From 862cb7a4bad82f7347f495ad3a91df31cad79214 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A1draig=20Brady?= <pbrady@redhat.com>
Date: Wed, 18 Apr 2012 23:27:31 +0100
Subject: [PATCH] support a configurable libvirt injection partition

This is useful if all guest images have the same structure,
and the root partition is not the first partition.

This is also handy to enable inspection in libguestfs,
which can handle disparate and complicated image layouts.

In future we may change to a StrOpt to support
searching by partition label.

Change-Id: Ie94d61bec8fe4b41d6d2d6d3efa9a4364cf027fe

Conflicts:

	nova/virt/libvirt/connection.py
---
 nova/virt/disk/mount.py         |    6 ++++--
 nova/virt/libvirt/connection.py |   12 ++++++++----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/nova/virt/disk/mount.py b/nova/virt/disk/mount.py
index 4fb5dda..11959b2 100644
--- a/nova/virt/disk/mount.py
+++ b/nova/virt/disk/mount.py
@@ -58,7 +58,9 @@ class Mount(object):
         """Map partitions of the device to the file system namespace."""
         assert(os.path.exists(self.device))
 
-        if self.partition:
+        if self.partition == -1:
+            self.error = _('partition search unsupported with %s') % self.mode
+        elif self.partition:
             map_path = '/dev/mapper/%sp%s' % (os.path.basename(self.device),
                                               self.partition)
             assert(not os.path.exists(map_path))
@@ -73,7 +75,7 @@ class Mount(object):
             # so given we only use it when we expect a partitioned image, fail
             if not os.path.exists(map_path):
                 if not err:
-                    err = _('no partitions found')
+                    err = _('partition %s not found') % self.partition
                 self.error = _('Failed to map partitions: %s') % err
             else:
                 self.mapped_device = map_path
diff --git a/nova/virt/libvirt/connection.py b/nova/virt/libvirt/connection.py
index dc16d05..81fd587 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -108,6 +108,11 @@ libvirt_opts = [
     cfg.BoolOpt('libvirt_inject_key',
                 default=True,
                 help='Inject the ssh public key at boot time'),
+    cfg.IntOpt('libvirt_inject_partition',
+                default=1,
+                help='The partition to inject to : '
+                     '-1 => inspect (libguestfs only), 0 => not partitioned, '
+                     '>0 => partition number'),
     cfg.BoolOpt('use_usb_tablet',
                 default=True,
                 help='Sync virtual and real mouse cursors in Windows VMs'),
@@ -1285,12 +1290,11 @@ class LibvirtConnection(driver.ComputeDriver):
                               cow=FLAGS.use_cow_images,
                               swap_mb=swap_mb)
 
-        # For now, we assume that if we're not using a kernel, we're using a
-        # partitioned disk image where the target partition is the first
-        # partition
         target_partition = None
         if not instance['kernel_id']:
-            target_partition = "1"
+            target_partition = FLAGS.libvirt_inject_partition
+            if target_partition == 0:
+                target_partition = None
 
         config_drive_id = instance.get('config_drive_id')
         config_drive = instance.get('config_drive')