On Thu, Oct 29, 2020 at 4:59 PM Bogdan Dobrelya <bdobreli@redhat.com> wrote:

Hi,

In today TripleO client development we invoke ansible playbooks instead
of Mistral workflows. I believe this may only be justified for
non-trivial things. Otherwise please just import python modules into the
client command actions without introducing additional moving parts in
the form of ansible modules (that import the same python modules as well).

Ansible brings declarative DSL that sometimes can better and simpler and
faster describes things to do and shape inputs data, than if the same
would be done in python, in the client.

What should be the trivial thing and non-trivial then?

Yes, we did create a number of playbooks/ansible modules for some trivial things starting with https://review.opendev.org/#/c/716286/ (I had a comment about it in that patch and it seems you reviewed the patch too), that could have been achieved by making a simple tripleo-common api calls.

IMO, creating playbooks for every cli action and moving all logic from tripleoclient to ansible modules/playboos would have helped us in either getting rid of tripleoclient or make it very thin. We did discuss that in the victoria PTG[1]. Agreed that we would end up with some inefficient stuff (like what you've mentioned) during the transition and later, but the user experience with ansible playbooks compared to current logging in cli actions would have outweighed that.

However, over the last cycle I've seen some resistance to go in that direction (i.e moving everything from tripleoclient to playbooks/role/ansible mddules), If we want to keep some stuff in tripleolcient (and some in ansible modules/playbooks), then I would agree we should not make it complex by writing playbooks/modules for things that could be achieved by simple tripleo-common api calls.

[1] https://etherpad.opendev.org/p/tripleo-future-of-tripleoclient

Well, I think that example [0] illustrates such a trivial thing. A new
playbook [1] would only install a few packages then "returns" back into
python and calls a new ansible module [2]. And that new module only
wraps [3] the same code being removed from the client:

from tripleo_common.image import build
...
manager = build.ImageBuildManager(<args>)

I see no point of adding a new playbook and a new module for that
trivial example. Those 4 packages could (and should) be as well
installed from the client caller code without any ansible involved in
the middle IMO.

[0] https://review.opendev.org/#/c/759954/

[1]
https://review.opendev.org/#/c/759953/3/tripleo_ansible/playbooks/cli-overcloud-image-build.yaml

[2]
https://review.opendev.org/#/c/759953/3/tripleo_ansible/ansible_plugins/modules/tripleo_overcloud_image_build.py@26

--
Best regards,
Bogdan Dobrelya,
Irc #bogdando

Regards,

Rabi Mishra