bug 899767: fix vif-plugging with live migration

Expose vif_unplug method in virt layer, as the compute manager has to
explicitly call it on during live migration, so that network devices are
torn down even if the disk image is not.

Change-Id: Iae88c72f4fd2c7c097c23ef9e5f8fd392052f73e

nova/compute/manager.py

@@ -1735,6 +1735,12 @@ def post_live_migration(self, ctxt, instance_ref,
         # must be deleted for preparing next block migration
         if block_migration:
             self.driver.destroy(instance_ref, network_info)
+        else:
+            # self.driver.destroy() usually performs  vif unplugging
+            # but we must do it explicitly here when block_migration
+            # is false, as the network devices at the source must be
+            # torn down
+            self.driver.unplug_vifs(instance_ref, network_info)
 
         LOG.info(_('Migrating %(i_name)s to %(dest)s finished successfully.')
                  % locals())

nova/tests/test_compute.py

@@ -1022,6 +1022,8 @@ def test_post_live_migration_working_correctly(self):
         rpc.call(c, db.queue_get_for(c, FLAGS.compute_topic, dest),
             {"method": "post_live_migration_at_destination",
              "args": {'instance_id': i_ref['id'], 'block_migration': False}})
+        self.mox.StubOutWithMock(self.compute.driver, 'unplug_vifs')
+        self.compute.driver.unplug_vifs(i_ref, [])
 
         # start test
         self.mox.ReplayAll()

nova/virt/driver.py

@@ -516,10 +516,14 @@ def set_host_enabled(self, host, enabled):
         raise NotImplementedError()
 
     def plug_vifs(self, instance, network_info):
-        """Plugs in VIFs to networks."""
+        """Plug VIFs into networks."""
         # TODO(Vek): Need to pass context in for access to auth_token
         raise NotImplementedError()
 
+    def unplug_vifs(self, instance, network_info):
+        """Unplug VIFs from networks."""
+        raise NotImplementedError()
+
     def update_host_status(self):
         """Refresh host stats"""
         raise NotImplementedError()

nova/virt/fake.py

@@ -94,7 +94,11 @@ def list_instances_detail(self):
         return info_list
 
     def plug_vifs(self, instance, network_info):
-        """Plugin VIFs into networks."""
+        """Plug VIFs into networks."""
+        pass
+
+    def unplug_vifs(self, instance, network_info):
+        """Unplug VIFs from networks."""
         pass
 
     def spawn(self, context, instance, image_meta,

nova/virt/hyperv.py

@@ -516,3 +516,11 @@ def host_power_action(self, host, action):
     def set_host_enabled(self, host, enabled):
         """Sets the specified host's ability to accept new instances."""
         pass
+
+    def plug_vifs(self, instance, network_info):
+        """Plug VIFs into networks."""
+        pass
+
+    def unplug_vifs(self, instance, network_info):
+        """Unplug VIFs from networks."""
+        pass

nova/virt/libvirt/connection.py

@@ -290,10 +290,15 @@ def list_instances_detail(self):
         return infos
 
     def plug_vifs(self, instance, network_info):
-        """Plugin VIFs into networks."""
+        """Plug VIFs into networks."""
         for (network, mapping) in network_info:
             self.vif_driver.plug(instance, network, mapping)
 
+    def unplug_vifs(self, instance, network_info):
+        """Unplug VIFs from networks."""
+        for (network, mapping) in network_info:
+            self.vif_driver.unplug(instance, network, mapping)
+
     def destroy(self, instance, network_info, block_device_info=None,
                 cleanup=True):
         instance_name = instance['name']
@@ -350,8 +355,7 @@ def destroy(self, instance, network_info, block_device_info=None,
                             locals())
                 raise
 
-        for (network, mapping) in network_info:
-            self.vif_driver.unplug(instance, network, mapping)
+        self.unplug_vifs(instance, network_info)
 
         def _wait_for_destroy():
             """Called at an interval until the VM is gone."""
@@ -545,6 +549,7 @@ def reboot(self, instance, network_info, reboot_type=None, xml=None):
         # better because we cannot ensure flushing dirty buffers
         # in the guest OS. But, in case of KVM, shutdown() does not work...
         self.destroy(instance, network_info, cleanup=False)
+        self.unplug_vifs(instance, network_info)
         self.plug_vifs(instance, network_info)
         self.firewall_driver.setup_basic_filtering(instance, network_info)
         self.firewall_driver.prepare_instance_filter(instance, network_info)

nova/virt/vmwareapi_conn.py

@@ -201,9 +201,13 @@ def set_host_enabled(self, host, enabled):
         pass
 
     def plug_vifs(self, instance, network_info):
-        """Plugs in VIFs to networks."""
+        """Plug VIFs into networks."""
         self._vmops.plug_vifs(instance, network_info)
 
+    def unplug_vifs(self, instance, network_info):
+        """Unplug VIFs from networks."""
+        self._vmops.unplug_vifs(instance, network_info)
+
 
 class VMWareAPISession(object):
     """

nova/virt/xenapi/vmops.py

@@ -1139,9 +1139,7 @@ def _destroy(self, instance, vm_ref, network_info=None, shutdown=True,
             self._destroy_kernel_ramdisk(instance, vm_ref)
         self._destroy_vm(instance, vm_ref)
 
-        if network_info:
-            for (network, mapping) in network_info:
-                self.vif_driver.unplug(instance, network, mapping)
+        self.unplug_vifs(instance, network_info)
 
     def pause(self, instance):
         """Pause VM instance."""
@@ -1459,6 +1457,11 @@ def plug_vifs(self, instance, network_info):
         for (network, mapping) in network_info:
             self.vif_driver.plug(self._session, instance, network, mapping)
 
+    def unplug_vifs(self, instance, network_info):
+        if network_info:
+            for (network, mapping) in network_info:
+                self.vif_driver.unplug(instance, network, mapping)
+
     def reset_network(self, instance, vm_ref=None):
         """Creates uuid arg to pass to make_agent_call and calls it."""
         if not vm_ref:

nova/virt/xenapi_conn.py

@@ -297,8 +297,13 @@ def inject_network_info(self, instance, network_info):
         self._vmops.inject_network_info(instance, network_info)
 
     def plug_vifs(self, instance_ref, network_info):
+        """Plug VIFs into networks."""
         self._vmops.plug_vifs(instance_ref, network_info)
 
+    def unplug_vifs(self, instance_ref, network_info):
+        """Unplug VIFs from networks."""
+        self._vmops.unplug_vifs(instance_ref, network_info)
+
     def get_info(self, instance_name):
         """Return data about VM instance"""
         return self._vmops.get_info(instance_name)