Notifications missing for instance rescue operation

[Monsyne Dragon]

Most instance operations in Nova (create, resize, delete, etc) emit compute.instance.<operation>.[start |end] events to the notification bus so external systems (such as Ceilometer, or in-house billing systems) can track the state of an instance for billing, metrics, etc.

These are missing for the rescue/unrescue operations. Since a rescue changes an instance's launched_at time, this makes the picture of an instance's state inconsistent for systems consuming the notifications. (Even if a system doesn't really care about rescues, it needs to know they happened to get a correct picture of the instance's running time for, e.g. billing purposes).

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/46134

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/46134
Committed: http://github.com/openstack/nova/commit/fe2b0d37f74a322fe5d6611129f9dd5128488260
Submitter: Jenkins
Branch: master

commit fe2b0d37f74a322fe5d6611129f9dd5128488260
Author: Monsyne Dragon <email address hidden>
Date: Wed Sep 11 19:48:59 2013 +0000

    Add missing notifications for rescue/unrescue

    The rescue and unrescue operations are missing start/end notifications for
    the operation. Most Nova instance operations emit
    compute.instance.<operation>.start/end notifications, which external systems
    can use to track changes in the state on an instance (e.g. for billing
    purposes). Rescues change launched_at for the instance, which can prevent an
    external system from having a consistant picture of the instances' running,
    unless they take that into account.

    Change-Id: I3d7d334c88953ddf693c864c3e5e0746cdd2056c
    Closes-bug: 1224088