Fix issue #5: Refactor default.nix into modular files

[MattiasKockum]

Fixes #5

What changed?

• Split default.nix into:
  installers/default.nix
  installers/netboot.nix
  installers/usb.nix
  registry/default.nix
  dev/ci.nix
  dev/default.nix
  dev/shell.nix
  lib/default-system.nix
• Improved readability and maintainability

Motivation

This refactor prepares the ground for working on features without cluttering default.nix.

How to test?

• nix-instantiate -A usb-installer produces the same hash. Same goes for 'toplevelRegistry'.
• nix-instantiate -A net-installer produces the same error before and after (that could lead to the oppening of a separate issue)
• nix-instantiate -A shell produces a different hash but this is because ci uses src = ../. so any change in the code base actually changes the hash here.

[rlahfa-dinum]

Make it take {, ...} so that we do not have to worry about how many args we pass to it.

[rlahfa-dinum]

Looks good to me, can you add shell.nix at the top-level and ensure that each subfiles have { , ... } to avoid strict argument passing errors?

[MattiasKockum]

Got it! Fixed that missing ellipsis (and checked the other modules had it already)
Regarding shell.nix, I'm not sure of what you're asking. Before the refactor, you had two different shells defined in top-level default.nix and the other in netboot/default.nix. And each of them were pointed to by their corresponding shell.nix.
What I did with my rework was to move the shell from top-level default into its own dev/shell.nix. And this shell is still the same called by doing nix-shell at the top-level.
But I do realize that by that by doing this, I created a new file called shell.nix, that does not have the same function as /netboot/shell.nix.
So either we accept it as-is, or I can merge dev/shell.nix into dev/default.nix to avoid confusion, or I can rename dev/shell.nix with another, clearer, name.
What do you think?

[rlahfa-dinum]

Got it! Fixed that missing ellipsis (and checked the other modules had it already) Regarding shell.nix, I'm not sure of what you're asking. Before the refactor, you had two different shells defined in top-level default.nix and the other in netboot/default.nix. And each of them were pointed to by their corresponding shell.nix. What I did with my rework was to move the shell from top-level default into its own dev/shell.nix. And this shell is still the same called by doing nix-shell at the top-level. But I do realize that by that by doing this, I created a new file called shell.nix, that does not have the same function as /netboot/shell.nix. So either we accept it as-is, or I can merge dev/shell.nix into dev/default.nix to avoid confusion, or I can rename dev/shell.nix with another, clearer, name. What do you think?

No, I meant that it should still be possible to enter into the development shell of the project by having a development shell at the root of the Git repository. You can keep the name as-is, but it would be good to have a top-level shell that forwards to dev/shell.nix (or it can be a dev/default.nix exposing a shell attribute, I don't mind either way).

[MattiasKockum]

Ok so then the PR can merged since calling nix-shell at the top level uses ./shell.nix which looks into ./default.nix for a shell which is inherited from dev/shell.nix.
This is the part that does the plumbing in ./default.nix

  installers = import ./installers moduleArgs;
  registry = import ./registry moduleArgs;
  dev = import ./dev moduleArgs;
in
{
  inherit (installers) net-installer usb-installer;
  inherit (registry) terminals toplevelRegistry;
  inherit (dev) shell;
}

And ./dev/shell.nix contains the shell that was in default.nix before the refactor.

So calling nix-shell from top-level essentially works as well as it did before.

[rlahfa-dinum]

LGTM.

[rlahfa-dinum]

It seems like to me that the CI paths might have not been fully adjusted, can you take a look?

[MattiasKockum]

My understanding is that the CI path problem is preexisting to my PR (since the same issue can be found here : https://github.com/cloud-gouv/bureautix-example/actions/runs/27912405996/job/82591697240)
I think I can open separate issue and propose a fix by the end of the day.

[rlahfa-dinum]

My understanding is that the CI path problem is preexisting to my PR (since the same issue can be found here : cloud-gouv/bureautix-example/actions/runs/27912405996/job/82591697240) I think I can open separate issue and propose a fix by the end of the day.

That's fair, can you use rebase instead of merge commits for the PR? Once you are done, we can merge, thanks.