my nix darwin-configuration file

darwin-configuration.nix

{ config, pkgs, ... }:

let
  uhome            = builtins.getEnv "HOME";
  uname            = builtins.getEnv "USER";
  tmpdir          = "/tmp";
in {
  imports = [ <home-manager/nix-darwin> ];

  # Use a custom darwin-configuration location.
  # $ darwin-rebuild switch -I darwin-config=$HOME/.config/nixpkgs/darwin-configuration.nix
  environment.darwinConfig = "$HOME/.config/nixpkgs/darwin-configuration.nix";

  # nix has depreciated the aliases binary-cache-public-keys and trusted-binary-caches for nix.conf https://nixos.org/manual/nix/unstable/command-ref/conf-file.html#conf-trusted-public-keys
  nix.settings.substituters = [ 
    https://hydra.iohk.io 
    https://iohk.cachix.org 
    https://cache.iog.io
    https://cache.nixos.org
    https://cache.zw3rk.com
    ssh://hokioi.husky-ostrich.ts.net
  ];
  
  nix.settings.trusted-public-keys = [
    hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= 
    iohk.cachix.org-1:DpRUyj7h7V830dp/i6Nti+NEO2/nhblbov/8MW7Rqoo= 
    cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
    loony-tools:pr9m4BkM/5/eSTZlkQyRt57Jz7OMBxNSUiMC4FkcNfk=
    kupo.cachix.org-1:RzYQ8KVjRJdPNt/Bhq/UqdyGYWFM8ShjEMNG8wzHBQ4=
    hokioi.husky-ostrich.ts.net:pyoBKuk7od8hoBJ93zgyYkFHgLw0ulIqqSFSjcAYj5A=
  ];
  
  nix.settings.trusted-users = [
  "jobrien"
  ];

# Enable experimental nix command and flakes
  
  nix.extraOptions = ''
  auto-optimise-store = true
  experimental-features = nix-command flakes
	allow-import-from-derivation = true
  '';
  
  programs.nix-index.enable = true;
  programs.zsh.enable = true;  # default shell on catalina

  # Add ability to used TouchID for sudo authentication
  security.pam.enableSudoTouchIdAuth = true;  

  # List packages installed in system profile. To search by name, run:
  # $ nix-env -qaP | grep wget
  environment.systemPackages = with pkgs; [ 
      cachix
      coreutils
      gnupg
  ];
  
  # Auto upgrade nix package and the daemon service.
  services.nix-daemon.enable = true;
  nix.package = pkgs.nix;

  users.users.${uname} = {
     name = uname;
     home = uhome;
  };

  home-manager.useGlobalPkgs = false;
  home-manager.users.${uname} = import ./home.nix;

  # Yubikey GPG SSH. Diverting the OSX ssh-agent to use gpg-agent
  # GPG Config
  programs.gnupg.agent = {
    enable = true;
    enableSSHSupport = true;
  };

  # Setup needed environment variables.
  environment.loginShell = "${pkgs.zsh}/bin/zsh -l";
  environment.variables.SHELL = "${pkgs.zsh}/bin/zsh";

  # Environment Variables and Aliases
  environment.systemPath = ["$HOME/bin"];
  # environment.variables.LANG = "en_UK.UTF-8";
  environment.variables.LANG = "en_US.UTF-8";

  # Makesure there are no duplicate entries in the PATH and put usr paths first.
  environment.extraInit = ''
    typeset -U PATH path  
  '';

  # Used for backwards compatibility, please read the changelog before changing.
  # $ darwin-rebuild changelog
  system.stateVersion = 4;

  # Configure homebrew homebrew
  homebrew = {
    enable = true;
    brewPrefix = "/opt/homebrew/bin";
    taps = [];
    brews = [];
  };

}