Fixes snapshot instance failure on libvirt.

Fixed the failure during snapshotting instance (on libvirt) due to incorrect
attribute access.

Fixes LP: #1075556

Change-Id: I079467d38aef5071488084f9bfa080a2a5af2609

nova/tests/test_libvirt_utils.py

@@ -0,0 +1,38 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+#
+# Copyright 2012 NTT Data
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from nova import test
+from nova import utils
+from nova.virt.libvirt import utils as libvirt_utils
+
+
+class LibvirtUtilsTestCase(test.TestCase):
+    def test_get_disk_type(self):
+        path = "disk.config"
+        example_output = """image: disk.config
+file format: raw
+virtual size: 64M (67108864 bytes)
+cluster_size: 65536
+disk size: 96K
+blah BLAH: bb
+"""
+        self.mox.StubOutWithMock(utils, 'execute')
+        utils.execute('env', 'LC_ALL=C', 'LANG=C',
+                      'qemu-img', 'info', path).AndReturn((example_output, ''))
+        self.mox.ReplayAll()
+        disk_type = libvirt_utils.get_disk_type(path)
+        self.assertEqual(disk_type, 'raw')

nova/virt/libvirt/utils.py

@@ -414,7 +414,7 @@ def get_disk_type(path):
     if path.startswith('/dev'):
         return 'lvm'
 
-    return images.qemu_img_info(path)['file format']
+    return images.qemu_img_info(path).file_format
 
 
 def get_fs_info(path):