Add initial support for handling notifications from other OpenStack services.

Change-Id: Icb8ed892f11bc195c83e8165776c11889fcf8f07

3 files changed, 187 insertions, 0 deletions

diff --git a/moniker/notification_handler/__init__.py b/moniker/notification_handler/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/moniker/notification_handler/__init__.py
diff --git a/moniker/notification_handler/base.py b/moniker/notification_handler/base.py
new file mode 100644
index 00000000..2c1ff859
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+++ b/moniker/notification_handler/base.py
@@ -0,0 +1,51 @@
+# Copyright 2012 Managed I.T.
+#
+# Author: Kiall Mac Innes <kiall@managedit.ie>
+#
+# 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 abc
+from moniker.openstack.common import log as logging
+
+
+LOG = logging.getLogger(__name__)
+
+
+class Handler(object):
+    """ Base class for notification handlers """
+
+    __metaclass__ = abc.ABCMeta
+
+    def __init__(self, central_service):
+        LOG.debug('Loaded handler: %s' % __name__)
+        self.central_service = central_service
+
+    @staticmethod
+    def register_opts(conf):
+        pass
+
+    @abc.abstractmethod
+    def get_exchange_topics(self):
+        """
+        Returns a tuple of (exchange, list(topics)) this handler wishes
+        to receive notifications from.
+        """
+
+    @abc.abstractmethod
+    def get_event_types(self):
+        """
+        Returns a list of event types this handler is capable of  processing
+        """
+
+    @abc.abstractmethod
+    def process_notification(self, event_type, payload):
+        """ Processes a given notification """
diff --git a/moniker/notification_handler/nova.py b/moniker/notification_handler/nova.py
new file mode 100644
index 00000000..2eaec5ac
--- /dev/null
+++ b/moniker/notification_handler/nova.py
@@ -0,0 +1,136 @@
+# Copyright 2012 Managed I.T.
+#
+# Author: Kiall Mac Innes <kiall@managedit.ie>
+#
+# 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.
+from moniker.openstack.common import cfg
+from moniker.openstack.common import log as logging
+from moniker.openstack.common.context import get_admin_context
+from moniker import exceptions
+from moniker.notification_handler.base import Handler
+
+LOG = logging.getLogger(__name__)
+
+
+class NovaHandler(Handler):
+    """ Hanlder for Nova's notifications """
+
+    def __init__(self, *args, **kwargs):
+        super(NovaHandler, self).__init__(*args, **kwargs)
+
+        self.fixed_ip_domain = cfg.CONF.nova_fixed_ip_domain
+
+        if not self.fixed_ip_domain:
+            msg = ('nova_fixed_ip_domain must be configured to use the nova '
+                   'handler')
+            raise exceptions.ConfigurationError(msg)
+
+    @staticmethod
+    def register_opts(conf):
+        conf.register_opts([
+            cfg.StrOpt('nova-fixed-ip-domain', default=None),
+            cfg.IntOpt('nova-control-exchange', default='nova'),
+            cfg.ListOpt('nova-notification-topics', default=['monitor'])
+        ])
+
+    def get_exchange_topics(self):
+        exchange = cfg.CONF.nova_control_exchange
+
+        topics = [topic + ".info"
+                  for topic in cfg.CONF.nova_notification_topics]
+
+        return (exchange, topics)
+
+    def get_event_types(self):
+        return [
+            'compute.instance.create.end',
+            'compute.instance.delete.start',
+            # 'compute.instance.rebuild.start',  # Needed?
+            # 'compute.instance.rebuild.end',    # Needed?
+            # 'compute.instance.exists',         # Needed?
+            # 'network.floating_ip.allocate',    # Needed?
+            # 'network.floating_ip.deallocate',  # Needed?
+            'network.floating_ip.associate',
+            'network.floating_ip.disassociate',
+        ]
+
+    def process_notification(self, event_type, payload):
+        LOG.debug('NovaHandler recieved notification - %s' % event_type)
+
+        if event_type == 'compute.instance.create.end':
+            return self.handle_instance_create(payload)
+
+        elif event_type == 'compute.instance.delete.start':
+            return self.handle_instance_delete(payload)
+
+        elif event_type == 'network.floating_ip.associate':
+            return self.handle_floating_ip_associate(payload)
+
+        elif event_type == 'network.floating_ip.disassociate':
+            return self.handle_floating_ip_disassociate(payload)
+
+        else:
+            raise ValueError('NovaHandler recieved an invalid event type')
+
+    def handle_instance_create(self, payload):
+        context = get_admin_context()
+
+        # Fetch the FixedIP Domain
+        fixed_ip_domain = self.central_service.get_domain(context,
+                                                          self.fixed_ip_domain)
+
+        # For each fixed ip, create an associated record.
+        for fixed_ip in payload['fixed_ips']:
+            record_name = '%(instance_id)s.%(tenant_id)s.%(domain)s' % dict(
+                instance_id=payload['instance_id'],
+                tenant_id=payload['tenant_id'],
+                domain=fixed_ip_domain['name'])
+
+            record_values = {
+                'type': 'A' if fixed_ip['version'] == 4 else 'AAAA',
+                'name': record_name,
+                'data': fixed_ip['address'],
+
+                'managed_resource': True,
+                'managed_resource_type': u'instance',
+                'managed_resource_id': payload['instance_id'],
+            }
+
+            self.central_service.create_record(context, self.fixed_ip_domain,
+                                               record_values)
+
+    def handle_instance_delete(self, payload):
+        context = get_admin_context()
+
+        # Fetch the instances managed records
+        criterion = {
+            'managed_resource': True,
+            'managed_resource_type': u'instance',
+            'managed_resource_id': payload['instance_id']
+        }
+
+        records = self.central_service.get_records(context,
+                                                   self.fixed_ip_domain,
+                                                   criterion)
+        # Delete the matching records
+        for record in records:
+            LOG.debug('Deleting record %s' % record['id'])
+
+            self.central_service.delete_record(context, self.fixed_ip_domain,
+                                               record['id'])
+
+    def handle_floating_ip_associate(self, payload):
+        pass
+
+    def handle_floating_ip_disassociate(self, payload):
+        pass