Burton update build env pt4

[bdewilde]

changes

• adds a bare-bones and not-fully-functional docker setup for app (api) and database services
• updates application env vars and configuration setup, now marginally better but still WIP
• tightens up db-oriented app dependencies: alembic, psycopg2(-binary), sqlalchemy
• adds a mirror of app dependencies from pyproject.toml into prod/dev requirements files, which are intended only for better caching docker builds
• adds very basic test for app configs

questions

• i could not find a single decent, full example of a flask rest api w/ postgresql db in a dockerized setup. and since i'm not a docker expert, this was a real struggle. it doesn't totally work. not a specific question, but: how can i make this better??
• similarly, i couldn't find a single decent, full example of testing a flask rest api w/ postgresql db. truly amazed by this, there is a ton of low-quality information online. any advice here?

[bdewilde]

thanks for taking a look @samanz . here are the use cases i'd like to support:

• local development work, with a db that starts from scratch and can be populated with data as needed by the dev
• CI testing via GitHub Actions, with a db that starts from scratch and has standard seed data loaded in
  • local testing, with the same setup
• deployment to stage and/or prod systems

[samanz]

cool, and when you say "it doesn't totally work" what isn't working now?

[bdewilde]

that comment was left regarding an older version of these changes -- a few commits back -- and i don't remember exactly what i was referring to. probably that i couldn't access the api via a web browser, it was saying that the connection had been reset; that is no longer the case, fortunately. i can say that, using the latest revision of this branch, the worker service dies immediately, which is not ideal.

[bdewilde]

would it be easier if i just merged this into dev, then started hacking on a new branch? i really want to set up a basic unit testing suite -- and maybe the current setup here will work for that? not sure -- and then blacken the entire code base. not sure if you have other work that goes better in parallel, or are you a bit blocked by those two steps as well?

[samanz]

I do eventually want to move the scala code to python, and I would just add that to the flask API. I want to wait until you have things stabilized here before starting that work. I can work on testing models independently though, so not blocked on working on anything. I'd be nice if we can have the docker setup be stable, and that can be the version we launch on the staging box. It'll also make my development env setup easier. I'm happy to help get the docker env up.

[bdewilde]

i would love some help in getting the docker setup -- part of the stabilization project -- working as expected, since i don't have much experience with it. to that end, i'll merge these changes into dev, then start a new branch+PR focused on docker stuff that we can both hack on. part of that will hopefully be basic unit testing and usage instructions leveraging the docker builds. will tag you over there....