# hacc nixfiles

welcome to hacc nixfiles (haccfiles). this is the code describing our nix-based infrastructure.

## structure

- `flake.nix`: Entrypoint & dependencies
- `common/`: configuration common to all hosts
- `modules/`: home-grown modules for hacc-specific services
- `pkgs/`: packages we built and don't want to upstream
- `hosts/`: configuration.nix per host (currently there's only one of those)
- `services/`: all services we run; imported in appropriate host config
- `websites/`: static websites we deploy somewhere

## working with the haccfiles

You will need a flake-enabled nix installation, and have your ssh config set up
so that `ssh parsons` will connect to `parsons.hacc.space`.

It's recommended to use [deploy_rs](https://github.com/serokell/deploy-rs):
~~~shell
deploy .#parsons -k [--dry-activate]
~~~

Alternatively, using just `nixos-rebuild`:
~~~shell
nixos-rebuild --flake .#parsons --target-host parsons \
  --use-remote-sudo --use-substitutes [test|switch|dry-activate]
~~~

If for some reason you have `nix` but not `nixos-rebuild`, you can still build the
system closure using:
~~~shell
nix build .#nixosConfigurations.parsons.config.system.build.toplevel
~~~

(but you might have trouble deploying it)

## I don't want to build this long dependency / want a cached version!

If it's still available on parsons from a previous deploy, do:
```shell
nix copy --from ssh://parsons /nix/store/...
```

Note: don't just copy the .drv file (which Nix complains about if it can't
build something), that's just the description of how to build it! If you
don't know the actual outpath, look in the .drv file (should start with
`Derive([("out","[the path you want]"...`)

## committing to haccfiles
- Things on `main` should always reflect the config that's actually deployed on
  parsons, except during testing / debugging sessions
- split up commits, every commit is one atomic change
- follow the commit format: "place: $change"
  - place: e.g. `modules/$module`, `services/$service` ...
  - change: describe your change. Please wrap your lines sensibly (or configure
    your editor to do this for you)
- Exception: autogenerated messages (merge commits, reverts, etc)
- don't overuse merge commits, try to rebase things if possible with reasonable
  effort