Round-robin SVI switch selection fails on Cisco Nexus plugin

[Dane LeBlanc]

Round-robin SVI switch selection is working incorrectly for the Cisco Nexus plugin.
The expected behavior is that when round-robin SVI switch selection is configured
in cisco_plugins.ini file, i.e.:
    [cisco]
    nexus_l3_enable = True
    svi_round_robin = True
then whenever a virtual router interface is created, the Nexus plugin should
select the Nexus switch with the least number of SVI interfaces already
created for creating a new SVI.
The current behavior is that the wrong Nexus switch is being selected
most of the time.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/56321

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/56321
Committed: http://github.com/openstack/neutron/commit/6b21cd29bec6b4c069eeda5bfd4b40e8d1f2a89e
Submitter: Jenkins
Branch: master

commit 6b21cd29bec6b4c069eeda5bfd4b40e8d1f2a89e
Author: Dane LeBlanc <email address hidden>
Date: Wed Nov 13 23:10:21 2013 -0500

    Round-robin SVI switch selection fails on Cisco Nexus plugin

    Fixes bug 1250969

    This fix addresses improper behavior with the Cisco Nexus plugin's
    selection of Nexus switch on which to place a Switch Virtual Interface
    (SVI) when round-robin switch placement is enabled.

    The expected behavior when round-robin SVI switch selection is configured
    via the cisco_plugins.ini file, i.e.:
        [cisco]
        nexus_l3_enable = True
        svi_round_robin = True
    is that when a virtual router interface is created, the Nexus plugin should
    select the Nexus switch with the least number of SVI interfaces configured
    for creating the new SVI. The current selection is based on the first
    entry in a dictionary, and is therefore indeterminate.

    Similarly, this fix also addresses incorrect behavior when round-robin
    selection is disabled. In this case, the desired behavior is that
    the plugin should select the first switch which appears in the Nexus
    switch configuration. Instead, the current selection is also based on the
    first entry in a dictionary, and is likewise indeterminate.

    Change-Id: I548c1efaa8b54695246251b6823ab59e077836fe