This change has two main parts:
* Ensure that when we ssh *via Mistral*, we always use
tripleo-admin. `--ssh-user` argument to any update/upgrade run
commands is now deprecated. The reason i didn't remove it completely
is that how current upgrade commands use ssh needed some mental
untangling, and i want us to keep an easy way back in case my
understanding is wrong here. Deprecation seems safer than outright
removal.
* On upgrade prepare and FFWD prepare, make sure that the
tripleo-admin user is created and authorized.
Note that for tripleo-admin creation and authorization, the
`--overcloud-ssh-user` parameter is used, and that one still
defaults to `heat-admin`, which is correct. So initially we connect
via whatever credentials user provided (which works on Nova+Ironic
envs unless user customized it), and from that point on we always
use tripleo-admin, which is common for all environments regardless
of any user customizations. This is how deployment already works
now, and after this change upgrades will work that way too.
Change-Id: Ib1a75a0a3f3b2a3bec00d8820c3a097620fa6256
Closes-Bug: #1801066
479a530656