Add cachix caches declaratively. You can use it either as a system module, or as a home-manager module.

Import default.nix into your system configuration. This adds the top-level cachix option, which you can use to add cachix caches. You can either pass them as names, or as {name, sha256} attribute pairs.

Example configuration:

  {
    imports = [
      (import (builtins.fetchTarball "https://github.com/jonascarpay/declarative-cachix/archive/a2aead56e21e81e3eda1dc58ac2d5e1dc4bf05d7.tar.gz"))
    ];

    cachix = [
      { name = "jmc"; sha256 = "1bk08lvxi41ppvry72y1b9fi7bb6qvsw6bn1ifzsn46s3j0idq0a"; }
      "iohk"
    ];
  }

Home-manager does not contain a mechanism for declaratively adding caches like the system config does. This module adds that by generating a .config/nix/nix.conf file declaratively.

This has two important implications:

1. If you already have entries in that file aside from the default nix cache, you need to move those to home.file.nixConf.text so they get included in the generated file.
2. If the file is somehow malformed, it will break home-manager itself, so you then have to manually delete it and fix your config. I haven't had any issues myself, but caveat emptor.

Import home-manager.nix into your home-manager configuration. This adds two user-facing options; caches.extraCaches and caches.cachix. There's also caches.caches, but you typically don't want to set this manually since it also adds the normal nix hydra.

Note that you need to be a trusted user to be able to specify caches. See this issue for more information.

Example configuration:

  {
    imports = [
      (
        let
          declCachix = builtins.fetchTarball "https://github.com/jonascarpay/declarative-cachix/archive/a2aead56e21e81e3eda1dc58ac2d5e1dc4bf05d7.tar.gz";
        in import "${declCachix}/home-manager.nix"
      )
    ];

    caches.cachix = [
      { name = "jmc"; sha256 = "1bk08lvxi41ppvry72y1b9fi7bb6qvsw6bn1ifzsn46s3j0idq0a"; }
      "nix-community"
    ];

    caches.extraCaches = [
      {
        url = "https://hydra.iohk.io";
        key = "hydra.iohk.io:********************************************";
      }
    ];
  }