# 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 logging
import random
import socket
import ssl
import time
import uuid
import kombu
import kombu.connection
import kombu.entity
import kombu.messaging
import six
from oslo.config import cfg
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._i18n import _
from oslo.messaging import exceptions
from oslo.utils import netutils
rabbit_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.FloatOpt('kombu_reconnect_delay',
default=1.0,
help='How long to wait before reconnecting in response to an '
'AMQP consumer cancel notification.'),
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_login_method',
default='AMQPLAIN',
help='The RabbitMQ login method.'),
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 number of RabbitMQ connection retries. '
'Default is 0 (infinite retry count).'),
cfg.BoolOpt('rabbit_ha_queues',
default=False,
help='Use HA queues in RabbitMQ (x-ha-policy: all). '
'If you change this option, you must wipe the '
'RabbitMQ database.'),
# FIXME(markmc): this was toplevel in openstack.common.rpc
cfg.BoolOpt('fake_rabbit',
default=False,
help='If passed, use a fake RabbitMQ provider.'),
]
LOG = logging.getLogger(__name__)
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 RabbitMessage(dict):
def __init__(self, raw_message):
super(RabbitMessage, self).__init__(
rpc_common.deserialize_msg(raw_message.payload))
self._raw_message = raw_message
def acknowledge(self):
self._raw_message.ack()
def requeue(self):
self._raw_message.requeue()
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 = six.text_type(tag)
self.kwargs = kwargs
self.queue = None
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 and ack'ed.
"""
try:
callback(RabbitMessage(message))
except Exception:
LOG.exception(_("Failed to process message"
" ... skipping it."))
message.ack()
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 six.text_type(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, exchange_name,
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 exchange_name: the exchange name to use
: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 = 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, topic, **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, topic, topic,
type='direct', **options)
class TopicPublisher(Publisher):
"""Publisher class for 'topic'."""
def __init__(self, conf, channel, exchange_name, 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)
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, exchange_name, topic, **kwargs):
self.durable = kwargs.pop('durable', conf.amqp_durable_queues)
self.queue_arguments = _get_queue_arguments(conf)
super(NotifyPublisher, self).__init__(conf, channel, exchange_name,
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."""
pools = {}
def __init__(self, conf, url):
self.consumers = []
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
ssl_params = self._fetch_ssl_params()
if url.virtual_host is not None:
virtual_host = url.virtual_host
else:
virtual_host = self.conf.rabbit_virtual_host
self.brokers_params = []
if url.hosts:
for host in url.hosts:
params = {
'hostname': host.hostname,
'port': host.port or 5672,
'userid': host.username or '',
'password': host.password or '',
'login_method': self.conf.rabbit_login_method,
'virtual_host': virtual_host
}
if self.conf.fake_rabbit:
params['transport'] = 'memory'
if self.conf.rabbit_use_ssl:
params['ssl'] = ssl_params
self.brokers_params.append(params)
else:
# Old configuration format
for adr in self.conf.rabbit_hosts:
hostname, port = netutils.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,
'login_method': self.conf.rabbit_login_method,
'virtual_host': virtual_host
}
if self.conf.fake_rabbit:
params['transport'] = 'memory'
if self.conf.rabbit_use_ssl:
params['ssl'] = ssl_params
self.brokers_params.append(params)
random.shuffle(self.brokers_params)
self.brokers = itertools.cycle(self.brokers_params)
self.memory_transport = self.conf.fake_rabbit
self.connection = None
self.do_consume = None
self.reconnect()
# FIXME(markmc): use oslo sslutils when it is available as a library
_SSL_PROTOCOLS = {
"tlsv1": ssl.PROTOCOL_TLSv1,
"sslv23": ssl.PROTOCOL_SSLv23,
"sslv3": ssl.PROTOCOL_SSLv3
}
try:
_SSL_PROTOCOLS["sslv2"] = ssl.PROTOCOL_SSLv2
except AttributeError:
pass
@classmethod
def validate_ssl_version(cls, version):
key = version.lower()
try:
return cls._SSL_PROTOCOLS[key]
except KeyError:
raise RuntimeError(_("Invalid SSL version : %s") % version)
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'] = self.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
# Return the extended behavior or just have the default behavior
return ssl_params or True
def _connect(self, broker):
"""Connect to rabbit. Re-establish any queues that may have
been declared before if we are reconnecting. Exceptions should
be handled by the caller.
"""
LOG.info(_("Connecting to AMQP server on "
"%(hostname)s:%(port)d"), broker)
self.connection = kombu.connection.BrokerConnection(**broker)
self.connection_errors = self.connection.connection_errors
self.channel_errors = self.connection.channel_errors
if self.memory_transport:
# Kludge to speed up tests.
self.connection.transport.polling_interval = 0.0
self.do_consume = True
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'),
broker)
def _disconnect(self):
if self.connection:
# XXX(nic): when reconnecting to a RabbitMQ cluster
# with mirrored queues in use, the attempt to release the
# connection can hang "indefinitely" somewhere deep down
# in Kombu. Blocking the thread for a bit prior to
# release seems to kludge around the problem where it is
# otherwise reproduceable.
if self.conf.kombu_reconnect_delay > 0:
LOG.info(_("Delaying reconnect for %1.1f seconds...") %
self.conf.kombu_reconnect_delay)
time.sleep(self.conf.kombu_reconnect_delay)
try:
self.connection.release()
except self.connection_errors:
pass
self.connection = None
def reconnect(self, retry=None):
"""Handles reconnecting and re-establishing queues.
Will retry up to retry number of times.
retry = None means use the value of rabbit_max_retries
retry = -1 means to retry forever
retry = 0 means no retry
retry = N means N retries
Sleep between tries, starting at self.interval_start
seconds, backing off self.interval_stepping number of seconds
each attempt.
"""
attempt = 0
loop_forever = False
if retry is None:
retry = self.max_retries
if retry is None or retry < 0:
loop_forever = True
while True:
self._disconnect()
broker = six.next(self.brokers)
attempt += 1
try:
self._connect(broker)
return
except IOError as ex:
e = ex
except self.connection_errors as ex:
e = ex
except Exception as ex:
# 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 six.text_type(e):
raise
e = ex
log_info = {}
log_info['err_str'] = e
log_info['retry'] = retry or 0
log_info.update(broker)
if not loop_forever and attempt > retry:
msg = _('Unable to connect to AMQP server on '
'%(hostname)s:%(port)d after %(retry)d '
'tries: %(err_str)s') % log_info
LOG.error(msg)
raise exceptions.MessageDeliveryFailure(msg)
else:
if attempt == 1:
sleep_time = self.interval_start or 1
elif attempt > 1:
sleep_time += self.interval_stepping
sleep_time = min(sleep_time, self.interval_max)
log_info['sleep_time'] = sleep_time
if 'Socket closed' in six.text_type(e):
LOG.error(_('AMQP server %(hostname)s:%(port)d closed'
' the connection. Check login credentials:'
' %(err_str)s'), log_info)
else:
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, retry=None):
while True:
try:
return method()
except self.connection_errors as e:
if error_callback:
error_callback(e)
except self.channel_errors as e:
if error_callback:
error_callback(e)
except (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 six.text_type(e):
raise
if error_callback:
error_callback(e)
self.reconnect(retry=retry)
def get_channel(self):
"""Convenience call for bin/clear_rabbit_queues."""
return self.channel
def close(self):
"""Close/release this connection."""
if self.connection:
self.connection.release()
self.connection = None
def reset(self):
"""Reset a connection so it can be used again."""
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': 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,
six.next(self.consumer_num))
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."""
def _error_callback(exc):
if isinstance(exc, socket.timeout):
LOG.debug('Timed out waiting for RPC response: %s', exc)
raise rpc_common.Timeout()
else:
LOG.exception(_('Failed to consume message from queue: %s'),
exc)
self.do_consume = True
def _consume():
if self.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)
self.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 publisher_send(self, cls, topic, msg, timeout=None, retry=None,
**kwargs):
"""Send to a publisher based on the publisher class."""
def _error_callback(exc):
log_info = {'topic': topic, 'err_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=topic, **kwargs)
publisher.send(msg, timeout)
self.ensure(_error_callback, _publish, retry=retry)
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, exchange_name, topic, callback=None,
queue_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, exchange_name, topic, msg, timeout=None, retry=None):
"""Send a 'topic' message."""
self.publisher_send(TopicPublisher, topic, msg, timeout,
exchange_name=exchange_name, retry=retry)
def fanout_send(self, topic, msg, retry=None):
"""Send a 'fanout' message."""
self.publisher_send(FanoutPublisher, topic, msg, retry=retry)
def notify_send(self, exchange_name, topic, msg, retry=None, **kwargs):
"""Send a notify message on a topic."""
self.publisher_send(NotifyPublisher, topic, msg, timeout=None,
exchange_name=exchange_name, retry=retry, **kwargs)
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 RabbitDriver(amqpdriver.AMQPDriverBase):
def __init__(self, conf, url,
default_exchange=None,
allowed_remote_exmods=None):
conf.register_opts(rabbit_opts)
conf.register_opts(rpc_amqp.amqp_opts)
connection_pool = rpc_amqp.get_connection_pool(conf, url, Connection)
super(RabbitDriver, self).__init__(conf, url,
connection_pool,
default_exchange,
allowed_remote_exmods)
def require_features(self, requeue=True):
pass