Libvirt driver reports incorrect error when volume-detach fails

[Aaron Rosen]

Same as https://bugs.launchpad.net/nova/+bug/1029463 but in essex.

 stderr= from (pid=23826) _run_iscsiadm /usr/lib/python2.7/dist-packages/nova/virt/libvirt/volume.py:112
2012-08-22 09:15:20 DEBUG nova.utils [req-c7892a94-99f8-432c-a28e-59bfde9fc95b jcherkas att] Running cmd (subprocess): sudo nova-rootwrap iscsiadm -m node -T iqn.2010-10.org.openstack:volume-000000c4 -p 10.34.65.24:3260 --op delete from (pid=23826) execute /usr/lib/python2.7/dist-packages/nova/utils.py:219
2012-08-22 09:15:20 DEBUG nova.virt.libvirt.volume [req-c7892a94-99f8-432c-a28e-59bfde9fc95b jcherkas att] iscsiadm ('--op', 'delete'): stdout= stderr= from (pid=23826) _run_iscsiadm /usr/lib/python2.7/dist-packages/nova/virt/libvirt/volume.py:112
2012-08-22 09:15:20 ERROR nova.compute.manager [req-c7892a94-99f8-432c-a28e-59bfde9fc95b jcherkas att] [instance: 35176728-876f-40f8-9643-c04d94608250] Attach failed /dev/vdb, removing
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250] Traceback (most recent call last):
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250] File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 1727, in attach_volume
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250] mountpoint)
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250] File "/usr/lib/python2.7/dist-packages/nova/exception.py", line 114, in wrapped
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250] return f(*args, **kw)
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250] File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/connection.py", line 546, in attach_volume
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250] raise
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250] TypeError: exceptions must be old-style classes or derived from BaseException, not NoneType
2012-08-22 09:15:20 TRACE nova.compute.manager [instance: 35176728-876f-40f8-9643-c04d94608250]
2012-08-22 09:15:20 DEBUG nova.rpc.amqp [req-c7892a94-99f8-432c-a28e-59bfde9fc95b jcherkas att] Making asynchronous call on volume.cs-srv17 ... from (pid=23826) multicall /usr/lib/python2.7/dist-packages/nova/rpc/amqp.py:326
2012-08-22 09:15:20 DEBUG nova.rpc.amqp [req-c7892a94-99f8-432c-a28e-59bfde9fc95b jcherkas att] MSG_ID is 65d45c7e60d74470ba94422342231f64 from (pid=23826) multicall /usr/lib/python2.7/dist-packages/nova/rpc/amqp.py:329
2012-08-22 09:15:20 ERROR nova.rpc.amqp [req-c7892a94-99f8-432c-a28e-59bfde9fc95b jcherkas att] Exception during message handling
2012-08-22 09:15:20 TRACE nova.rpc.amqp Traceback (most recent call last):
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/rpc/amqp.py", line 253, in _process_data
2012-08-22 09:15:20 TRACE nova.rpc.amqp rval = node_func(context=ctxt, **node_args)
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/exception.py", line 114, in wrapped
2012-08-22 09:15:20 TRACE nova.rpc.amqp return f(*args, **kw)
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 159, in decorated_function
2012-08-22 09:15:20 TRACE nova.rpc.amqp function(self, context, instance_uuid, *args, **kwargs)
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 183, in decorated_function
2012-08-22 09:15:20 TRACE nova.rpc.amqp sys.exc_info())
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/contextlib.py", line 24, in __exit__
2012-08-22 09:15:20 TRACE nova.rpc.amqp self.gen.next()
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 177, in decorated_function
2012-08-22 09:15:20 TRACE nova.rpc.amqp return function(self, context, instance_uuid, *args, **kwargs)
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 1735, in attach_volume
2012-08-22 09:15:20 TRACE nova.rpc.amqp connector)
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/contextlib.py", line 24, in __exit__
2012-08-22 09:15:20 TRACE nova.rpc.amqp self.gen.next()
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 1727, in attach_volume
2012-08-22 09:15:20 TRACE nova.rpc.amqp mountpoint)
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/exception.py", line 114, in wrapped
2012-08-22 09:15:20 TRACE nova.rpc.amqp return f(*args, **kw)
2012-08-22 09:15:20 TRACE nova.rpc.amqp File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/connection.py", line 546, in attach_volume
2012-08-22 09:15:20 TRACE nova.rpc.amqp raise
2012-08-22 09:15:20 TRACE nova.rpc.amqp TypeError: exceptions must be old-style classes or derived from BaseException, not NoneType

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/essex
Review: https://review.openstack.org/11809

[Mark McLoughlin (markmc)]

The right way to do this is to target bug #1029463 to essex