nix-config/modules/nix-config.org

Nix Configuration

• Nix Configuration

Nix Configuration

Something that I want to enable everywhere is, first and foremost, the support for Nix commands and Nix flakes. I also want to make sure I can use some caches, also known as substituters, including one of mine from Cachix, to avoid compiling stuff as much as possible.

So first, here are my caches with their public key.

Substituter's URL	Public Key
https://phundrak.cachix.org?priority=10	phundrak.cachix.org-1:osJAkYO0ioTOPqaQCIXMfIRz1/+YYlVFkup3R2KSexk=
https://nix-community.cachix.org?priority=20	nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=
https://cache.nixos.org?priority=40	cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=

(mapconcat (lambda (sub) (format "\"%s\"" (car sub))) subs "\n")

"https://phundrak.cachix.org?priority=10"
"https://nix-community.cachix.org?priority=20"
"https://cache.nixos.org?priority=40"

(require 's)
(mapconcat (lambda (sub) (format "\"%s\""
                            (s-chop-prefix "=" (s-chop-suffix "=" (cadr sub)))))
           subs
           "\n")

"phundrak.cachix.org-1:osJAkYO0ioTOPqaQCIXMfIRz1/+YYlVFkup3R2KSexk="
"nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
"cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="

This results in the following substituters and trusted public keys.

substituters = [
  <<substituters-urls()>>
];
trustedPublicKeys = [
  <<substituters-keys()>>
];

Now, we can declare the rest of the file. You’ll see, it repeats itself a bit.

let
  cacheSettings = rec {
    <<config-vars>>
    commonConf = {
      extra-trusted-public-keys = trustedPublicKeys;
      extra-substituters = substituters;
      extra-experimental-features = ["nix-command" "flakes"];
      http-connections = 128;
    };
  };
in {
  flake-file.nixConfig = cacheSettings;
  flake.nixConfig = cacheSettings;
  flake.modules.nixos.nix-cache-settings = {
    nix.settings = {
      inherit (cacheSettings) substituters;
      trusted-public-keys = cacheSettings.trustedPublicKeys;
      experimental-features = ["nix-command" "flakes"];
      http-connections = 128;
    };
  };
}