port in use can be deleted by neutron, left an orphan interface in vm

[Zang MingJie]

Way to reproduce:

nova boot --flavor m1.tiny --image cirros-0.3.1-x86_64-uec test
neutron port-delete c702e88f-f249-48fa-90fd-00397e681814 (id of the port assigned to the vm)

result:

left an unmanaged interface in vm, nova info cache and neutron port database de-sync.

$ nova list
+--------------------------------------+------+--------+------------+-------------+------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+------+--------+------------+-------------+------------------+
| 202abd0d-d459-4026-9ec9-0b2493ff7371 | test | ACTIVE | - | Running | private=10.0.0.4 |
+--------------------------------------+------+--------+------------+-------------+------------------+
$ nova interface-list test
+------------+---------+--------+--------------+----------+
| Port State | Port ID | Net ID | IP addresses | MAC Addr |
+------------+---------+--------+--------------+----------+
+------------+---------+--------+--------------+----------+

potential fix:

Forbid to delete a port which is in use

[Eugene Nikanorov (enikanorov)]

I'm not sure how this can be handled by neutron, especially that the described behavior is somewhat expected.
VM's port belong to a tenant, so tenant may need to have control.
Technically it's not quite clear what is 'port is in use'.

[Tiantian Gao (gtt116)]

@Eugene

I don't agree with you. We would like Neutron to be a robust program, when user submitted an error input if we can't gracefully process it, ignoring the risk, and letting it happened not looks good. It is our duty to warn them that the action is dangerous, and reject the request for protecting the system.

In cinder, when a volume is attached, cinder will reject user to delete the volume before detach it. I think we can follow this pattern to return a 400 to user if he want to delete a 'in use' port. Although an alternative solution is leaving a message about this in network documents, but I don't think it's a good choice. :)

[Tiantian Gao (gtt116)]

How about defining a port is 'in used' if it's device_owner, device_id is not None?

[Eugene Nikanorov (enikanorov)]

Yep, that's what I was asking about. Right now every of these fields can be updated by user, in other words, user may make port 'not in use' by this definition.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/99358

[OpenStack Infra (hudson-openstack)]

Change abandoned by Zang MingJie (<email address hidden>) on branch: master
Review: https://review.openstack.org/99358

[Cedric Brandily (cbrandily)]

This bug is > 365 days without activity. We are unsetting assignee and milestone and setting status to Incomplete in order to allow its expiry in 60 days.

If the bug is still valid, then update the bug status.

[Launchpad Janitor (janitor)]

[Expired for neutron because there has been no activity for 60 days.]