From 2b3a1e7e83e00c1fda9cf50e0a67109fbd8e13a7 Mon Sep 17 00:00:00 2001
From: Pádraig Brady <pbrady@redhat.com>
Date: Wed, 18 Apr 2012 23:27:31 +0100
Subject: 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
---
 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 4fb5dda54..11959b2f6 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 96c2b89e0..9592f9e73 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -105,6 +105,11 @@ 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'),
@@ -1253,12 +1258,11 @@ 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')
-- 
cgit