my nix configuration

configuration.nix

# Edit this configuration file to define what should be installed on
# your system.  Help is available in the configuration.nix(5) man page
# and in the NixOS manual (accessible by running ‘nixos-help’).

{ config, pkgs, ... }:

{
  imports =
    [ # Include the results of the hardware scan.
      ./hardware-configuration.nix
    ];

  #
  # Use the systemd-boot EFI boot loader.
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;

  # Automatic Updates
  system.autoUpgrade.enable = true;
  system.autoUpgrade.channel = "https://nixos.org/channels/nixos-19.03";

  networking.hostName = "vonBaellchen"; # Define your hostname.
  # networking.wireless.enable = true;  # Enables wireless support via wpa_supplicant.
 
  # Network manager
  networking.networkmanager.enable = true;

  # Configure network proxy if necessary
  # networking.proxy.default = "http://user:password@proxy:port/";
  # networking.proxy.noProxy = "127.0.0.1,localhost,internal.domain";

  # Select internationalisation properties.
  i18n = {
    consoleFont = "Lat2-Terminus16";
    consoleKeyMap = "de";
    defaultLocale = "en_US.UTF-8";
  };

  # Set your time zone.
  time.timeZone = "Europe/Amsterdam";

  # List packages installed in system profile. To search, run:
  # $ nix search wget
  environment.systemPackages = with pkgs; [
    curl
    wget
    vim
    nano
    tmux
    git
    ffmpeg
    zlib
    binutils
    sublime
    jetbrains.idea-community
    gnome3.gnome-terminal
    gnomeExtensions.dash-to-dock
    gnomeExtensions.nohotcorner
    firefox
    dropbox-cli
    pidgin
    irssi
    steam
    skypeforlinux
    rustup
    exercism
    jdk11
    maven
    gcc
    elixir
    python37Packages.pip
    python3
    (python37.withPackages(ps: with ps; [ virtualenv ]))
    ruby
    multimc
    discord
    libsForQt5.vlc
  ];

  # Sublime Text 3 is unfree
  nixpkgs.config.allowUnfree = true;

  # Some programs need SUID wrappers, can be configured further or are
  # started in user sessions.
  # programs.mtr.enable = true;
  # programs.gnupg.agent = { enable = true; enableSSHSupport = true; };

  # List services that you want to enable:

  # Enable the OpenSSH daemon.
  # services.openssh.enable = true;

  # Open ports in the firewall.
  # networking.firewall.allowedTCPPorts = [ ... ];
  # networking.firewall.allowedUDPPorts = [ ... ];
  # Or disable the firewall altogether.
  # networking.firewall.enable = false;

  # Enable CUPS to print documents.
  # services.printing.enable = true;

  # Enable sound.
  sound.enable = true;
  hardware.pulseaudio.enable = true;

  boot.extraModprobeConfig = ''
    options snd slots=snd-hda-intel
  '';

  # Enable the X11 windowing system.
  services.xserver.enable = true;
  services.xserver.layout = "de";
  services.xserver.xkbOptions = "eurosign:e";

  # Enable touchpad support.
  services.xserver.libinput.enable = true;

  # Enable the KDE Desktop Environment.
  # services.xserver.displayManager.sddm.enable = true;
  # services.xserver.desktopManager.plasma5.enable = true;

  # GNOME
  services.xserver.displayManager.gdm.enable = true;
  services.xserver.desktopManager.gnome3.enable = true;

  # MATE
  # services.xserver.displayManager.gdm.enable = true;
  # services.xserver.desktopManager.mate.enable = true;

  hardware.opengl = {
    enable = true;
    extraPackages = with pkgs; [
      vaapiIntel
      vaapiVdpau
      libvdpau-va-gl
    ];
    driSupport32Bit = true;
  };

  # Define a user account. Don't forget to set a password with ‘passwd’.
  users.users.iser = {
    isNormalUser = true;
    extraGroups = [ "wheel" ]; # Enable ‘sudo’ for the user.
  };

  # This value determines the NixOS release with which your system is to be
  # compatible, in order to avoid breaking some software such as database
  # servers. You should change this only after NixOS release notes say you
  # should.
  system.stateVersion = "19.09"; # Did you read the comment?

}