From ae40ceba8420b3b6c4bd8e29cf95ec21fd20e1e8 Mon Sep 17 00:00:00 2001
From: Takashi NATSUME <natsume.takashi@lab.ntt.co.jp>
Date: Sat, 23 Feb 2019 00:56:23 +0900
Subject: [PATCH] Override the 'get' method in DriverBlockDevice class

The following methods are overridden in DriverBlockDevice class.

* __getattr__
* __getitem__

The 'get' method is not overridden.
The value cannot be got by the 'get' method
though the value can be got by '__getattr__' (e.g. bdm.volumd_id)
or '__getitem__' (e.g. bdm['volume_id']) method.
So override the 'get' method to fix the issue.

Change-Id: Ic665fc1956831110937d98553e526cb909e49997
Closes-Bug: #1816938
(cherry picked from commit 3c66b40dbd23e3f792a86da5a15c993c52c9b377)
---
 nova/tests/unit/virt/test_block_device.py | 7 +++++--
 nova/virt/block_device.py                 | 8 ++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/nova/tests/unit/virt/test_block_device.py b/nova/tests/unit/virt/test_block_device.py
index d4085bc71d84..9eb7d9ce8ead 100644
--- a/nova/tests/unit/virt/test_block_device.py
+++ b/nova/tests/unit/virt/test_block_device.py
@@ -191,7 +191,6 @@ class TestDriverBlockDevice(test.NoDBTestCase):
          'destination_type': 'volume',
          'connection_info': '{"fake": "connection_info"}',
          'snapshot_id': 'fake-snapshot-id-1',
-         'volume_id': 'fake-volume-id-2',
          'boot_index': -1,
          'volume_type': None})
 
@@ -379,6 +378,7 @@ class TestDriverBlockDevice(test.NoDBTestCase):
         self.assertEqual(test_bdm._bdm_obj.id, 3)
         self.assertEqual(test_bdm.volume_id, 'fake-volume-id-1')
         self.assertEqual(test_bdm.volume_size, 8)
+        self.assertEqual('fake-volume-id-1', test_bdm.get('volume_id'))
 
     def test_driver_snapshot_block_device(self):
         self._test_driver_device("volsnapshot")
@@ -389,6 +389,7 @@ class TestDriverBlockDevice(test.NoDBTestCase):
         self.assertEqual(test_bdm.snapshot_id, 'fake-snapshot-id-1')
         self.assertEqual(test_bdm.volume_id, 'fake-volume-id-2')
         self.assertEqual(test_bdm.volume_size, 3)
+        self.assertEqual('fake-snapshot-id-1', test_bdm.get('snapshot_id'))
 
     def test_driver_image_block_device(self):
         self._test_driver_device('volimage')
@@ -398,6 +399,7 @@ class TestDriverBlockDevice(test.NoDBTestCase):
         self.assertEqual(test_bdm._bdm_obj.id, 5)
         self.assertEqual(test_bdm.image_id, 'fake-image-id-1')
         self.assertEqual(test_bdm.volume_size, 1)
+        self.assertEqual('fake-image-id-1', test_bdm.get('image_id'))
 
     def test_driver_image_block_device_destination_local(self):
         self._test_driver_device('volimage')
@@ -413,8 +415,9 @@ class TestDriverBlockDevice(test.NoDBTestCase):
         test_bdm = self.driver_classes['volblank'](
             self.volblank_bdm)
         self.assertEqual(6, test_bdm._bdm_obj.id)
-        self.assertEqual('fake-volume-id-2', test_bdm.volume_id)
+        self.assertIsNone(test_bdm.volume_id)
         self.assertEqual(3, test_bdm.volume_size)
+        self.assertIsNone(test_bdm.get('volume_id'))
 
     def _test_call_wait_func(self, delete_on_termination, delete_fail=False):
         test_bdm = self.driver_classes['volume'](self.volume_bdm)
diff --git a/nova/virt/block_device.py b/nova/virt/block_device.py
index 8abbdb40f2b0..236025596755 100644
--- a/nova/virt/block_device.py
+++ b/nova/virt/block_device.py
@@ -171,6 +171,14 @@ class DriverBlockDevice(dict):
         """Transform bdm to the format that is passed to drivers."""
         raise NotImplementedError()
 
+    def get(self, name, default=None):
+        if name in self._proxy_as_attr:
+            return getattr(self._bdm_obj, name)
+        elif name in self._fields:
+            return self[name]
+        else:
+            return super(DriverBlockDevice, self).get(name, default)
+
     def legacy(self):
         """Basic legacy transformation.