Nix: make configuration persist

[BlueskyFR]

Using the Home Manager module on NixOS, it would be convenient to find a way to make the configuration persist.

Currently, the only thing we can do is create a default config if it doesn't yet exist.

I'm not sure how other projects similar to this one are handling that but by Nix's design we should be able to make the configuration persistent in some way!

I can help on that if needed!

[BlueskyFR]

In the meantime, I did that on my end:

  # Overwrite DMS' config with ours every time instead of on first install only
  xdg.configFile."DankMaterialShell/settings.json" = {
    force = true;
    source = ./settings.json;
  };

It's just a top-of-mind idea but it would be nice to have the settings.json managed by Nix as done here but DMS could write to it instead (not the case with that expression) so that we could update the "source" settings.json whenever we made a change imperatively, if that makes sense?

[HayyaSylvy]

Up this. The worst part is that the module already includes a a nix-way to write the settings file as the defaultSettings option, so it would just be as simple as renaming it to something like mutableSettings and creating a module that actually does setup the settings file as managed by Nix.

[ewtodd]

This has been discussed a lot in #824. The consensus seems to be that nix should control the settings.json, but that requires a change in the quickshell code to make dms write gui settings to a separate file if the existing settings.json is read-only (this mimics the behavior of noctalia). I plan on implementing this at some point, but would be happy if someone got to it before me!

[BlueskyFR]

This has been discussed a lot in #824. The consensus seems to be that nix should control the settings.json, but that requires a change in the quickshell code to make dms write gui settings to a separate file if the existing settings.json is read-only (this mimics the behavior of noctalia). I plan on implementing this at some point, but would be happy if someone got to it before me!

ah this is a great idea! It's a biiit hacky if you ask me because we're asking for changes in the original software just for a Nix use-case but it brings reproducibility so it's a good thing.

I would ask the question of it's the best way to do it or not since my experience with nix is limited, but this seems like a good one!

[ewtodd]

ah this is a great idea! It's a biiit hacky if you ask me because we're asking for changes in the original software just for a Nix use-case but it brings reproducibility so it's a good thing.

I agree it is a bit hacky, but as far as I am aware, the only use case for default-settings.json is Nix, so this sort of feature is not unprecedented.

I would ask the question of it's the best way to do it or not since my experience with nix is limited, but this seems like a good one!

I think long term another solution could be to use json2nix to automatically generate a nix config based on gui settings every time they were changed, but this would introduce many additional complications like the need to specify where it should be saved, whether nix/home-manager should automatically rebuild, etc. Alternatively one could just generate the file and make the user handle placing it in the appropriate place for their system and rebuilding.