Flask Example Should use Pinned Flask Version

[elibroftw]

Observations

In the python environment example, Flask has no pinned version. Additionally, other python tooling, like uv is completely ignored. If this is supposed to replace other abstract tooling like pip, requirements.txt, uv, poetry, pipfile, it should be more concrete.

Problem

As someone new to Nix (I use it only for work, and don't like modifying anything), but knows Python and Flask, the current Python-Flask example does not factor into consideration real Python Flask backend projects. Existing projects will use at least a requirements.txt, but projects created recently will probably be using poetry or uv. I've personally had to do a Flask v2 to v3 migration, so it is odd that Flask isn't even pinned to a version like 3. How would someone pin to 3.X?

Also, I notice that we are running the Python application in the shell. This is good for a simple hello world app, but when a project is complicated, a Debugger is good. I usually run a debugger using VSCode. It's unclear whether the VSCode Python debugger would work even if it ran inside the nix shell.

Approaches

The example should be applicable to new Python projects as well as existing Python projects that Python developments can migrate. My website's source code has plenty of room for improvement. It uses a requirements.txt file and is deployed on Heroku. It should be deployed using Docker but the dev environment itself could be better. I'll create another issue too regarding "deployment example"

Willing to help?

Only with answering questions / reviewing

[fricklerhandwerk]

Thanks a lot for elaborating. I agree this can and should be improved.

Implementation notes:

• The python example is not really maintained, so no wonder it's not very useful. Anyone feel free to rework it
• From experience, in a tutorial it's best to show exactly one way of doing things and then direct learners to follow-up resources.
• We chose the greenfield approach here, because it's the most reliable with the fewest moving parts. This may be worth noting.
• What's likely missing here are links to the Nixpkgs manual which should list all the ways on can work with Python.
• In this case we're using the Flask from a certain Nixpkgs release, there's no ambiguity which one that will be. It's probably good to note that, as it may not be evident to beginners, and possibly also how to inspect which version that is and where to find others.

[rkiddy]

Hm. I am looking at this issue. I am just very new to nix, but have been using flask for a few years. My main web site is a (rather large) flask app. I deploy it with apache/mod_wsgi.

I am wondering if it is wise to use nix in this context. Or if I would do better starting with something else.

Actually. Pointing the wsgi variables to the paths provided by nix would not be difficult. I am just not sure there is much reason to do it. And the python page on the wiki does not make a particularly clear case for it. :--)

I also run some scrapers using python selenium. Nix could be nice there, too. It would be helpful to more easily shard instances of the scrapers.

Any suggestions?

[elibroftw]

Docker + Caddy + ansible is what I use right now