neutron doesnt delete port binding level when deleting an inactive port binding

[Adrian Chiris]

When performing VM live migration with a normal port (OVS mechanism driver) nova creates an in-active binding on the destination node then activates that binding upon successful migration.

in case of failure to migrate with libvirt, an exception is raised, nova performs a rollback operation for the live migration and instance remains in running state on the source node.

part of the rollback operation is deleting neutron's port binding on the destination node with the following API call:
DELETE /v2.0/ports/​{port_id}​/bindings/{host_id}

this call, for an inactive port binding (which was never activated), does not delete the port's binding level which causes future migration attempts to fail.

Reproduction setup:
- devstack deployment of an all in one and a compute node from master
- OS: FC28
- QEMU hypervisor
- neutron OVS mechanism driver enabled
- perform further configurations to enable live-migration : https://docs.openstack.org/nova/pike/admin/configuring-migrations.html
- block libvirt migration port with iptables on destination node (on my setup i just needed to activate iptables on destination node)

reproduction steps:
http://paste.openstack.org/show/744802/

[Adrian Chiris (adrian.chiris)]

the following patch proposes a fix to the issue:

https://review.openstack.org/#/c/634276/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/rocky
Review: https://review.openstack.org/641042

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/634276
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=b197f7c1c4b9c0dd4c58f5c5a4b654dde5596b85
Submitter: Zuul
Branch: master

commit b197f7c1c4b9c0dd4c58f5c5a4b654dde5596b85
Author: Adrian Chiris <email address hidden>
Date: Thu Jan 31 18:51:33 2019 +0200

    Delete port binding level for deleted bindings

    Today, if live migration has failed after an inactive
    binding was created on the destination node but before
    the activation of the created binding, the port's binding level
    for the destination host is not cleared during nova's API call
    to neutron to delete the port binding.

    This causes future attempts to perform live migration
    of the instance to the same host to fail.

    This change removes port binding level object during port binding
    deletion.

    Closes-Bug: #1815345

    Change-Id: Idd55f7d24a2062c08ac8a0dc2243625632d962a5

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 14.0.0.0b3 development milestone.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/641042
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=28a7dd12fef78857a0c0f347cf11a63091ea0f5a
Submitter: Zuul
Branch: stable/rocky

commit 28a7dd12fef78857a0c0f347cf11a63091ea0f5a
Author: Adrian Chiris <email address hidden>
Date: Thu Jan 31 18:51:33 2019 +0200

    Delete port binding level for deleted bindings

    Today, if live migration has failed after an inactive
    binding was created on the destination node but before
    the activation of the created binding, the port's binding level
    for the destination host is not cleared during nova's API call
    to neutron to delete the port binding.

    This causes future attempts to perform live migration
    of the instance to the same host to fail.

    This change removes port binding level object during port binding
    deletion.

    Closes-Bug: #1815345

    Change-Id: Idd55f7d24a2062c08ac8a0dc2243625632d962a5
    (cherry picked from commit b197f7c1c4b9c0dd4c58f5c5a4b654dde5596b85)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 13.0.3 release.