NSX|V3 Fix dhcp-relay validation

When DHCP relay is configured, a compute port cannot be created
without a router attached to its subnet.
Due to an error in the validation, all compute ports creation
was blocked.

Change-Id: I6016d7015376c280a36b716f3e478d488988b237

vmware_nsx/plugins/common_v3/plugin.py

@@ -552,7 +552,7 @@ class NsxPluginV3Base(agentschedulers_db.AZDhcpAgentSchedulerDbMixin,
                           for fixed_ip in port_data['fixed_ips'])
 
         # check only dhcp enabled subnets
-        return (self.get_subnet(context.elevated(), subnet_id)
+        return (self._get_subnet(context.elevated(), subnet_id)
                 for subnet_id in subnet_ids)
 
     def _validate_create_port(self, context, port_data):

vmware_nsx/plugins/nsx_v3/plugin.py

@@ -1493,11 +1493,10 @@ class NsxV3Plugin(nsx_plugin_common.NsxPluginV3Base,
                         'network_id': [original_port['network_id']]}
         interfaces = self.get_ports(context.elevated(), filters=port_filters)
         for interface in interfaces:
-            for subnet in subnets:
-                for fixed_ip in interface['fixed_ips']:
-                    if fixed_ip['subnet_id'] in subnet_ids:
-                        # Router exists - validation passed
-                        return
+            for fixed_ip in interface['fixed_ips']:
+                if fixed_ip['subnet_id'] in subnet_ids:
+                    # Router exists - validation passed
+                    return
 
         err_msg = _("Neutron is configured with DHCP_Relay but no router "
                     "connected to the subnet")

vmware_nsx/tests/unit/nsx_v3/test_plugin.py

@@ -15,6 +15,7 @@
 
 import mock
 import netaddr
+from neutron.db import l3_db
 from neutron.db import models_v2
 from neutron.db import securitygroups_db as sg_db
 from neutron.extensions import address_scope
@@ -1736,6 +1737,40 @@ class TestPortsV2(common_v3.NsxV3SubnetMixin,
                               self.plugin.create_port,
                               self.ctx, data)
 
+    def test_create_compute_port_with_relay_and_router(self):
+        self._enable_dhcp_relay()
+        with self.network() as network, \
+            self.subnet(network=network, enable_dhcp=True) as s1,\
+            mock.patch.object(self.plugin, '_get_router',
+                              return_value={'name': 'dummy'}):
+            # first create a router interface to simulate a router
+            data = {'port': {
+                        'network_id': network['network']['id'],
+                        'tenant_id': self._tenant_id,
+                        'name': 'port',
+                        'admin_state_up': True,
+                        'device_id': 'dummy',
+                        'device_owner': l3_db.DEVICE_OWNER_ROUTER_INTF,
+                        'fixed_ips': [{'subnet_id': s1['subnet']['id']}],
+                        'mac_address': '00:00:00:00:00:02'}
+                    }
+            port1 = self.plugin.create_port(self.ctx, data)
+            self.assertIn('id', port1)
+            # Now create a compute port
+            device_owner = constants.DEVICE_OWNER_COMPUTE_PREFIX + 'X'
+            data = {'port': {
+                        'network_id': network['network']['id'],
+                        'tenant_id': self._tenant_id,
+                        'name': 'port',
+                        'admin_state_up': True,
+                        'device_id': 'fake_device',
+                        'device_owner': device_owner,
+                        'fixed_ips': [{'subnet_id': s1['subnet']['id']}],
+                        'mac_address': '00:00:00:00:00:01'}
+                    }
+            port2 = self.plugin.create_port(self.ctx, data)
+            self.assertIn('id', port2)
+
     def _test_create_direct_network(self, vlan_id=0):
         net_type = vlan_id and 'vlan' or 'flat'
         name = 'direct_net'