Merge "NSX|V3: update DHCP static bindings when DHCP is enabled"

vmware_nsx/db/db.py

@@ -191,6 +191,11 @@ def delete_neutron_nsx_dhcp_binding(session, port_id, binding_id):
         port_id=port_id, nsx_binding_id=binding_id).delete()
 
 
+def delete_neutron_nsx_dhcp_bindings_by_service_id(session, service_id):
+    return session.query(nsx_models.NeutronNsxDhcpBinding).filter_by(
+        nsx_service_id=service_id).delete()
+
+
 def get_nsx_switch_ids(session, neutron_id):
     # This function returns a list of NSX switch identifiers because of
     # the possibility of chained logical switches

vmware_nsx/plugins/nsx_v3/plugin.py

@@ -931,6 +931,10 @@ class NsxV3Plugin(agentschedulers_db.AZDhcpAgentSchedulerDbMixin,
         # entries are still there.
         self._disable_native_dhcp(context, network['id'])
 
+        # Get existing ports on subnet.
+        existing_ports = super(NsxV3Plugin, self).get_ports(
+            context, filters={'network_id': [network['id']],
+                              'fixed_ips': {'subnet_id': [subnet['id']]}})
         port_data = {
             "name": "",
             "admin_state_up": True,
@@ -992,6 +996,14 @@ class NsxV3Plugin(agentschedulers_db.AZDhcpAgentSchedulerDbMixin,
                 self._dhcp_server.delete(dhcp_server['id'])
                 self._cleanup_port(context, neutron_port['id'], nsx_port['id'])
 
+        # Configure existing ports to work with the new DHCP server
+        try:
+            for port_data in existing_ports:
+                self._add_dhcp_binding(context, port_data)
+        except Exception:
+            LOG.error(_LE('Unable to create DHCP bindings for existing ports '
+                          'on subnet %s'), subnet['id'])
+
     def _disable_native_dhcp(self, context, network_id):
         # Disable native DHCP service on the backend for this network.
         # First delete the DHCP port in this network. Then delete the
@@ -1030,6 +1042,9 @@ class NsxV3Plugin(agentschedulers_db.AZDhcpAgentSchedulerDbMixin,
             # Delete neutron_id -> dhcp_service_id mapping from the DB.
             nsx_db.delete_neutron_nsx_service_binding(
                 context.session, network_id, nsxlib_consts.SERVICE_DHCP)
+            # Delete all DHCP bindings under this DHCP server from the DB.
+            nsx_db.delete_neutron_nsx_dhcp_bindings_by_service_id(
+                context.session, dhcp_service['nsx_service_id'])
         except db_exc.DBError:
             with excutils.save_and_reraise_exception():
                 LOG.error(_LE("Unable to delete DHCP server mapping for "

vmware_nsx/tests/unit/nsx_v3/test_dhcp_metadata.py

@@ -380,6 +380,40 @@ class NsxNativeDhcpTestCase(test_plugin.NsxV3PluginTestCaseMixin):
                         port['port']['mac_address'], ip, hostname,
                         cfg.CONF.nsx_v3.dhcp_lease_time, options)
 
+    def test_dhcp_binding_with_disable_enable_dhcp(self):
+        # Test if DHCP binding is preserved after DHCP is disabled and
+        # re-enabled on a subnet.
+        with self.subnet(enable_dhcp=True) as subnet:
+            device_owner = constants.DEVICE_OWNER_COMPUTE_PREFIX + 'None'
+            device_id = uuidutils.generate_uuid()
+            with self.port(subnet=subnet, device_owner=device_owner,
+                           device_id=device_id) as port:
+                ip = port['port']['fixed_ips'][0]['ip_address']
+                dhcp_bindings = nsx_db.get_nsx_dhcp_bindings(
+                    context.get_admin_context().session, port['port']['id'])
+                dhcp_service = dhcp_bindings[0]['nsx_service_id']
+                self.assertEqual(1, len(dhcp_bindings))
+                self.assertEqual(ip, dhcp_bindings[0]['ip_address'])
+                # Disable DHCP on subnet.
+                data = {'subnet': {'enable_dhcp': False}}
+                self.plugin.update_subnet(context.get_admin_context(),
+                                          subnet['subnet']['id'], data)
+                dhcp_bindings = nsx_db.get_nsx_dhcp_bindings(
+                    context.get_admin_context().session, port['port']['id'])
+                self.assertEqual([], dhcp_bindings)
+                # Re-enable DHCP on subnet.
+                data = {'subnet': {'enable_dhcp': True}}
+                self.plugin.update_subnet(context.get_admin_context(),
+                                          subnet['subnet']['id'], data)
+                dhcp_bindings = nsx_db.get_nsx_dhcp_bindings(
+                    context.get_admin_context().session, port['port']['id'])
+                self.assertEqual(1, len(dhcp_bindings))
+                self.assertEqual(ip, dhcp_bindings[0]['ip_address'])
+                # The DHCP service ID should be different because a new
+                # logical DHCP server is created for re-enabling DHCP.
+                self.assertNotEqual(dhcp_service,
+                                    dhcp_bindings[0]['nsx_service_id'])
+
     def test_dhcp_binding_with_delete_port(self):
         # Test if DHCP binding is removed when the associated compute port
         # is deleted.