From 4ff347fe6329e651bc0f72e6a1b95b74b2411781 Mon Sep 17 00:00:00 2001
From: Mikhail Klementev <blame@dumpstack.io>
Date: Fri, 12 Apr 2019 17:24:45 +0000
Subject: [PATCH] Auto reboot after kernel changed

---
 configuration.nix | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/configuration.nix b/configuration.nix
index 8d5a34b..365a957 100644
--- a/configuration.nix
+++ b/configuration.nix
@@ -50,6 +50,18 @@ in {
     };
   };
 
+  systemd.services.nixos-upgrade.serviceConfig.ExecStartPost = pkgs.writeScript "post-upgrade-check" ''
+    #!${pkgs.stdenv.shell}
+    current=$(readlink -f /run/current-system/kernel)
+    booted=$(readlink -f /run/booted-system/kernel)
+    if [ "$current" != "$booted" ]; then
+      echo "kernel changed, reboot" | systemd-cat --identifier "post-upgrade-check";
+      reboot
+    else
+      echo "same kernel, do not reboot" | systemd-cat --identifier "post-upgrade-check";
+    fi
+  '';
+
   system.stateVersion = "18.09";
   system.autoUpgrade.enable = true;
 }