Routers may never be torn down if router_delete_namespaces is False

[Carl Baldwin]

The code recently added https://review.openstack.org/#/c/30988/ very nicely cleans out stale routers assuming that self.conf.router_delete_namespaces is true.

The problem is that automatic namespace deletion is still a bit unstable because of problems with the kernel and the iproute utility. So, many users may not have self.conf.router_delete_namespaces set to True. In this case, all of the advantages added by the above mentioned patch don't help us.

The problem arises if a router gets deleted or moved to another agent while the L3 agent is down. When the L3 agent comes back up, it will not touch the router and the router will continue to function as if it were never deleted.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/84570

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/84570
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=8ab6fd6d7e521a3692f57542e5c5c5d513d57ccc
Submitter: Jenkins
Branch: master

commit 8ab6fd6d7e521a3692f57542e5c5c5d513d57ccc
Author: Carl Baldwin <email address hidden>
Date: Tue Apr 1 22:16:59 2014 +0000

    Clean out namespaces even if we don't delete namespaces

    Even when we don't enable namespace deletion, we still want to run the
    code that cleans out the namespaces so that the devices get unplugged,
    etc. Otherwise, routers deleted while the agent is down will continue
    to operate as if they were never deleted.

    The trade-off to consider here is that if there are many stale
    namespaces this will slow down the restart of the L3 agent. The best
    option is to get namespace deletion working correctly. However, where
    that has not been worked out yet, this patch provides the cleaning
    service for deleted routers.

    Change-Id: Ic7b4608a23c4d9530f521d5faff3f8526200b92e
    Closes-Bug: #1301042
    Related-Bug: #1052535