Comment 4 for bug 1392540

Reviewed: https://review.openstack.org/134744
Committed: https://git.openstack.org/cgit/stackforge/powervc-driver/commit/?id=7fc7fc17e9a41d8450ea750c71d105418453b5f2
Submitter: Jenkins
Branch: master

commit 7fc7fc17e9a41d8450ea750c71d105418453b5f2
Author: Yi Ming Yin <email address hidden>
Date: Fri Nov 14 16:57:01 2014 +0800

    Add extra logic to handle port detach issue

    nova manager will first delete local neutron port before call driver to
    detach port on PowerVC. This behavior will trigger a local port deleted
    event and cause current driver code failed to retrieve remote PowerVC
    port id when doing interface detach

    1. First priority is to use local port id to retrieve remote PowerVC
    port id, which is the current logic.
    2. If local port id cannot be retrieved, it will call interface_list on
    remote PowerVC instance and get all attached interface information. Then
    the code will scan all the local port IP addresses and compare to remote
    IP addresses and find the matched port id to detach.

    Change-Id: I3a87f3780c2cb949a0dc80380a37ab17bb98e059
    Closes-Bug: #1392540
    (cherry picked from commit 8c766d08616b30dae4712f0a586adb28604725d6)