Fix root UUID for streamed partition images

The root UUID changes after a streamed partition image is written to
the block device, causing later deployment failure when assuming the
old UUID.

This change updates the root UUID after streaming the partition image
is complete.

This issue may have been missed in local testing because deploying the
same image repeatedly will result in stable root UUID across runs.

Change-Id: Ice4630c16fc216980488d1427f3b02e1b8a417fa

ironic_python_agent/extensions/standby.py

@@ -600,6 +600,10 @@ class StandbyExtension(base.BaseAgentExtension):
         except exception.InstanceDeployFailure:
             # Note: the catch internal to the helper method logs any errors.
             pass
+        # Fix the root partition UUID
+        root_uuid = disk_utils.block_uuid(device)
+        LOG.info("{} UUID is now {}".format(device, root_uuid))
+        self.partition_uuids['root uuid'] = root_uuid
 
     def _fix_up_partition_uuids(self, image_info, device):
         if self.partition_uuids is None:

ironic_python_agent/tests/unit/extensions/test_standby.py

@@ -1169,12 +1169,14 @@ class TestStandbyExtension(base.IronicAgentTest):
         download_mock.assert_called_once_with(image_info)
         write_mock.assert_called_once_with(image_info, device)
 
+    @mock.patch('ironic_lib.disk_utils.block_uuid', autospec=True)
     @mock.patch('ironic_lib.disk_utils.fix_gpt_partition', autospec=True)
     @mock.patch('hashlib.md5', autospec=True)
     @mock.patch('builtins.open', autospec=True)
     @mock.patch('requests.get', autospec=True)
     def test_stream_raw_image_onto_device(self, requests_mock, open_mock,
-                                          md5_mock, fix_gpt_mock):
+                                          md5_mock, fix_gpt_mock,
+                                          block_uuid_mock):
         image_info = _build_fake_image_info()
         response = requests_mock.return_value
         response.status_code = 200
@@ -1184,6 +1186,9 @@ class TestStandbyExtension(base.IronicAgentTest):
         file_mock.read.return_value = None
         hexdigest_mock = md5_mock.return_value.hexdigest
         hexdigest_mock.return_value = image_info['checksum']
+        self.agent_extension.partition_uuids = {}
+
+        block_uuid_mock.return_value = 'aaaabbbb'
 
         self.agent_extension._stream_raw_image_onto_device(image_info,
                                                            '/dev/foo')
@@ -1194,6 +1199,11 @@ class TestStandbyExtension(base.IronicAgentTest):
         expected_calls = [mock.call('some'), mock.call('content')]
         file_mock.write.assert_has_calls(expected_calls)
         fix_gpt_mock.assert_called_once_with('/dev/foo', node_uuid=None)
+        block_uuid_mock.assert_called_once_with('/dev/foo')
+        self.assertEqual(
+            'aaaabbbb',
+            self.agent_extension.partition_uuids['root uuid']
+        )
 
     @mock.patch('hashlib.md5', autospec=True)
     @mock.patch('builtins.open', autospec=True)

releasenotes/notes/streaming-uuid-fdf136a7745fbb3d.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixes incorrect root partition UUID after streaming a raw partition
+    image.