devstack neutron won't create public network unless q-l3 is enabled

[Brad Behle]

The OVN neutron plugin that is under development doesn't use the neutron L3 Agent and instead uses OVS/OVN to handle L3 routing. The gate job that uses OVN for L3 routing instead of neutron L3 agent needs to be able to set up a devstack that does not have the neutron L3 Agent but that DOES have the "public" network (and associated bridge, etc) created.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/304871

[Richard Theis (rtheis)]

Hi Brad, I think the devstack bug can be marked invalid now since this is being working in networking-ovn.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/304859
Committed: https://git.openstack.org/cgit/openstack/networking-ovn/commit/?id=12e5bb646a4e0b43ef4c73bb627480a2dbb3e31c
Submitter: Jenkins
Branch: master

commit 12e5bb646a4e0b43ef4c73bb627480a2dbb3e31c
Author: Brad Behle <email address hidden>
Date: Thu Apr 7 16:35:32 2016 -0500

    Create bridge for OVN L3 in devstack

    When OVN is used for L3 routing in devstack, create the public
    network, subnets, router, and also create the public bridge br-ex.
    This is meant to be equivalent to what happens in devstack when the
    L3 agent is enabled. I hoped to do this by creating a flag that
    could be set by plugins that would trigger the devstack code that
    already exists to do this, but that approach was rejected (see
    https://review.openstack.org/#/c/304871/). So, the next best thing
    is to copy that code from devstack into the networking-ovn devstack
    plugin, which is what I did here.

    Change-Id: I7e17b9f9f967a2625aa81b9dfb50739567cc223c
    Closes-Bug: #1567068