Session startup commands

  services = {
    openssh.enable = true;
    udisks2.enable = true;
    xserver = {
      enable = true;

      displayManager.sessionCommands = with pkgs; lib.mkAfter ''
        ${xlibs.xsetroot}/bin/xsetroot -cursor_name left_ptr ;
        ${networkmanagerapplet}/bin/nm-applet &
        ${dunst}/bin/dunst -fn "PxPlus IBM VGA9 16px" -lb "#000000" -nb "#000000" -cb "#000000" -lf "#00ff00" -nf "#ffff00" -cf "#ff0000" -to 3 &
        ${udiskie}/bin/udiskie &
        ${xss-lock}/bin/xss-lock -- i3lock -n -c 000000 &
        exec ${i3}/bin/i3
      '';

      synaptics.enable = true;
    };
  };