This migration was added in Ocata and backported to Newton in change
I8a05ee01ec7f6a6f88b896f78414fb5487e0071e to deal with Mitaka-era
build_requests records that would not have an instance_uuid value
and thus raise a ValueError in BuildRequest._from_db_object (because
BuildRequest.instance_uuid is not nullable).
This is essentially a revert of that change now since operators
have had long enough to run the migration. If anyone were to skip
level upgrade from Mitaka to Train (which we don't support, we require
you to roll through), and hit an issue with this they could simply
execute this on their nova_api DB:
DELETE FROM build_requests WHERE instance_uuid IS NULL;
Change-Id: Ie9593657544b7aef1fd7a5c8f01e30e09e3fcce6
Matt Riedemann
aaee893a5e