router_centralized_snat not removed when router migrated from DVR to HA

[venkata anil]

When a router is migrated from DVR to HA, all ports related to DVR should be removed. But I still see port with device_owner router_centralized_snat not removed.

Steps to reproduce:
1) create a network n1, and subnet on this network with name sn1
2) create a DVR, attach it to sn1 through router interface add and set gateway(router-gateway-set public)
3) boot a vm on n1 and associate a floating ip
4) set admin-state to False i.e neutron router-update --admin-state-up False <router-id>
5) Now update the router to HA router i.e
   neutron router-update --distributed=False --ha=True <router-id>
6) neutron port-list and also
   "select * from ports where device_id="router-id";
   will show this "network:router_centralized_snat" port

[Swaminathan Vasudevan (swaminathan-vasudevan)]

So are you converting from DVR non-HA to DVR-HA or converting DVR to legacy router HA.
Can you confirm.

[venkata anil (anil-venkata)]

While debugging migration tests failures for gate-tempest-dsvm-neutron-dvr-multinode-scenario-ubuntu-xenial-nv job, I observed that snat port is not removed after cleanup of DVR router interface. I see this issue intermittently. Next time when I see the issue I will upload tempest logs.

[venkata anil (anil-venkata)]

I suspect below code

https://github.com/openstack/neutron/blob/master/neutron/db/l3_dvr_db.py#L542

        ports = [
            rp.port.id for rp in
            router.attached_ports.filter_by(
                    port_type=const.DEVICE_OWNER_ROUTER_SNAT)
            if rp.port
        ]

        c_snat_ports = self.l3plugin._core_plugin.get_ports(
            context,
            filters={'id': ports}
        )
Here get_ports() depends on router.attached_ports. If router.attached_ports got deleted(because of router delete immediately after interface delete API call) though port might still exist in DB, then get_ports() can't return snat ports.

Instead we can call get_ports directly i.e
        c_snat_ports = self.l3plugin._core_plugin.get_ports(
            context,
            filters={'device_owner': [const.DEVICE_OWNER_ROUTER_SNAT],
                     'device_id': [router_id]}
        )

I have seen this in my logs earlier(intermittent). If I hit this issue again I will attach logs.
Let this bug be in incomplete state till I get logs.

[venkata anil (anil-venkata)]

This is a valid bug

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/501717

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/501717
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=777fb2af455eea31f9c6ea1f0e260ee8d4d0dbd7
Submitter: Jenkins
Branch: master

commit 777fb2af455eea31f9c6ea1f0e260ee8d4d0dbd7
Author: venkata anil <email address hidden>
Date: Thu Sep 7 12:36:05 2017 +0000

    Remove csnat port when DVR migrated to non-DVR

    When a router is migrated from DVR to HA or DVR to centralized router,
    router_centralized_snat port still exists in DB. When the router is no
    more a DVR router, this port is useless and has to be removed from DB.

    This patch removes router_centralized_snat port when a router is
    migrated from DVR to other modes.

    Closes-Bug: 1714251
    Change-Id: I124514d021ff8539ac3a628907cb49611ef66d08

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/504034

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/pike
Review: https://review.openstack.org/504082

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/504082
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=4089a49d348f4dcfbf38ad8b8dc9672535202cc9
Submitter: Jenkins
Branch: stable/pike

commit 4089a49d348f4dcfbf38ad8b8dc9672535202cc9
Author: venkata anil <email address hidden>
Date: Thu Sep 7 12:36:05 2017 +0000

    Remove csnat port when DVR migrated to non-DVR

    When a router is migrated from DVR to HA or DVR to centralized router,
    router_centralized_snat port still exists in DB. When the router is no
    more a DVR router, this port is useless and has to be removed from DB.

    This patch removes router_centralized_snat port when a router is
    migrated from DVR to other modes.

    Closes-Bug: 1714251
    Change-Id: I124514d021ff8539ac3a628907cb49611ef66d08
    (cherry picked from commit 777fb2af455eea31f9c6ea1f0e260ee8d4d0dbd7)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 11.0.1 release.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/504034
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=1cf6806043cee21ea4afb98c3d18e7b80fb11e80
Submitter: Jenkins
Branch: master

commit 1cf6806043cee21ea4afb98c3d18e7b80fb11e80
Author: Dongcan Ye <email address hidden>
Date: Thu Sep 14 19:12:51 2017 +0800

    Add a test csnat port removing in DVR migration

    This is an additional test for deleting csnat port when
    migrating DVR router to HA router.

    Change-Id: I4a2365fe3a64b65034280558ffe6312d8dabd600
    Partial-Bug: #1714251

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 12.0.0.0b1 development milestone.