Don't load DNS integration in l3_router_plugin

In this patchset we stop the l3_router_plugin from loading the DNS integration
extension. The DNS integration extension should only be configured by the
operator by adding 'dns' to the 'extension_driver' list in ml2_conf.ini

Change-Id: I1321d9821973fe918005a8c2f3dd751af9affe38
Closes-Bug: #1574694
(cherry picked from commit 56962922cc)

neutron/db/dns_db.py

@@ -28,8 +28,6 @@ from neutron.db import model_base
 from neutron.db import models_v2
 from neutron.extensions import dns
 from neutron.extensions import l3
-from neutron import manager
-from neutron.plugins.common import constants as service_constants
 from neutron.services.externaldns import driver
 
 LOG = logging.getLogger(__name__)
@@ -193,9 +191,8 @@ class DNSDbMixin(object):
     def _process_dns_floatingip_update_precommit(self, context,
                                                  floatingip_data):
         # expects to be called within a plugin's session
-        plugin = manager.NeutronManager.get_service_plugins().get(
-            service_constants.L3_ROUTER_NAT)
-        if not utils.is_extension_supported(plugin, dns.Dns.get_alias()):
+        if not utils.is_extension_supported(self._core_plugin,
+                                            dns.Dns.get_alias()):
             return
         if not self.dns_driver:
             return
@@ -251,9 +248,8 @@ class DNSDbMixin(object):
                 [floatingip_data['floating_ip_address']])
 
     def _process_dns_floatingip_delete(self, context, floatingip_data):
-        plugin = manager.NeutronManager.get_service_plugins().get(
-            service_constants.L3_ROUTER_NAT)
-        if not utils.is_extension_supported(plugin, dns.Dns.get_alias()):
+        if not utils.is_extension_supported(self._core_plugin,
+                                            dns.Dns.get_alias()):
             return
         dns_data_db = context.session.query(FloatingIPDNS).filter_by(
             floatingip_id=floatingip_data['id']).one_or_none()

neutron/db/l3_db.py

@@ -1119,7 +1119,8 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
             msg = _("Network %s does not contain any IPv4 subnet") % f_net_id
             raise n_exc.BadRequest(resource='floatingip', msg=msg)
 
-        dns_integration = utils.is_extension_supported(self, 'dns-integration')
+        dns_integration = utils.is_extension_supported(self._core_plugin,
+                                                       'dns-integration')
         with context.session.begin(subtransactions=True):
             # This external port is never exposed to the tenant.
             # it is used purely for internal system and admin use when
@@ -1186,7 +1187,8 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
 
     def _update_floatingip(self, context, id, floatingip):
         fip = floatingip['floatingip']
-        dns_integration = utils.is_extension_supported(self, 'dns-integration')
+        dns_integration = utils.is_extension_supported(self._core_plugin,
+                                                       'dns-integration')
         with context.session.begin(subtransactions=True):
             floatingip_db = self._get_floatingip(context, id)
             old_floatingip = self._make_floatingip_dict(floatingip_db)
@@ -1225,7 +1227,7 @@ class L3_NAT_dbonly_mixin(l3.RouterPluginBase,
     def _delete_floatingip(self, context, id):
         floatingip = self._get_floatingip(context, id)
         floatingip_dict = self._make_floatingip_dict(floatingip)
-        if utils.is_extension_supported(self, 'dns-integration'):
+        if utils.is_extension_supported(self._core_plugin, 'dns-integration'):
             self._process_dns_floatingip_delete(context, floatingip_dict)
         # Foreign key cascade will take care of the removal of the
         # floating IP record once the port is deleted. We can't start

neutron/services/l3_router/l3_router_plugin.py

@@ -54,8 +54,7 @@ class L3RouterPlugin(service_base.ServicePluginBase,
     """
     supported_extension_aliases = ["dvr", "router", "ext-gw-mode",
                                    "extraroute", "l3_agent_scheduler",
-                                   "l3-ha", "router_availability_zone",
-                                   "dns-integration"]
+                                   "l3-ha", "router_availability_zone"]
 
     @resource_registry.tracked_resources(router=l3_db.Router,
                                          floatingip=l3_db.FloatingIP)