Remove EXTERNAL_NETWORK callbacks

external networks are not really independent resources that
have their own lifecycles independent from networks. The only
use cases for this callback can be achieved with just regular
NETWORK callbacks.

The only users of this event have been adjusted to use NETWORK
callbacks (according to codesearch.openstack.org).

Closes-Bug: #1678041
Change-Id: Ie8249ddc3de643bfcb5c97480f30dc3500699256

neutron/callbacks/resources.py

@@ -12,7 +12,6 @@
 
 # String literals representing core resources.
 AGENT = 'agent'
-EXTERNAL_NETWORK = 'external_network'
 FLOATING_IP = 'floatingip'
 NETWORK = 'network'
 NETWORKS = 'networks'

neutron/db/external_net_db.py

@@ -22,7 +22,6 @@ from sqlalchemy.sql import expression as expr
 from neutron._i18n import _
 from neutron.api.v2 import attributes
 from neutron.callbacks import events
-from neutron.callbacks import exceptions as c_exc
 from neutron.callbacks import registry
 from neutron.callbacks import resources
 from neutron.db import _model_query as model_query
@@ -103,26 +102,9 @@ class External_net_db_mixin(object):
             context.session.add(rbac_db.NetworkRBAC(
                   object_id=net_data['id'], action='access_as_external',
                   target_tenant='*', tenant_id=net_data['tenant_id']))
-            try:
-                registry.notify(
-                    resources.EXTERNAL_NETWORK, events.PRECOMMIT_CREATE,
-                    self, context=context,
-                    request=req_data, network=net_data)
-            except c_exc.CallbackFailure as e:
-                # raise the underlying exception
-                raise e.errors[0].error
         net_data[external_net.EXTERNAL] = external
 
     def _process_l3_update(self, context, net_data, req_data, allow_all=True):
-        try:
-            registry.notify(
-                resources.EXTERNAL_NETWORK, events.BEFORE_UPDATE,
-                self, context=context,
-                request=req_data, network=net_data)
-        except c_exc.CallbackFailure as e:
-            # raise the underlying exception
-            raise e.errors[0].error
-
         new_value = req_data.get(external_net.EXTERNAL)
         net_id = net_data['id']
         if not validators.is_attr_set(new_value):