Move to a more canonicalized output from qemu-img info.

Move to a form that is all lower cased, dashes->underscores, underscores
instead of spaces which allows for better integration with python. Also
make the parser more robust to failures when encountering new fields such
as snapshot lists. Provide a new qemu img info object that can be used
to do the parsing and access the underlying attributes.

Change-Id: Ie098dbd9f06dd4ef966768e2caa128f1d09b019c

2 files changed, 118 insertions, 17 deletions

diff --git a/nova/tests/test_image_utils.py b/nova/tests/test_image_utils.py
index 711f1c202..fac0422bf 100644
--- a/nova/tests/test_image_utils.py
+++ b/nova/tests/test_image_utils.py
@@ -21,7 +21,7 @@ from nova.virt import images
 
 
 class ImageUtilsTestCase(test.TestCase):
-    def test_qemu_info(self):
+    def test_qemu_info_canon(self):
         path = "disk.config"
         example_output = """image: disk.config
 file format: raw
@@ -35,14 +35,35 @@ blah BLAH: bb
                       'qemu-img', 'info', path).AndReturn((example_output, ''))
         self.mox.ReplayAll()
         image_info = images.qemu_img_info(path)
-        self.assertEquals('disk.config', image_info['image'])
-        self.assertEquals('raw', image_info['file format'])
-        self.assertEquals('64M (67108864 bytes)', image_info['virtual size'])
-        self.assertEquals('96K', image_info['disk size'])
-        self.assertEquals('bb', image_info['blah blah'])
-        self.assertEquals("65536", image_info['cluster_size'])
+        self.assertEquals('disk.config', image_info.image)
+        self.assertEquals('raw', image_info.file_format)
+        self.assertEquals(67108864, image_info.virtual_size)
+        self.assertEquals(98304, image_info.disk_size)
+        self.assertEquals(65536, image_info.cluster_size)
 
-    def test_qemu_info_snap(self):
+    def test_qemu_info_canon2(self):
+        path = "disk.config"
+        example_output = """image: disk.config
+file format: QCOW2
+virtual size: 67108844
+cluster_size: 65536
+disk size: 963434
+backing file: /var/lib/nova/a328c7998805951a_2
+"""
+        self.mox.StubOutWithMock(utils, 'execute')
+        utils.execute('env', 'LC_ALL=C', 'LANG=C',
+                      'qemu-img', 'info', path).AndReturn((example_output, ''))
+        self.mox.ReplayAll()
+        image_info = images.qemu_img_info(path)
+        self.assertEquals('disk.config', image_info.image)
+        self.assertEquals('qcow2', image_info.file_format)
+        self.assertEquals(67108844, image_info.virtual_size)
+        self.assertEquals(963434, image_info.disk_size)
+        self.assertEquals(65536, image_info.cluster_size)
+        self.assertEquals('/var/lib/nova/a328c7998805951a_2',
+                          image_info.backing_file)
+
+    def test_qemu_backing_file_actual(self):
         path = "disk.config"
         example_output = """image: disk.config
 file format: raw
@@ -52,18 +73,63 @@ disk size: 96K
 Snapshot list:
 ID        TAG                 VM SIZE                DATE       VM CLOCK
 1     d9a9784a500742a7bb95627bb3aace38      0 2012-08-20 10:52:46 00:00:00.000
+backing file: /var/lib/nova/a328c7998805951a_2 (actual path: /b/3a988059e51a_2)
+"""
+        self.mox.StubOutWithMock(utils, 'execute')
+        utils.execute('env', 'LC_ALL=C', 'LANG=C',
+                      'qemu-img', 'info', path).AndReturn((example_output, ''))
+        self.mox.ReplayAll()
+        image_info = images.qemu_img_info(path)
+        self.assertEquals('disk.config', image_info.image)
+        self.assertEquals('raw', image_info.file_format)
+        self.assertEquals(67108864, image_info.virtual_size)
+        self.assertEquals(98304, image_info.disk_size)
+        self.assertEquals(1, len(image_info.snapshots))
+        self.assertEquals('/b/3a988059e51a_2',
+                          image_info.backing_file)
+
+    def test_qemu_info_convert(self):
+        path = "disk.config"
+        example_output = """image: disk.config
+file format: raw
+virtual size: 64M
+disk size: 96K
+Snapshot list:
+ID        TAG                 VM SIZE                DATE       VM CLOCK
+1        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
+3        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
+4        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
+junk stuff: bbb
+"""
+        self.mox.StubOutWithMock(utils, 'execute')
+        utils.execute('env', 'LC_ALL=C', 'LANG=C',
+                      'qemu-img', 'info', path).AndReturn((example_output, ''))
+        self.mox.ReplayAll()
+        image_info = images.qemu_img_info(path)
+        self.assertEquals('disk.config', image_info.image)
+        self.assertEquals('raw', image_info.file_format)
+        self.assertEquals(67108864, image_info.virtual_size)
+        self.assertEquals(98304, image_info.disk_size)
+
+    def test_qemu_info_snaps(self):
+        path = "disk.config"
+        example_output = """image: disk.config
+file format: raw
+virtual size: 64M (67108864 bytes)
+disk size: 96K
+Snapshot list:
+ID        TAG                 VM SIZE                DATE       VM CLOCK
+1        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
+3        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
+4        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
 """
         self.mox.StubOutWithMock(utils, 'execute')
         utils.execute('env', 'LC_ALL=C', 'LANG=C',
                       'qemu-img', 'info', path).AndReturn((example_output, ''))
         self.mox.ReplayAll()
         image_info = images.qemu_img_info(path)
-        self.assertEquals('disk.config', image_info['image'])
-        self.assertEquals('raw', image_info['file format'])
-        self.assertEquals('64M (67108864 bytes)', image_info['virtual size'])
-        self.assertEquals('96K', image_info['disk size'])
-        self.assertEquals("65536", image_info['cluster_size'])
-        # This would be triggered if the split encountered this section
-        self.assertNotIn('snapshot list', image_info)
-        bad_cap = '1     d9a9784a500742a7bb95627bb3aace38      0 2012-08-20 10'
-        self.assertNotIn(bad_cap, image_info)
+        self.assertEquals('disk.config', image_info.image)
+        self.assertEquals('raw', image_info.file_format)
+        self.assertEquals(67108864, image_info.virtual_size)
+        self.assertEquals(98304, image_info.disk_size)
+        self.assertEquals(3, len(image_info.snapshots))
diff --git a/nova/tests/test_utils.py b/nova/tests/test_utils.py
index f97d6eeb7..1b84b858d 100644
--- a/nova/tests/test_utils.py
+++ b/nova/tests/test_utils.py
@@ -37,6 +37,41 @@ from nova import utils
 FLAGS = flags.FLAGS
 
 
+class ByteConversionTest(test.TestCase):
+    def test_string_conversions(self):
+        working_examples = {
+            '1024KB': 1048576,
+            '1024TB': 1125899906842624,
+            '1024K': 1048576,
+            '1024T': 1125899906842624,
+            '1TB': 1099511627776,
+            '1T': 1099511627776,
+            '1KB': 1024,
+            '1K': 1024,
+            '1B': 1,
+            '1B': 1,
+            '1': 1,
+            '1MB': 1048576,
+            '7MB': 7340032,
+            '0MB': 0,
+            '0KB': 0,
+            '0TB': 0,
+            '': 0,
+        }
+        for (in_value, expected_value) in working_examples.items():
+            b_value = utils.to_bytes(in_value)
+            self.assertEquals(expected_value, b_value)
+            if len(in_value):
+                in_value = "-" + in_value
+                b_value = utils.to_bytes(in_value)
+                self.assertEquals(expected_value * -1, b_value)
+        breaking_examples = [
+            'junk1KB', '1023BBBB',
+        ]
+        for v in breaking_examples:
+            self.assertRaises(TypeError, utils.to_bytes, v)
+
+
 class ExecuteTestCase(test.TestCase):
     def test_retry_on_failure(self):
         fd, tmpfilename = tempfile.mkstemp()