From 292827b0e0a52312a1abe67bfc8baa44afd04e27 Mon Sep 17 00:00:00 2001
From: Bjørn Forsman <bjorn.forsman@gmail.com>
Date: Fri, 14 Jul 2017 17:20:58 +0200
Subject: nixos/libvirt: modify xml with xmlstarlet

Instead of grep and sed, which is brittle.

(I don't know how to preserve the comment we currently add to say that
this line is auto-updated. But I don't think it adds much value, so I'm
not spending any effort on it.)
---
 nixos/modules/virtualisation/libvirtd.nix | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/virtualisation/libvirtd.nix b/nixos/modules/virtualisation/libvirtd.nix
index 10a38b99f871..c8742b27c6d5 100644
--- a/nixos/modules/virtualisation/libvirtd.nix
+++ b/nixos/modules/virtualisation/libvirtd.nix
@@ -162,11 +162,11 @@ in {
         for file in /var/lib/libvirt/qemu/*.xml /var/lib/libvirt/lxc/*.xml; do
             test -f "$file" || continue
             # get (old) emulator path from config file
-            emulator=$(grep "^[[:space:]]*<emulator>" "$file" | sed 's,^[[:space:]]*<emulator>\(.*\)</emulator>.*,\1,')
+            emulator=$("${pkgs.xmlstarlet}/bin/xmlstarlet" select --template --value-of "/domain/devices/emulator" "$file")
             # get a (definitely) working emulator path by re-scanning $PATH
             new_emulator=$(PATH=${pkgs.libvirt}/libexec:$PATH command -v $(basename "$emulator"))
             # write back
-            sed -i "s,^[[:space:]]*<emulator>.*,    <emulator>$new_emulator</emulator> <!-- WARNING: emulator dirname is auto-updated by the nixos libvirtd module -->," "$file"
+            "${pkgs.xmlstarlet}/bin/xmlstarlet" edit --inplace --update "/domain/devices/emulator" -v "$new_emulator" "$file"
         done
       ''; # */
 
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cgit 1.4.1