Merge "DHCP: release DHCP port if not enough memory"

neutron/agent/linux/dhcp.py

@@ -24,6 +24,7 @@ import netaddr
 from oslo_config import cfg
 from oslo_log import log as logging
 import oslo_messaging
+from oslo_utils import excutils
 from oslo_utils import uuidutils
 import six
 
@@ -1202,11 +1203,19 @@ class DeviceManager(object):
                                          namespace=network.namespace):
             LOG.debug('Reusing existing device: %s.', interface_name)
         else:
-            self.driver.plug(network.id,
-                             port.id,
-                             interface_name,
-                             port.mac_address,
-                             namespace=network.namespace)
+            try:
+                self.driver.plug(network.id,
+                                 port.id,
+                                 interface_name,
+                                 port.mac_address,
+                                 namespace=network.namespace)
+            except Exception:
+                with excutils.save_and_reraise_exception():
+                    LOG.exception(_LE('Unable to plug DHCP port for '
+                                      'network %s. Releasing port.'),
+                                  network.id)
+                    self.plugin.release_dhcp_port(network.id, port.device_id)
+
             self.fill_dhcp_udp_checksums(namespace=network.namespace)
         ip_cidrs = []
         for fixed_ip in port.fixed_ips:

neutron/tests/unit/agent/dhcp/test_agent.py

@@ -1336,6 +1336,21 @@ class TestDeviceManager(base.BaseTestCase):
                           'device_id': mock.ANY}})])
         self.assertIn(fake_dhcp_port, net.ports)
 
+    def test_setup_plug_exception(self):
+        plugin = mock.Mock()
+        plugin.create_dhcp_port.return_value = fake_dhcp_port
+        self.ensure_device_is_ready.return_value = False
+        self.mock_driver.get_device_name.return_value = 'tap12345678-12'
+        dh = dhcp.DeviceManager(cfg.CONF, plugin)
+        dh._set_default_route = mock.Mock()
+        dh._cleanup_stale_devices = mock.Mock()
+        dh.driver = mock.Mock()
+        dh.driver.plug.side_effect = OSError()
+        net = copy.deepcopy(fake_network)
+        self.assertRaises(OSError, dh.setup, net)
+        plugin.release_dhcp_port.assert_called_once_with(
+            net.id, mock.ANY)
+
     def test_setup_ipv6(self):
         self._test_setup_helper(True, net=fake_network_ipv6,
                                 port=fake_ipv6_port)