Enable notification messaging pools

Use notification pools by default and use the same notification
topic as ceilometer, separate notification topic is no need to add.

Change-Id: Ieef1ece78e6e8d20abfeea9546e1a9170b7eeb70

bilean/common/consts.py

@@ -20,13 +20,11 @@ MAX_RESOURCE_NUM = 1000
 RPC_ATTRS = (
     ENGINE_TOPIC,
     SCHEDULER_TOPIC,
-    NOTIFICATION_TOPICS,
     ENGINE_DISPATCHER_TOPIC,
     RPC_API_VERSION,
 ) = (
     'bilean-engine',
     'bilean-scheduler',
-    'billing_notifications',
     'bilean_engine_dispatcher',
     '1.0',
 )

bilean/engine/flows/flow.py

@@ -24,7 +24,7 @@ from bilean.common import exception
 from bilean.common.i18n import _LE
 from bilean.engine import policy as policy_mod
 from bilean.engine import user as user_mod
-from bilean.plugin import base as plugin_base
+from bilean.plugins import base as plugin_base
 from bilean import scheduler as bilean_scheduler
 
 LOG = logging.getLogger(__name__)

bilean/notification/notification.py

@@ -11,37 +11,75 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from oslo_config import cfg
 from oslo_log import log as logging
 import oslo_messaging
 from oslo_service import service
 
-from bilean.common import consts
-from bilean.common.i18n import _
+from bilean.common.i18n import _LE
 from bilean.common import messaging as bilean_messaging
+from bilean.engine import environment
 from bilean.notification import endpoint
 
 LOG = logging.getLogger(__name__)
 
+listener_opts = [
+    cfg.IntOpt('workers',
+               default=1,
+               min=1,
+               help='Number of workers for notification service. A single '
+               'notification agent is enabled by default.'),
+    cfg.StrOpt('notifications_pool',
+               default='bilean-listener',
+               help='Use an oslo.messaging pool, which can be an alternative '
+               'to multiple topics. ')
+]
+
+CONF = cfg.CONF
+CONF.register_opts(listener_opts, group="listener")
+
 
 class NotificationService(service.Service):
 
     def __init__(self, *args, **kwargs):
         super(NotificationService, self).__init__(*args, **kwargs)
-        self.targets, self.listeners = [], []
-        self.transport = None
-        self.group_id = None
-        self.endpoints = [endpoint.EventsNotificationEndpoint()]
+        self.listeners = []
+        self.topics_exchanges_set = self.topics_and_exchanges()
+
+    def topics_and_exchanges(self):
+        topics_exchanges = set()
+        plugins = environment.global_env().get_plugins()
+        for plugin in plugins:
+            try:
+                topic_exchanges = plugin.get_notification_topics_exchanges()
+                for plugin_topic in topic_exchanges:
+                    if isinstance(plugin_topic, basestring):
+                        raise Exception(
+                            _LE("Plugin %s should return a list of topic "
+                                "exchange pairs") % plugin.__class__.__name__)
+                    topics_exchanges.add(plugin_topic)
+            except Exception as e:
+                LOG.error(_LE("Failed to retrieve notification topic(s) "
+                              "and exchanges from bilean plugin "
+                              "%(ext)s: %(e)s") %
+                          {'ext': plugin.__name__, 'e': e})
+
+        return topics_exchanges
 
     def start(self):
         super(NotificationService, self).start()
-        self.transport = bilean_messaging.get_transport()
-        self.targets.append(
-            oslo_messaging.Target(topic=consts.NOTIFICATION_TOPICS))
-        listener = bilean_messaging.get_notification_listener(
-            self.transport, self.targets, self.endpoints)
+        transport = bilean_messaging.get_transport()
+        targets = [
+            oslo_messaging.Target(topic=tp, exchange=eg)
+            for tp, eg in self.topics_exchanges_set
+        ]
+        endpoints = [endpoint.EventsNotificationEndpoint()]
+        listener = oslo_messaging.get_notification_listener(
+            transport,
+            targets,
+            endpoints,
+            pool=CONF.listener.notifications_pool)
 
-        LOG.info(_("Starting listener on topic: %s"),
-                 consts.NOTIFICATION_TOPICS)
         listener.start()
         self.listeners.append(listener)
 

bilean/plugins/os/nova/server.py

@@ -128,4 +128,4 @@ class ServerPlugin(base.Plugin):
 
     RuleClass = ServerRule
     ResourceClass = ServerResource
-    notification_exchanges = ['nova', 'neutron']
+    notification_exchanges = ['nova']

devstack/README.rst

@@ -22,8 +22,21 @@ Enabling Bilean in DevStack
 
    Bilean service is driven using a plugin mechanism for integrating to other
    services. Each integrated service may require additional configuration
-   settings. For example, typically, you will need to add the
-   ``billing_notifications`` notification topic to each service's configuration.
+   settings. Typically, you will need to set the notifications driver in each
+   service's configuration.
+
+   For example, to enable nova service, edit `/etc/nova/nvoa.conf` and add
+   following configuration::
+
+       [oslo_messaging_notifications]
+       driver = messaging
+
+   Or add following configurations to post config section in `local.conf` to
+   make devstack automaticlly configure the settings above::
+
+       [[post-config|$NOVA_CONF]]
+       [oslo_messaging_notifications]
+       driver = messaging
 
 4. Then run devstack normally.
 

doc/source/install.rst

@@ -46,8 +46,21 @@ following detailed instructions.
 
    Bilean service is driven using a plugin mechanism for integrating to other
    services. Each integrated service may require additional configuration
-   settings. For example, typically, you will need to add the
-   ``billing_notifications`` notification topic to each service's configuration.
+   settings. Typically, you will need to set the notifications driver in each
+   service's configuration.
+
+   For example, to enable nova service, edit `/etc/nova/nvoa.conf` and add
+   following configuration::
+
+       [oslo_messaging_notifications]
+       driver = messaging
+
+   Or add following configurations to post config section in `local.conf` to
+   make devstack automaticlly configure the settings above::
+
+       [[post-config|$NOVA_CONF]]
+       [oslo_messaging_notifications]
+       driver = messaging
 
 4. Then run devstack normally.