nixos-config/nixos/roles/fonts.nix

{ config, pkgs, lib, ... }: {
  fonts = {
    fontconfig = {
      enable = true;
      cache32Bit = true;
      defaultFonts = {
        monospace = [ "JetBrainsMono Nerd Font" "DejaVu Sans Mono" ];
        sansSerif = [ "B612" "DejaVu Sans" ];
        serif = [ "Libertinus" "DejaVu Serif" ];
      };
    };
    enableDefaultFonts = true;
    #fontDir.enable = true;
    fonts = builtins.attrValues {
      inherit (pkgs)
        nerdfonts# For all my terminal needs.
        libertinus# nice text font
        material-icons# icons in my app
        b612; # sans font, very good for displays
    };
  };

  # create a cache of the font sources, often slow internet connections make it painful to
  # re-download them after a few months
  environment.etc =
    let
      # fonts with src attributes
      font_sources = map (v: v.src) (lib.filter (v: v ? src) config.fonts.fonts);
    in
    builtins.listToAttrs (lib.imap0
      (n: v:
        lib.nameValuePair "src-cache/fonts/${toString n}" {
          source = builtins.toPath v;
        })
      font_sources);
}