Added nix for developer setup (#1379) - Asking for feedback

[daveoconnor]

This PR isn't to be merged, I'm posting it just to solicit feedback.

I've talked with Greg and done a demo, now making it more widely available for feedback before I carry out the rest of the work of consolidating/updating the docs, but this is an important change that should have general buy in before I proceed.

What I'm proposing is docs/nix_based_setup.md becomes the README.md and the only install documentation we have. I may move content from other documentation to here as I consolidate. General information docs will remain separate. I'm thinking the readme should be setup + an index of other docs.

For those who aren't aware, Nix is a package manager which you can consider as similar to brew, but can be declarative like having a package.json/requirements.txt (see flake.nix) and can be limited to a single project, like it is here for website-v2. There's a video linked in docs/nix_based_setup.md that covers Nix.

What this will provide is a system that should be much easier to start with, it sets up all dependencies, asciidoctor and the boost gem etc., sets up a virtualenv, compiles all the json out of the gate, and should allow a developer to be up and running with a complete system (as far as I'm aware of it now) for the project quickly.

There are bootstrap scripts in docs/scripts already that could be useful but would need updating. Personally I'm wary of running scripts that make wide ranging changes to my system and am of the opinion it's easier/quicker to follow instructions than read the scripts to see if there might be issues or collisions with how I normally do things, or might not have been maintained, but I might be in the minority there, so I'd like feedback on that too.

Happy to do another demo if people want to know what it will look like or have questions.

Please add anyone else you think may be useful to provide feedback as a reviewer.

[sdarwin]

It seems that in both scenarios (nix, not-nix) the developer must install.

• Docker Desktop
• Just

Next, it's common to have Python and Git installed anyway.

That leaves... pip, gems, nvm. These might be a convenient advantage of nix. But nix is not the only solution:

• Python virtual environments are a way to switch between multiple sets of python packages.
• nvm is a way to switch between multiple versions of node.

The reviewers tagged in this issue should weigh in. They will be using this on a regular basis. It's a comparison between "I am comfortable with the current setup" versus being enthusiastic about nix. Especially - if Julio, Rob, Chrissy could try this in real life, make an informed decision, and provide feedback/comments.

I wonder if both scenarios could continue to be supported (nix, not-nix). Well, let's see what the feedback is.

[cdw9]

This worked pretty smoothly for me on macOS. I used Docker Desktop.

Issues I ran into:

1. I got an error on the libraries migration 0020_repopulate_slug_20240325_1616: psycopg2.errors.UndefinedColumn: column libraries_library.graphic does not exist. I'm not sure if this is related to nix, it might just be a migration issue that needs to be fixed (I was able to hack my way around it)
2. I got a message like this a few times: direnv: error /nix-website-v2/.env is blocked. Run 'direnv allow' to approve its content. Is there a way to avoid it?