Add backing file format to the output4.12.0

Since libvirt 6, it might be important to understand the
format of the backing image [1] and verify it before operations.

So we adding backing file format to the output of the QemuImgInfo

[1] https://libvirt.org/kbase/backing_chains.html

Change-Id: If83289882e79a973bc77f332408f8f7317351f6f

2 files changed, 19 insertions, 2 deletions

diff --git a/oslo_utils/imageutils.py b/oslo_utils/imageutils.py
index d764a7f..4808091 100644
--- a/oslo_utils/imageutils.py
+++ b/oslo_utils/imageutils.py
@@ -58,6 +58,7 @@ class QemuImgInfo(object):
             details = json.loads(cmd_output or '{}')
             self.image = details.get('filename')
             self.backing_file = details.get('backing-filename')
+            self.backing_file_format = details.get('backing-filename-format')
             self.file_format = details.get('format')
             self.virtual_size = details.get('virtual-size')
             self.cluster_size = details.get('cluster-size')
@@ -75,6 +76,7 @@ class QemuImgInfo(object):
             details = self._parse(cmd_output or '')
             self.image = details.get('image')
             self.backing_file = details.get('backing_file')
+            self.backing_file_format = details.get('backing_file_format')
             self.file_format = details.get('file_format')
             self.virtual_size = details.get('virtual_size')
             self.cluster_size = details.get('cluster_size')
@@ -91,6 +93,7 @@ class QemuImgInfo(object):
             'disk_size: %s' % self.disk_size,
             'cluster_size: %s' % self.cluster_size,
             'backing_file: %s' % self.backing_file,
+            'backing_file_format: %s' % self.backing_file_format,
         ]
         if self.snapshots:
             lines.append("snapshots: %s" % self.snapshots)
diff --git a/oslo_utils/tests/test_imageutils.py b/oslo_utils/tests/test_imageutils.py
index 6b25226..5705ca8 100644
--- a/oslo_utils/tests/test_imageutils.py
+++ b/oslo_utils/tests/test_imageutils.py
@@ -174,6 +174,12 @@ class ImageUtilsHumanQemuTestCase(ImageUtilsHumanRawTestCase):
               exp_backing_file='/b/3a988059e51a_2')),
     ]
 
+    _qcow2_backing_file_format = [
+        ('no_backing_file_format', dict(backing_file_format=None)),
+        ('backing_file_format', dict(backing_file_format='qcow2',
+                                     exp_backing_file_format='qcow2')),
+    ]
+
     @classmethod
     def generate_scenarios(cls):
         cls.scenarios = testscenarios.multiply_scenarios(
@@ -185,7 +191,8 @@ class ImageUtilsHumanQemuTestCase(ImageUtilsHumanRawTestCase):
             cls._snapshot_count,
             cls._qcow2_cluster_size,
             cls._qcow2_encrypted,
-            cls._qcow2_backing_file)
+            cls._qcow2_backing_file,
+            cls._qcow2_backing_file_format)
 
     @mock.patch("debtcollector.deprecate")
     def test_qemu_img_info_human_format(self, mock_deprecate):
@@ -194,6 +201,9 @@ class ImageUtilsHumanQemuTestCase(ImageUtilsHumanRawTestCase):
         if self.backing_file is not None:
             img_info = img_info + ('backing file: %s' %
                                    self.backing_file,)
+            if self.backing_file_format is not None:
+                img_info = img_info + ('backing file format: %s' %
+                                       self.backing_file_format,)
         if self.encrypted is not None:
             img_info = img_info + ('encrypted: %s' % self.encrypted,)
         if self.garbage_before_snapshot is True:
@@ -211,6 +221,9 @@ class ImageUtilsHumanQemuTestCase(ImageUtilsHumanRawTestCase):
         if self.backing_file is not None:
             self.assertEqual(image_info.backing_file,
                              self.exp_backing_file)
+            if self.backing_file_format is not None:
+                self.assertEqual(image_info.backing_file_format,
+                                 self.exp_backing_file_format)
         if self.encrypted is not None:
             self.assertEqual(image_info.encrypted, self.encrypted)
 
@@ -223,7 +236,8 @@ class ImageUtilsBlankTestCase(test_base.BaseTestCase):
         example_output = '\n'.join(['image: None', 'file_format: None',
                                     'virtual_size: None', 'disk_size: None',
                                     'cluster_size: None',
-                                    'backing_file: None'])
+                                    'backing_file: None',
+                                    'backing_file_format: None'])
         image_info = imageutils.QemuImgInfo()
         self.assertEqual(str(image_info), example_output)
         self.assertEqual(len(image_info.snapshots), 0)