From 3c6eb3a247721aafded88c789d247602762b7d86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Forsman?= <bjorn.forsman@gmail.com>
Date: Tue, 26 Sep 2017 22:17:01 +0200
Subject: [PATCH] nixos/iso-image.nix: add top-level /version.txt file

This makes it easy to identify which NixOS version is written to an USB
stick without actually booting it.
---
 nixos/modules/installer/cd-dvd/iso-image.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/nixos/modules/installer/cd-dvd/iso-image.nix b/nixos/modules/installer/cd-dvd/iso-image.nix
index 96f7aac1d59..a039f7fdcb6 100644
--- a/nixos/modules/installer/cd-dvd/iso-image.nix
+++ b/nixos/modules/installer/cd-dvd/iso-image.nix
@@ -361,6 +361,9 @@ in
         { source = config.isoImage.splashImage;
           target = "/isolinux/background.png";
         }
+        { source = pkgs.writeText "version" config.system.nixosVersion;
+          target = "/version.txt";
+        }
       ] ++ optionals config.isoImage.makeEfiBootable [
         { source = efiImg;
           target = "/boot/efi.img";