configuration.nix to use for fresh installs of NixOS 21.05 (enables flakes and sets some standard options for grub/UEFI)

configuration.nix

{ config, pkgs, ... }:
let
  grubOptions = {
    boot.loader.grub.enable = true;
    boot.loader.grub.version = 2;
    boot.loader.grub.device = "/dev/vda";
  };
  uefiOptions = {
    boot.loader.systemd-boot.enable = true;
    boot.loader.efi.canTouchEfiVariables = true;
    boot.loader.timeout = 2;
  };
in
{
  imports = [
    ./hardware-configuration.nix
  ];

  environment.systemPackages = [
    pkgs.git
    pkgs.vim
  ];

  nix = {
    package = pkgs.nixUnstable;
    extraOptions = "experimental-features = nix-command flakes";
  };

  system.stateVersion = "21.05";
} // grubOptions # can be changed to uefiOptions