Updated code to update attach_time of a volume while detaching

While detaching volume from an instance, attach_time of the
volume is not updated. This task updates volume['attach_time']
to NONE at detach_volume.

Also modified the default value of XML attribute
volume['attach_time'] '-' to ''(a 0 length string) to
maintain consistency with existing code.

Fixes bug: 1056122

Change-Id: If56ceda6caab80fb803fcf194ed1dfb18808ec3a

nova/api/ec2/cloud.py

@@ -978,7 +978,7 @@ def _format_instance_bdm(self, context, instance_uuid, root_device_name,
             # TODO(yamahata): volume attach time
             ebs = {'volumeId': volume_id,
                    'deleteOnTermination': bdm['delete_on_termination'],
-                   'attachTime': vol['attach_time'] or '-',
+                   'attachTime': vol['attach_time'] or '',
                    'status': vol['status'], }
             res = {'deviceName': bdm['device_name'],
                    'ebs': ebs, }

nova/db/sqlalchemy/api.py

@@ -2981,6 +2981,7 @@ def volume_detached(context, volume_id):
         volume_ref['mountpoint'] = None
         volume_ref['attach_status'] = 'detached'
         volume_ref['instance_uuid'] = None
+        volume_ref['attach_time'] = None
         volume_ref.save(session=session)
 
 

nova/tests/api/ec2/test_cloud.py

@@ -2051,12 +2051,14 @@ def _assert_volume_attached(self, vol, instance_uuid, mountpoint):
         self.assertEqual(vol['mountpoint'], mountpoint)
         self.assertEqual(vol['status'], "in-use")
         self.assertEqual(vol['attach_status'], "attached")
+        self.assertNotEqual(vol['attach_time'], None)
 
     def _assert_volume_detached(self, vol):
         self.assertEqual(vol['instance_uuid'], None)
         self.assertEqual(vol['mountpoint'], None)
         self.assertEqual(vol['status'], "available")
         self.assertEqual(vol['attach_status'], "detached")
+        self.assertEqual(vol['attach_time'], None)
 
     def test_stop_start_with_volume(self):
         """Make sure run instance with block device mapping works"""

nova/tests/test_volume.py

@@ -273,6 +273,7 @@ def test_run_attach_detach_volume(self):
         self.assertEqual(vol['attach_status'], "attached")
         self.assertEqual(vol['mountpoint'], mountpoint)
         self.assertEqual(vol['instance_uuid'], instance_uuid)
+        self.assertNotEqual(vol['attach_time'], None)
 
         self.assertRaises(exception.VolumeAttached,
                           self.volume.delete_volume,
@@ -286,6 +287,7 @@ def test_run_attach_detach_volume(self):
                                        volume_id)
         vol = db.volume_get(self.context, volume_id)
         self.assertEqual(vol['status'], "available")
+        self.assertEqual(vol['attach_time'], None)
 
         self.volume.delete_volume(self.context, volume_id)
         self.assertRaises(exception.VolumeNotFound,