, Connection) super(QpidDriver, self).__init__(conf, url, connection_pool, default_exchange, allowed_remote_exmods)