Ignore plug_vifs on the ironic driver

When the nova-compute service starts, by default it attempts to
startup instance configuration states for aspects such as networking.
This is fine in most cases, and makes a lot of sense if the
nova-compute service is just managing virtual machines on a hypervisor.

This is done, one instance at a time.

However, when the compute driver is ironic, the networking is managed
as part of the physical machine lifecycle potentially all the way into
committed switch configurations. As such, there is no need to attempt
to call ``plug_vifs`` on every single instance managed by the
nova-compute process which is backed by Ironic.

Additionally, using ironic tends to manage far more physical machines
per nova-compute service instance then when when operating co-installed
with a hypervisor. Often this means a cluster of a thousand machines,
with three controllers, will see thousands of un-needed API calls upon
service start, which elongates the entire process and negatively
impacts operations.

In essence, nova.virt.ironic's plug_vifs call now does nothing,
and merely issues a debug LOG entry when called.

Closes-Bug: #1777608
Change-Id: Iba87cef50238c5b02ab313f2311b826081d5b4ab
(cherry picked from commit 7f81cf28bf21ad2afa98accfde3087c83b8e269b)

1 files changed, 20 insertions, 13 deletions

diff --git a/nova/tests/unit/virt/ironic/test_driver.py b/nova/tests/unit/virt/ironic/test_driver.py
index 7b94a44412..7b377b21c2 100644
--- a/nova/tests/unit/virt/ironic/test_driver.py
+++ b/nova/tests/unit/virt/ironic/test_driver.py
@@ -2016,17 +2016,12 @@ class IronicDriverTestCase(test.NoDBTestCase):
     @mock.patch.object(ironic_driver.IronicDriver, '_plug_vifs')
     def test_plug_vifs(self, mock__plug_vifs):
         node_id = 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee'
-        node = _get_cached_node(id=node_id)
-
-        self.mock_conn.get_node.return_value = node
         instance = fake_instance.fake_instance_obj(self.ctx,
                                                    node=node_id)
         network_info = utils.get_test_network_info()
         self.driver.plug_vifs(instance, network_info)
 
-        self.mock_conn.get_node.assert_called_once_with(
-            node_id, fields=ironic_driver._NODE_FIELDS)
-        mock__plug_vifs.assert_called_once_with(node, instance, network_info)
+        mock__plug_vifs.assert_not_called()
 
     @mock.patch.object(FAKE_CLIENT.node, 'vif_attach')
     def test_plug_vifs_multiple_ports(self, mock_vatt):
@@ -2160,11 +2155,17 @@ class IronicDriverTestCase(test.NoDBTestCase):
         self.driver.unplug_vifs(instance, network_info)
         self.assertFalse(mock_vdet.called)
 
-    @mock.patch.object(ironic_driver.IronicDriver, 'plug_vifs')
+    @mock.patch.object(ironic_driver.IronicDriver, '_plug_vifs')
     def test_attach_interface(self, mock_pv):
-        self.driver.attach_interface('fake_context', 'fake_instance',
+        node_uuid = 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee'
+        node = _get_cached_node(uuid=node_uuid)
+        instance = fake_instance.fake_instance_obj(self.ctx,
+                                                   node=node_uuid)
+        self.mock_conn.get_node.return_value = node
+
+        self.driver.attach_interface('fake_context', instance,
                                      'fake_image_meta', 'fake_vif')
-        mock_pv.assert_called_once_with('fake_instance', ['fake_vif'])
+        mock_pv.assert_called_once_with(node, instance, ['fake_vif'])
 
     @mock.patch.object(ironic_driver.IronicDriver, 'unplug_vifs')
     def test_detach_interface(self, mock_uv):
@@ -2440,17 +2441,23 @@ class IronicDriverTestCase(test.NoDBTestCase):
     def test_get_volume_connector_no_ip_no_fixed_ip(self):
         self._test_get_volume_connector_no_ip(False, no_fixed_ip=True)
 
-    @mock.patch.object(ironic_driver.IronicDriver, 'plug_vifs')
+    @mock.patch.object(ironic_driver.IronicDriver, '_plug_vifs')
     def test_prepare_networks_before_block_device_mapping(self, mock_pvifs):
+        node_uuid = 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee'
+        node = _get_cached_node(uuid=node_uuid)
+        self.mock_conn.get_node.return_value = node
         instance = fake_instance.fake_instance_obj(self.ctx)
         network_info = utils.get_test_network_info()
         self.driver.prepare_networks_before_block_device_mapping(instance,
                                                                  network_info)
-        mock_pvifs.assert_called_once_with(instance, network_info)
+        mock_pvifs.assert_called_once_with(node, instance, network_info)
 
-    @mock.patch.object(ironic_driver.IronicDriver, 'plug_vifs')
+    @mock.patch.object(ironic_driver.IronicDriver, '_plug_vifs')
     def test_prepare_networks_before_block_device_mapping_error(self,
                                                                 mock_pvifs):
+        node_uuid = 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee'
+        node = _get_cached_node(uuid=node_uuid)
+        self.mock_conn.get_node.return_value = node
         instance = fake_instance.fake_instance_obj(self.ctx)
         network_info = utils.get_test_network_info()
         mock_pvifs.side_effect = ironic_exception.BadRequest('fake error')
@@ -2458,7 +2465,7 @@ class IronicDriverTestCase(test.NoDBTestCase):
             ironic_exception.BadRequest,
             self.driver.prepare_networks_before_block_device_mapping,
             instance, network_info)
-        mock_pvifs.assert_called_once_with(instance, network_info)
+        mock_pvifs.assert_called_once_with(node, instance, network_info)
 
     @mock.patch.object(ironic_driver.IronicDriver, 'unplug_vifs')
     def test_clean_networks_preparation(self, mock_upvifs):