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On 10/29/20 1:45 PM, Rabi Mishra wrote:
> On Thu, Oct 29, 2020 at 4:59 PM Bogdan Dobrelya <bdobreli at redhat.com 
> <mailto:bdobreli at 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.

Yes, that change belongs to a massive conversion effort that contains 
hundreds of patches in the topic. Also the created ansible module 
doesn't look trivial to me, since the result [0] of that work looked 
much simpler than the original parts [1], [2], [3] of workflow and its 
code. And "trivial" playbook for the given example only wraps the 
ansible module for the caller. So that approach taken for that example 
looks justified.

[0] 
https://review.opendev.org/#/c/712604/7/tripleo_ansible/ansible_plugins/modules/tripleo_plan_parameters_update.py

[1] 
https://review.opendev.org/#/c/298682/23/tripleo_common/actions/parameters.py

[2] 
https://review.opendev.org/#/c/716286/4/tripleoclient/v1/overcloud_deploy.py

[3] https://review.opendev.org/#/c/540398/2/workbooks/plan_management.yaml

> 
> 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
> 


-- 
Best regards,
Bogdan Dobrelya,
Irc #bogdando