Setup flake.nix to provide integration into Nix's flake system

[Roger Qiu]

This repository should have a public flake.nix so it can work seamlessly for downstream users.

Documentation is necessary in the README.md that explains how to make use of this, and how to integrate this into downstream repositories like all of our js-* libraries.

It can also be integrated into people's config.nix so that way one may use nix-env or similar commands. Documentation should be done here.

Tasks

• 1. Create a flake.nix
• 2. Change structure of the repository for proper extension points
• 3. Document the extension points
• 4. Document how users are supposed to integrate this into their development repositories, their user environment and so-on.

[Brynley Llewellyn-Roux]

Something to note I cannot commit empty folders to Git so if you wanted to see the other two folders they will not show up until we put stuff in them.

[Roger Qiu]

We use the .gitkeep pattern to solve that.

[Brynley Llewellyn-Roux]

We should also be pinning upstream nixpkgs and the Polykey-CLI flake; pin the nixpkgs input into this overlay, and pin the upstream Polykey-CLI nixpkgs version to the one in the overlay when used there. The Polykey-CLI flake itself should also be pinned in the overlay.

So something like this:

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs?rev=aaaaaaaaaaaaaaaaa";
    flake-utils.url = "github:numtide/flake-utils";
   
    # Pin polykey-cli nixpkgs version
    polykey-cli.url = "github:MatrixAI/Polykey-CLI?rev=bbbbbbbbbbbbbbbbbb"; # to pin the version of the polykey-cli flake
    polykey-cli.inputs.nixpkgs.follows = "nixpkgs"; # to pin polykey-cli's nixpkgs version to the version of this flake
  };

you can also pin it within the overlay expression itself, will look into all of these options.

[Roger Qiu]

Inputs are constrainted, outputs you can do anything. Are you sure package set registries are expected to put EVERYTHING into the inputs? Sounds like code-smell, there must be a better solution.

[Roger Qiu]

@brynblack so what's the status on putting everything into the inputs?

[Brynley Llewellyn-Roux]

Everything is in the inputs.

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs?rev=a1ff35c63891ec9e4df75189427a5d81b5882bb9"; # Pinned to revision
    flake-utils.url = "github:numtide/flake-utils"; # No pinning needed (doesn't use nixpkgs)

    # Custom packages
    polykey-cli.url = "github:MatrixAI/Polykey-CLI?rev=2bcebd05046bbae86a7b9da67e22613720952627";
    polykey-cli.inputs.nixpkgs.follows = "nixpkgs"; # Inheriting the nixpkgs input above; pinned
  };