Description of problem:
For OSP13 all the upgrades related clis ("openstack overcloud upgrade", "openstack overcloud update", "openstack overcloud ffwd-upgrade") have a 'prepare' subcommand where we generate ansible playbooks with a heat stack update. During this stack update we 'noop' the deployment config since we don't want config applied during this step. This is achieved with  to set and  to unset.
Doing this is not scalable as we now have to add more resources for no-op specific to the ffwd-upgrade cli. Furthermore we would also have to deal with unset of resources used during the major upgrade, such as the UpgradeInitCommand.
Instead we should use environment files specific to each operation and which will be inserted into the heat call by the tripleoclient.
*** Bug 1568548 has been marked as a duplicate of this bug. ***
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.