Comment 2 for bug 1818693

Reviewed: https://review.openstack.org/641064
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=f08de5cbe9695700e282b9882c661353a2c36d74
Submitter: Zuul
Branch: master

commit f08de5cbe9695700e282b9882c661353a2c36d74
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Tue Mar 5 15:59:00 2019 +0000

    Make "phys_brs" argument in OVSAgentExtensionAPI optional

    In [1], a new init parameter was introduced in the class
    OVSAgentExtensionAPI. This change in the extension API can break
    backwards compatibility with other projects (networking_sfc and
    bagpipe are affected).

    Because this parameter is needed only in qos_driver extension when
    calling OVSAgentExtensionAPI.request_phy_brs() (to retrieve the
    physical bridges list), we can make this new parameter optional not
    to break other stadium projects. When the OVS it's initialized
    (in-tree agent), the extension is called with the three needed
    parameters.

    [1] https://review.openstack.org/#/c/406841/22/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_agent_extension_api.py@43

    Change-Id: I31d1a31a935fdcdd12e13e1bc58f7c5f640ca092
    Closes-Bug: #1818693