Comment 10 for bug 1444112

Reviewed: https://review.openstack.org/174588
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=868e67b480b08cc815d802cf950547c6b5ac0153
Submitter: Jenkins
Branch: master

commit 868e67b480b08cc815d802cf950547c6b5ac0153
Author: armando-migliaccio <email address hidden>
Date: Thu Apr 16 12:45:32 2015 -0700

    Add security groups events

    ML2 mech drivers have no direct exposure to security groups,
    and they can only infer them from the associated network/ports.
    This is problematic as agentless ML2 mech drivers have no way of
    intercepting securitygroups events and propagate the information
    to their backend, or more generally, react to them.

    This patch leverages the callback registry to dispatch such events
    so that interested ML2 mech drivers (or any interested party like
    service plugins) can be notified and react accordingly.

    This patch addresses create/update/delete of security groups and
    create/delete of security groups rules. Other events may be added
    over time, if need be.

    This patch is only about emitting the events. The actual subscription
    and implementation of the event handlers will have to take place where
    deemed appropriate.

    Closes-bug: #1444112

    Change-Id: Ifa1d7ee9c967576f824f1129dd68e6e3abd48f5c