Recycle IPs used by 'gateway' ports

Bug 1182602

Previous code simply removed IP allocation for these ports which
should never have an IP. This patch triggers IP recycling so the
IP addresses can be reused by other ports.

Change-Id: I594e02d5bbc78b219eab07e595cde713d6450ffe

quantum/plugins/nicira/nicira_networkgw_db.py

@@ -26,7 +26,6 @@
 from quantum.api.v2 import attributes
 from quantum.api.v2 import base
 from quantum.common import exceptions
-from quantum.db import db_base_plugin_v2
 from quantum.db import model_base
 from quantum.db import models_v2
 from quantum.openstack.common import log as logging
@@ -267,7 +266,7 @@ def connect_network(self, context, network_gateway_id,
                                                   network_mapping_info):
                 raise GatewayConnectionInUse(mapping=network_mapping_info,
                                              gateway_id=network_gateway_id)
-            # TODO(salvatore-orlando): This will give the port a fixed_ip,
+            # TODO(salvatore-orlando): Creating a port will give it an IP,
             # but we actually do not need any. Instead of wasting an IP we
             # should have a way to say a port shall not be associated with
             # any subnet
@@ -313,12 +312,11 @@ def connect_network(self, context, network_gateway_id,
             gw_db.network_connections.append(
                 NetworkConnection(**network_mapping_info))
             port_id = port['id']
-            # now deallocate the ip from the port
+            # now deallocate and recycle ip from the port
             for fixed_ip in port.get('fixed_ips', []):
-                db_base_plugin_v2.QuantumDbPluginV2._delete_ip_allocation(
-                    context, network_id,
-                    fixed_ip['subnet_id'],
-                    fixed_ip['ip_address'])
+                self._recycle_ip(context, network_id,
+                                 fixed_ip['subnet_id'],
+                                 fixed_ip['ip_address'])
             LOG.debug(_("Ensured no Ip addresses are configured on port %s"),
                       port_id)
             return {'connection_info':

quantum/tests/unit/nicira/test_networkgw.py

@@ -462,6 +462,35 @@ def test_connect_unspecified_network_returns_400(self):
                                      'vlan', 555,
                                      expected_status=exc.HTTPBadRequest.code)
 
+    def test_connect_network_does_not_waste_ips(self):
+        # Ensure address is immediately recycled
+        cfg.CONF.set_override('dhcp_lease_duration', -1)
+        with self._network_gateway() as gw:
+            with self.network() as net:
+                with self.subnet(network=net) as sub:
+                    with self.port(subnet=sub) as port_1:
+                        expected_ips = port_1['port']['fixed_ips']
+                    # port_1 has now been deleted
+                    body = self._gateway_action('connect',
+                                                gw[self.resource]['id'],
+                                                net['network']['id'],
+                                                'flat')
+                    gw_port_id = body['connection_info']['port_id']
+                    gw_port_body = self._show('ports', gw_port_id)
+                    self.assertEqual(gw[self.resource]['id'],
+                                     gw_port_body['port']['device_id'])
+                    self.assertEqual([], gw_port_body['port']['fixed_ips'])
+                    # Verify a new port gets same address as port_1
+                    # This will confirm the gateway port did not waste an ip
+                    with self.port(subnet=sub) as port_2:
+                        self.assertEqual(expected_ips,
+                                         port_2['port']['fixed_ips'])
+                    # Clean up - otherwise delete will fail
+                    self._gateway_action('disconnect',
+                                         gw[self.resource]['id'],
+                                         net['network']['id'],
+                                         'flat')
+
     def test_disconnect_network_ambiguous_returns_409(self):
         with self._network_gateway() as gw:
             with self.network() as net_1: