From cda2e41c017f68f0f4a522d8c5b039ec86e05b92 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Wed, 6 Oct 2010 16:07:16 +0000
Subject: [PATCH] * Added a "xendomains" job to automatically start the domains
 defined   in /etc/xen/auto at boot time, to save all running domains during  
 shutdown, and to restore all saved domains at boot time.

svn path=/nixos/trunk/; revision=24121
---
 .../activation/switch-to-configuration.sh     |  6 +++-
 modules/virtualisation/xen-dom0.nix           | 30 ++++++++++++++++++-
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/modules/system/activation/switch-to-configuration.sh b/modules/system/activation/switch-to-configuration.sh
index ffc9845622c..3249ee3ea34 100644
--- a/modules/system/activation/switch-to-configuration.sh
+++ b/modules/system/activation/switch-to-configuration.sh
@@ -110,7 +110,11 @@ EOF
         # forget about current sessions.
         # Idem for the emergeny-shell, because its `console owner'
         # line screws up the X server.
-        if echo "$job" | grep -q "^shutdown$\|^control-alt-delete$\|^xserver$\|^dbus$\|^disnix$\|^emergency-shell$"; then continue; fi
+        # Idem for xendomains because we don't want to save/restore
+	# Xen domains unless we have to.
+        # TODO: Jobs should be able to declare that they should not be
+	# auto-restarted.
+        if echo "$job" | grep -q "^shutdown$\|^control-alt-delete$\|^xserver$\|^dbus$\|^disnix$\|^emergency-shell$\|^xendomains$"; then continue; fi
 
         if ! test -e "$oldJobs/$job.conf"; then
             echo "starting $job..."
diff --git a/modules/virtualisation/xen-dom0.nix b/modules/virtualisation/xen-dom0.nix
index 65158bc5f81..e10713466f7 100644
--- a/modules/virtualisation/xen-dom0.nix
+++ b/modules/virtualisation/xen-dom0.nix
@@ -108,11 +108,39 @@ in
             pkgs.utillinux pkgs.bash xen pkgs.pciutils pkgs.procps
           ];
 
-        preStart = "${xen}/sbin/xend start";
+        preStart = 
+          ''
+            ${xen}/sbin/xend start
+  
+            # Wait until Xend is running.
+            for ((i = 0; i < 60; i++)); do echo "waiting for xend..."; ${xen}/sbin/xend status && break; done
+
+            ${xen}/sbin/xend status || exit 1
+          '';
 
         postStop = "${xen}/sbin/xend stop";
       };
 
+    jobs.xendomains =
+      { description = "Automatically starts, saves and restores Xen domains on startup/shutdown";
+
+        startOn = "started xend";
+
+        stopOn = "starting shutdown and stopping xend";
+
+        path = [ pkgs.xen ];
+
+        environment.XENDOM_CONFIG = "${xen}/etc/sysconfig/xendomains";
+
+        preStart = 
+          ''
+            mkdir -p /var/lock/subsys -m 755
+            ${xen}/etc/init.d/xendomains start
+          '';
+
+        postStop = "${xen}/etc/init.d/xendomains stop";
+      };
+
     # To prevent a race between dhclient and xend's bridge setup
     # script (which renames eth* to peth* and recreates eth* as a
     # virtual device), start dhclient after xend.