I just finished writing an Ansible installer playbook for one of my projects. I managed to create this proxy/bridge script that serves as an interface between Ansible and Opalstack's API.
https://gist.github.com/webtweakers/4e6af09ebb64fd0352581428d22e0e56
You'll note that I needed to write a find_existing function because the existing functions (like filt_one) in the API's util module were not working in this context. Additionally some things are a little clumsy. For instance trying to GET some info from the API requires jumping through some hoops to get to what you really want. For other things, the API expects a list of arguments (particularly when creating databases, a list of users is expected), which is difficult to supply from Ansible, and requires providing the argument in JSON, which then needs to be parsed. More little difficulties.
All in all not a big deal, these things, but I feel that these things - and probably other things as well - can be optimized and streamlined towards this type of usage. I don't know, just my 2c.
I suggest having a look at the code, and maybe you guys can write your own awesome version and release an official Ansible - Opalstack interface. It could then be added to the Ansible Galaxy Collections.
