From 37c17d760129be116cca67661acc947ce43be522 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Mon, 18 Dec 2006 16:27:56 +0000
Subject: [PATCH] * When runtime switching to a new configuration,
 stop/start/restart   Upstart jobs as appropriate.  I.e., if a job exists in
 the old but   not the new configuration, stop it; if it exists in the new but
 not   the old, start it; and most interesting, if it exists in both but   its
 store paths differ, restart it.  So the purely functional model   combined
 cryptographic hashing allows us to precisely identify how   two
 configurations differ from each other

svn path=/nixos/trunk/; revision=7385
---
 configuration/switch-to-configuration.sh | 39 ++++++++++++++++++++++--
 configuration/system.nix                 |  9 +++++-
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/configuration/switch-to-configuration.sh b/configuration/switch-to-configuration.sh
index faf592834d9..11a5ccb5367 100644
--- a/configuration/switch-to-configuration.sh
+++ b/configuration/switch-to-configuration.sh
@@ -2,7 +2,7 @@
 
 set -e
 export PATH=/empty
-for i in @path@; do PATH=$PATH:$i/bin; done
+for i in @path@; do PATH=$PATH:$i/bin:$i/sbin; done
 action="$1"
 
 if ! test -e /etc/NIXOS; then
@@ -34,9 +34,44 @@ if test "$action" = "switch" -o "$action" = "boot"; then
 fi
 
 if test "$action" = "switch" -o "$action" = "test"; then
+
+    oldEvents=$(readlink -f /etc/event.d || true)
+    newEvents=$(readlink -f @out@/etc/event.d)
+
+    echo "old: $oldEvents"
+    echo "new: $newEvents"
+
+    # Stop all services that are not in the new Upstart
+    # configuration.
+    for event in $(cd $oldEvents && ls); do
+        if ! test -e "$newEvents/$event"; then
+            echo "stopping $event..."
+            initctl stop "$event"
+        fi
+    done
+
+    # Activate the new configuration (i.e., update /etc, make
+    # accounts, and so on).
     echo "Activating the configuration..."
     @out@/activate
-    kill -TERM 1 # make Upstart reload its events    
+
+    # Make Upstart reload its events.  !!! Should wait until it has
+    # finished processing its stop events.
+    kill -TERM 1 
+
+    # Start all new services and restart all changed services.
+    for event in $(cd $newEvents && ls); do
+        if ! test -e "$oldEvents/$event"; then
+            echo "starting $event..."
+            initctl start "$event"
+        elif test "$(readlink "$oldEvents/$event")" != "$(readlink "$newEvents/$event")"; then
+            echo "restarting $event..."
+            initctl stop "$event"
+            initctl start "$event"
+        else
+            echo "unchanged $event"
+        fi
+    done
 fi
 
 sync
diff --git a/configuration/system.nix b/configuration/system.nix
index a78708e8e4a..5a91c38e95b 100644
--- a/configuration/system.nix
+++ b/configuration/system.nix
@@ -242,7 +242,14 @@ rec {
     kernel = pkgs.kernel + "/vmlinuz";
     initrd = initialRamdisk + "/initrd";
     # Most of these are needed by grub-install.
-    path = [pkgs.coreutils pkgs.gnused pkgs.gnugrep pkgs.findutils pkgs.diffutils];
+    path = [
+      pkgs.coreutils
+      pkgs.gnused
+      pkgs.gnugrep
+      pkgs.findutils
+      pkgs.diffutils
+      pkgs.upstart # for initctl
+    ];
   };