Comment 9 for bug 1816698

Reviewed: https://review.openstack.org/642348
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=2e033b3b0d57268856eb453802148129ebd0c954
Submitter: Zuul
Branch: stable/queens

commit 2e033b3b0d57268856eb453802148129ebd0c954
Author: Swaminathan Vasudevan <email address hidden>
Date: Thu Feb 21 17:14:03 2019 -0800

    DVR-HA: Unbinding a HA router from agent does not clear HA interface

    Removing an active or a standby HA router from an agent that has a
    valid DVR serviceable port (such as DHCP), does not remove the
    HA interface associated with the Router in the SNAT namespace.

    When we try to add the HA router back to the agent, then it
    adds more than one HA interface to the SNAT Namespace causing
    more problems and we sometimes also see multiple active routers.

    This bug might have been introduced by this patch [1].

    Fix the problem by just adding the router namespaces without HA
    interfaces when there is no HA and re-insert the HA interfaces
    when HA router is bound to the agent into the namespace.

    [1] https://review.openstack.org/#/c/522362/
    Closes-Bug: #1816698

    Change-Id: Ie625abcb73f8185bb2bee06dcd26a01d8af0b0d1
    (cherry picked from commit d9e0bab6acf6a608ed5bf32524c7d362f052a3ac)