# Copyright 2010 United States Government as represented by the # Administrator of the National Aeronautics and Space Administration. # All Rights Reserved. # Copyright 2013 Red Hat, Inc. # Copyright (c) 2012 Rackspace Hosting # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. import logging from debtcollector import removals from oslo_config import cfg from stevedore import driver from urllib import parse from oslo_messaging import exceptions __all__ = [ 'DriverLoadFailure', 'InvalidTransportURL', 'Transport', 'TransportHost', 'TransportURL', 'TransportOptions', 'get_transport', 'set_transport_defaults', ] LOG = logging.getLogger(__name__) _transport_opts = [ cfg.StrOpt('transport_url', default="rabbit://", secret=True, help='The network address and optional user credentials for ' 'connecting to the messaging backend, in URL format. The ' 'expected format is:\n\n' 'driver://[user:pass@]host:port[,[userN:passN@]hostN:' 'portN]/virtual_host?query\n\n' 'Example: rabbit://rabbitmq:password@127.0.0.1:5672//\n\n' 'For full details on the fields in the URL see the ' 'documentation of oslo_messaging.TransportURL at ' 'https://docs.openstack.org/oslo.messaging/latest/' 'reference/transport.html'), cfg.StrOpt('control_exchange', default='openstack', help='The default exchange under which topics are scoped. May ' 'be overridden by an exchange name specified in the ' 'transport_url option.'), ] def set_transport_defaults(control_exchange): """Set defaults for messaging transport configuration options. :param control_exchange: the default exchange under which topics are scoped :type control_exchange: str """ cfg.set_defaults(_transport_opts, control_exchange=control_exchange) class Transport(object): """A messaging transport. This is a mostly opaque handle for an underlying messaging transport driver. RPCs and Notifications may use separate messaging systems that utilize different drivers, access permissions, message delivery, etc. To ensure the correct messaging functionality, the corresponding method should be used to construct a Transport object from transport configuration gleaned from the user's configuration and, optionally, a transport URL. The factory method for RPC Transport objects:: def get_rpc_transport(conf, url=None, allowed_remote_exmods=None) If a transport URL is supplied as a parameter, any transport configuration contained in it takes precedence. If no transport URL is supplied, but there is a transport URL supplied in the user's configuration then that URL will take the place of the URL parameter. The factory method for Notification Transport objects:: def get_notification_transport(conf, url=None, allowed_remote_exmods=None) If no transport URL is provided, the URL in the notifications section of the config file will be used. If that URL is also absent, the same transport as specified in the user's default section will be used. The Transport has a single 'conf' property which is the cfg.ConfigOpts instance used to construct the transport object. """ def __init__(self, driver): self.conf = driver.conf self._driver = driver def _require_driver_features(self, requeue=False): self._driver.require_features(requeue=requeue) def _send(self, target, ctxt, message, wait_for_reply=None, timeout=None, call_monitor_timeout=None, retry=None, transport_options=None): if not target.topic: raise exceptions.InvalidTarget('A topic is required to send', target) return self._driver.send(target, ctxt, message, wait_for_reply=wait_for_reply, timeout=timeout, call_monitor_timeout=call_monitor_timeout, retry=retry, transport_options=transport_options) def _send_notification(self, target, ctxt, message, version, retry=None): if not target.topic: raise exceptions.InvalidTarget('A topic is required to send', target) self._driver.send_notification(target, ctxt, message, version, retry=retry) def _listen(self, target, batch_size, batch_timeout): if not (target.topic and target.server): raise exceptions.InvalidTarget('A server\'s target must have ' 'topic and server names specified', target) return self._driver.listen(target, batch_size, batch_timeout) def _listen_for_notifications(self, targets_and_priorities, pool, batch_size, batch_timeout): for target, priority in targets_and_priorities: if not target.topic: raise exceptions.InvalidTarget('A target must have ' 'topic specified', target) return self._driver.listen_for_notifications( targets_and_priorities, pool, batch_size, batch_timeout ) def cleanup(self): """Release all resources associated with this transport.""" self._driver.cleanup() class RPCTransport(Transport): """Transport object for RPC.""" def __init__(self, driver): super(RPCTransport, self).__init__(driver) class NotificationTransport(Transport): """Transport object for notifications.""" def __init__(self, driver): super(NotificationTransport, self).__init__(driver) class InvalidTransportURL(exceptions.MessagingException): """Raised if transport URL is invalid.""" def __init__(self, url, msg): super(InvalidTransportURL, self).__init__(msg) self.url = url class DriverLoadFailure(exceptions.MessagingException): """Raised if a transport driver can't be loaded.""" def __init__(self, driver, ex): msg = 'Failed to load transport driver "%s": %s' % (driver, ex) super(DriverLoadFailure, self).__init__(msg) self.driver = driver self.ex = ex def _get_transport(conf, url=None, allowed_remote_exmods=None, transport_cls=RPCTransport): allowed_remote_exmods = allowed_remote_exmods or [] conf.register_opts(_transport_opts) if not isinstance(url, TransportURL): url = TransportURL.parse(conf, url) kwargs = dict(default_exchange=conf.control_exchange, allowed_remote_exmods=allowed_remote_exmods) try: mgr = driver.DriverManager('oslo.messaging.drivers', url.transport.split('+')[0], invoke_on_load=True, invoke_args=[conf, url], invoke_kwds=kwargs) except RuntimeError as ex: raise DriverLoadFailure(url.transport, ex) return transport_cls(mgr.driver) @removals.remove( message='use get_rpc_transport or get_notification_transport' ) def get_transport(conf, url=None, allowed_remote_exmods=None): """A factory method for Transport objects. This method will construct a Transport object from transport configuration gleaned from the user's configuration and, optionally, a transport URL. If a transport URL is supplied as a parameter, any transport configuration contained in it takes precedence. If no transport URL is supplied, but there is a transport URL supplied in the user's configuration then that URL will take the place of the URL parameter. In both cases, any configuration not supplied in the transport URL may be taken from individual configuration parameters in the user's configuration. An example transport URL might be:: rabbit://me:passwd@host:5672/virtual_host and can either be passed as a string or a TransportURL object. :param conf: the user configuration :type conf: cfg.ConfigOpts :param url: a transport URL, see :py:class:`transport.TransportURL` :type url: str or TransportURL :param allowed_remote_exmods: a list of modules which a client using this transport will deserialize remote exceptions from :type allowed_remote_exmods: list """ return _get_transport(conf, url, allowed_remote_exmods, transport_cls=RPCTransport) class TransportHost(object): """A host element of a parsed transport URL.""" def __init__(self, hostname=None, port=None, username=None, password=None): self.hostname = hostname self.port = port self.username = username self.password = password def __hash__(self): return hash((self.hostname, self.port, self.username, self.password)) def __eq__(self, other): return vars(self) == vars(other) def __ne__(self, other): return not self == other def __repr__(self): attrs = [] for a in ['hostname', 'port', 'username', 'password']: v = getattr(self, a) if v: attrs.append((a, repr(v))) values = ', '.join(['%s=%s' % i for i in attrs]) return '' class TransportOptions(object): def __init__(self, at_least_once=False): self._at_least_once = at_least_once @property def at_least_once(self): return self._at_least_once class TransportURL(object): """A parsed transport URL. Transport URLs take the form:: driver://[user:pass@]host:port[,[userN:passN@]hostN:portN]/virtual_host?query where: driver Specifies the transport driver to use. Typically this is `rabbit` for the RabbitMQ broker. See the documentation for other available transport drivers. [user:pass@]host:port Specifies the network location of the broker. `user` and `pass` are the optional username and password used for authentication with the broker. `user` and `pass` may contain any of the following ASCII characters: * Alphabetic (a-z and A-Z) * Numeric (0-9) * Special characters: & = $ - _ . + ! * ( ) `user` may include at most one `@` character for compatibility with some implementations of SASL. All other characters in `user` and `pass` must be encoded via '%nn' You may include multiple different network locations separated by commas. The client will connect to any of the available locations and will automatically fail over to another should the connection fail. virtual_host Specifies the "virtual host" within the broker. Support for virtual hosts is specific to the message bus used. query Permits passing driver-specific options which override the corresponding values from the configuration file. :param conf: a ConfigOpts instance :type conf: oslo.config.cfg.ConfigOpts :param transport: a transport name for example 'rabbit' :type transport: str :param virtual_host: a virtual host path for example '/' :type virtual_host: str :param hosts: a list of TransportHost objects :type hosts: list :param query: a dictionary of URL query parameters :type query: dict """ def __init__(self, conf, transport=None, virtual_host=None, hosts=None, query=None): self.conf = conf self.conf.register_opts(_transport_opts) self.transport = transport self.virtual_host = virtual_host if hosts is None: self.hosts = [] else: self.hosts = hosts if query is None: self.query = {} else: self.query = query def __hash__(self): return hash((tuple(self.hosts), self.transport, self.virtual_host)) def __eq__(self, other): return (self.transport == other.transport and self.virtual_host == other.virtual_host and self.hosts == other.hosts) def __ne__(self, other): return not self == other def __repr__(self): attrs = [] for a in ['transport', 'virtual_host', 'hosts']: v = getattr(self, a) if v: attrs.append((a, repr(v))) values = ', '.join(['%s=%s' % i for i in attrs]) return '' def __str__(self): netlocs = [] for host in self.hosts: username = host.username password = host.password hostname = host.hostname port = host.port # Starting place for the network location netloc = '' # Build the username and password portion of the transport URL if username is not None or password is not None: if username is not None: netloc += parse.quote(username, '') if password is not None: netloc += ':%s' % parse.quote(password, '') netloc += '@' # Build the network location portion of the transport URL if hostname: if ':' in hostname: netloc += '[%s]' % hostname else: netloc += hostname if port is not None: netloc += ':%d' % port netlocs.append(netloc) # Assemble the transport URL url = '%s://%s/' % (self.transport, ','.join(netlocs)) if self.virtual_host: url += parse.quote(self.virtual_host) if self.query: url += '?' + parse.urlencode(self.query, doseq=True) return url @classmethod def parse(cls, conf, url=None): """Parse a URL as defined by :py:class:`TransportURL` and return a TransportURL object. Assuming a URL takes the form of:: transport://user:pass@host:port[,userN:passN@hostN:portN]/virtual_host?query then parse the URL and return a TransportURL object. Netloc is parsed following the sequence bellow: * It is first split by ',' in order to support multiple hosts * All hosts should be specified with username/password or not at the same time. In case of lack of specification, username and password will be omitted:: user:pass@host1:port1,host2:port2 [ {"username": "user", "password": "pass", "host": "host1:port1"}, {"host": "host2:port2"} ] If the url is not provided conf.transport_url is parsed instead. :param conf: a ConfigOpts instance :type conf: oslo.config.cfg.ConfigOpts :param url: The URL to parse :type url: str :returns: A TransportURL """ if not url: conf.register_opts(_transport_opts) url = url or conf.transport_url if not isinstance(url, str): raise InvalidTransportURL(url, 'Wrong URL type') url = parse.urlparse(url) if not url.scheme: raise InvalidTransportURL(url.geturl(), 'No scheme specified') transport = url.scheme query = {} if url.query: for key, values in parse.parse_qs(url.query).items(): query[key] = ','.join(values) virtual_host = None if url.path.startswith('/'): virtual_host = parse.unquote(url.path[1:]) hosts_with_credentials = [] hosts_without_credentials = [] hosts = [] for host in url.netloc.split(','): if not host: continue hostname = host username = password = port = None if '@' in host: username, hostname = host.rsplit('@', 1) if ':' in username: username, password = username.split(':', 1) password = parse.unquote(password) username = parse.unquote(username) if not hostname: hostname = None elif hostname.startswith('['): # Find the closing ']' and extract the hostname host_end = hostname.find(']') if host_end < 0: # NOTE(Vek): Identical to what Python 2.7's # urlparse.urlparse() raises in this case raise ValueError('Invalid IPv6 URL') port_text = hostname[host_end:] hostname = hostname[1:host_end] # Now we need the port; this is compliant with how urlparse # parses the port data port = None if ':' in port_text: port = port_text.split(':', 1)[1] elif ':' in hostname: hostname, port = hostname.split(':', 1) if port == "": port = None if port is not None: port = int(port) if username is None or password is None: hosts_without_credentials.append(hostname) else: hosts_with_credentials.append(hostname) hosts.append(TransportHost(hostname=hostname, port=port, username=username, password=password)) if (len(hosts_with_credentials) > 0 and len(hosts_without_credentials) > 0): LOG.warning("All hosts must be set with username/password or " "not at the same time. Hosts with credentials " "are: %(hosts_with_credentials)s. Hosts without " "credentials are %(hosts_without_credentials)s.", {'hosts_with_credentials': hosts_with_credentials, 'hosts_without_credentials': hosts_without_credentials}) return cls(conf, transport, virtual_host, hosts, query)