Fix error when deleting a non-existent port

Fixes an issue seen during node tear down where a port being deleted by
the Bare Metal service could be deleted by the Compute service, leading
to an unhandled error from the Networking service. This change simply
ignores the PortNotFoundClient exception raises, as is done when
attempting to unbind a port that does not exist. See [1] for details.

[1] https://storyboard.openstack.org/#!/story/2002637>

Change-Id: Icd2aaa1276e75f08f99553bbc9a873102d896fb9
Story: 2002637
Task: 22285

ironic/common/neutron.py

@@ -338,6 +338,9 @@ def remove_neutron_ports(task, params):
 
         try:
             client.delete_port(port['id'])
+        # NOTE(mgoddard): Ignore if the port was deleted by nova.
+        except neutron_exceptions.PortNotFoundClient:
+            LOG.info('Port %s was not found while deleting.', port['id'])
         except neutron_exceptions.NeutronClientException as e:
             msg = (_('Could not remove VIF %(vif)s of node %(node)s, possibly '
                      'a network issue: %(exc)s') %

ironic/tests/unit/common/test_neutron.py

@@ -467,6 +467,18 @@ class TestNeutronNetworkActions(db_base.DbTestCase):
         self.client_mock.delete_port.assert_called_once_with(
             self.neutron_port['id'])
 
+    def test_remove_neutron_ports_delete_race(self):
+        with task_manager.acquire(self.context, self.node.uuid) as task:
+            self.client_mock.delete_port.side_effect = \
+                neutron_client_exc.PortNotFoundClient
+            self.client_mock.list_ports.return_value = {
+                'ports': [self.neutron_port]}
+            neutron.remove_neutron_ports(task, {'param': 'value'})
+        self.client_mock.list_ports.assert_called_once_with(
+            **{'param': 'value'})
+        self.client_mock.delete_port.assert_called_once_with(
+            self.neutron_port['id'])
+
     def test_get_node_portmap(self):
         with task_manager.acquire(self.context, self.node.uuid) as task:
             portmap = neutron.get_node_portmap(task)

releasenotes/notes/story-2002637-4825d60b096e475b.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixes an issue seen during node tear down where a port being deleted by the
+    Bare Metal service could be deleted by the Compute service, leading to an
+    unhandled error from the Networking service. See `story 2002637
+    <https://storyboard.openstack.org/#!/story/2002637>`__ for further details.