Merge "Fix DHCP Port Creation on Service Subnets"

neutron/db/ipam_backend_mixin.py

@@ -595,12 +595,18 @@ class IpamBackendMixin(db_base_plugin_common.DbBasePluginCommon):
 
     def _query_filter_service_subnets(self, query, service_type):
         # TODO(korzen) use SubnetServiceType OVO here
+        Subnet = models_v2.Subnet
         ServiceType = sst_model.SubnetServiceType
         query = query.add_entity(ServiceType)
         query = query.outerjoin(ServiceType)
-        query = query.filter(or_(ServiceType.service_type.is_(None),
-                                 ServiceType.service_type == service_type))
-        return query.from_self(models_v2.Subnet)
+        query = query.filter(or_(
+            ServiceType.service_type.is_(None),
+            ServiceType.service_type == service_type,
+            # Allow DHCP ports to be created on subnets of any
+            # service type when DHCP is enabled on the subnet.
+            and_(Subnet.enable_dhcp.is_(True),
+                 service_type == const.DEVICE_OWNER_DHCP)))
+        return query.from_self(Subnet)
 
     @staticmethod
     def _query_filter_by_segment_host_mapping(query, host):

neutron/tests/unit/extensions/test_subnet_service_types.py

@@ -55,7 +55,7 @@ class SubnetServiceTypesExtensionTestCase(
               self).setUp(plugin=plugin, ext_mgr=ext_mgr)
 
     def _create_service_subnet(self, service_types=None, cidr=None,
-                               network=None):
+                               network=None, enable_dhcp=False):
         if not network:
             with self.network() as network:
                 pass
@@ -65,7 +65,8 @@ class SubnetServiceTypesExtensionTestCase(
         args = {'net_id': network['id'],
                 'tenant_id': network['tenant_id'],
                 'cidr': cidr,
-                'ip_version': self.IP_VERSION}
+                'ip_version': self.IP_VERSION,
+                'enable_dhcp': enable_dhcp}
         if service_types:
             args['service_types'] = service_types
         return self._create_subnet(self.fmt, **args)
@@ -274,6 +275,24 @@ class SubnetServiceTypesExtensionTestCase(
     def test_create_port_exhausted_subnet_no_fallback(self):
         self.test_create_port_exhausted_subnet(fallback=False)
 
+    def test_create_dhcp_port_compute_subnet(self, enable_dhcp=True):
+        with self.network() as network:
+            pass
+        res = self._create_service_subnet(['compute:nova'],
+                                          network=network,
+                                          enable_dhcp=enable_dhcp)
+        subnet = self.deserialize('json', res)['subnet']
+        network = network['network']
+        port = self._create_port(self.fmt,
+                                 net_id=network['id'],
+                                 tenant_id=network['tenant_id'],
+                                 fixed_ips=[{'subnet_id': subnet['id']}],
+                                 device_owner='network:dhcp')
+        self._assert_port_res(port, 'network:dhcp', subnet, enable_dhcp)
+
+    def test_create_dhcp_port_compute_subnet_no_dhcp(self):
+        self.test_create_dhcp_port_compute_subnet(enable_dhcp=False)
+
 
 class SubnetServiceTypesExtensionTestCasev6(
         SubnetServiceTypesExtensionTestCase):

releasenotes/notes/dhcp-for-service-subnets-06f03d902f2fb738.yaml

@@ -0,0 +1,10 @@
+---
+fixes:
+  - A special case has been added to allow the creation of DHCP ports
+    on Service Subnets that do not have the service type "network:dhcp",
+    provided that the subnet has 'enable_dhcp' set to 'True'.
+    This fixes the recurring error seen when neutron attempts to
+    automatically create a DHCP port on a dhcp-enabled subnet after the
+    subnet is created. See bug report
+    `1636963 <https://bugs.launchpad.net/neutron/+bug/1636963>`_ for
+    more details.