Deleting an HA router with interfaces attached leaves the DB in an inconsistent state

Once system is in this state, l3-agent will be blocked when trying to update routers with an error like this:

2014-12-15 10:35:41.271 6046 ERROR neutron.agent.l3_agent [-] 'NoneType' object has no attribute 'config'
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent Traceback (most recent call last):
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent File "/usr/lib/python2.7/site-packages/neutron/common/utils.py", line 341, in call
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent return func(*args, **kwargs)
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent File "/usr/lib/python2.7/site-packages/neutron/agent/l3_agent.py", line 899, in process_router
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent self.internal_network_added(ri, p)
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent File "/usr/lib/python2.7/site-packages/neutron/agent/l3_agent.py", line 1526, in internal_network_added
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent self._add_vip(ri, internal_cidr, interface_name)
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent File "/usr/lib/python2.7/site-packages/neutron/agent/l3_ha_agent.py", line 169, in _add_vip
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent instance = ri.keepalived_manager.config.get_instance(ri.ha_vr_id)
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent AttributeError: 'NoneType' object has no attribute 'config'
2014-12-15 10:35:41.271 6046 TRACE neutron.agent.l3_agent

My previous comment was wrong, that error didn't block the l3-agent, just stopped the proper creation of
the specific router.

So it's not that critical, yet needs to be fixed, of course.

The actual message of this issue is:

2014-12-14 19:38:18.663 19705 ERROR neutron.agent.l3_ha_agent [-] Unable to process HA router 275af32a-3ada-4374-88a7-69a1191ddde6 without ha port

Fix proposed to branch: master
Review: https://review.openstack.org/144260

Fix proposed to branch: master
Review: https://review.openstack.org/144681

Change abandoned by Yoni Shafrir (<email address hidden>) on branch: master
Review: https://review.openstack.org/144681
Reason: As suggested in several reviews, this change is not desired. a different patch will be sent doing the opposite which is to allow to user to freely remove a router from the same agent twice w/o any error message (today it's a 409 conflict)

Reviewed: https://review.openstack.org/144260
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=7632f5dba619bbd9286708f59c31fa392b9c419c
Submitter: Jenkins
Branch: master

commit 7632f5dba619bbd9286708f59c31fa392b9c419c
Author: Yoni Shafrir <email address hidden>
Date: Mon Dec 22 11:25:39 2014 +0200

    Deleting HA router with attached port causes DB inconsistencies

    When a HA router is being deleted with 'python-neutronclient'
    while it has an attached interface the deletion will fail since
    the router is in use. The order in which the deletion
    is done is - first remove the HA interfaces from DB and
    then delete the router. In this case the HA interfaces were
    indeed deleted but the router itself was not (router is in use).
    This causes the DB to be inconsistent where an HA router
    exists in the DB while it's ports were removed from the DB.

    This patch simply deletes the router first, and then
    we know it's safe to remove it's HA interfaces as
    well. If the router is in use and deletion fails
    the HA interfaces remain intact.

    Closes-Bug: #1402698

    Change-Id: I956d0094ae6e2412e859d79feeb4003941d2bb4b