deleted_at value in notification messages is wrong

[Phil Day]

The deleted_at value in notification messages is set from the terminated_at value in the instance record.

Note that there is this comment in the notification code:

        # Nova's deleted vs terminated instance terminology is confusing,
        # this should be when the instance was deleted (i.e. terminated_at),
        # not when the db record was deleted. (mdragon)
        deleted_at=null_safe_isotime(instance_ref.get('terminated_at')),

While I can see that there might be some confusion between terminated_at and deleted_at - mapping from one name to the other in the notification message doesn't seem like a great way to resolve it. Surely it would be better to keep the names consistent and include both values in the message - so that the receiver can decide which one they want to use.

This current remapping just enforces one view of difference (or not) between a terminated and a deleted instance

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/47558

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/47558
Committed: http://github.com/openstack/nova/commit/268a7d4e68a567aaeda93c4e828c34701390d7f2
Submitter: Jenkins
Branch: master

commit 268a7d4e68a567aaeda93c4e828c34701390d7f2
Author: Phil Day <email address hidden>
Date: Fri Sep 20 11:38:21 2013 +0000

    Correct deleted_at value in notification messages

    The deleted_at value in notification messages is currently
    set from the terminated_at value in the instance record.

    A comment in the code says this is to avoid confusion between
    terminated_at and deleted_at, but swapping the names doesn't
    seem to be a great way to address that.

    In practice "terminated and not deleted" is a transient state
    unless an error occurs, and the time gap is very short. But
    deleted_at is always set when the entry is deleted in the DB,
    whereas terminated_at can be left unset in some error cases.

    Rather than present terminated_at as the deleted_at value in
    the message we include both and let the recipient decide which
    they want to use.

    Fixes bug: 1227080

    Change-Id: Ic67f66b6c64be1a8f43f4fdd5b1fac25f1414247