Description of problem:

It is not possible to convert glance images

Version-Release number of selected component (if applicable):

14

How reproducible:

Always

Steps to Reproduce:
1. glance image-create-via-import --disk-format qcow2 --container-format bare --name cirros --import-method web-download --uri http://download.cirros-cloud.net/0.4.0/cirros-0.4.0-x86_64-disk.img

2.
3.

Actual results:

Image is not converted (stays in qcow), Glance api logs:

2018-11-28 16:26:46.502 24 INFO eventlet.wsgi.server [-] 172.17.1.201 - - [28/Nov/2018 16:26:46] "GET /healthcheck HTTP/1.0" 200 137 0.003688
2018-11-28 16:26:46.870 25 WARNING glance.async.taskflow_executor [-] Task 'api_image_import-Convert_Image-f8822a30-4980-451d-bbed-d73fd48736a8' (ba9729e1-9069-40fd-a3fd-496072765936) transitioned into state 'FAILURE' from state 'RUNNING'
5 predecessors (most recent first):
  Flow 'api_image_import'
  |__Atom 'api_image_import-ConfigureStaging-f8822a30-4980-451d-bbed-d73fd48736a8' {'intention': 'EXECUTE', 'state': 'SUCCESS', 'requires': {}, 'provides': 'file:///var/lib/glance/staging/7b317981-81a6-4839-8bc3-a138ddb4472d'}
     |__Flow 'api_image_import'
        |__Atom 'api_image_import_retry' {'intention': 'EXECUTE', 'state': 'SUCCESS', 'requires': {}, 'provides': [(None, {})]}
           |__Flow 'api_image_import': NoSuchOptError: no such option conversion_plugin_options in group [DEFAULT]
2018-11-28 16:26:46.870 25 ERROR glance.async.taskflow_executor Traceback (most recent call last):
2018-11-28 16:26:46.870 25 ERROR glance.async.taskflow_executor   File "/usr/lib/python2.7/site-packages/taskflow/engines/action_engine/executor.py", line 53, in _execute_task
2018-11-28 16:26:46.870 25 ERROR glance.async.taskflow_executor     result = task.execute(**arguments)
2018-11-28 16:26:46.870 25 ERROR glance.async.taskflow_executor   File "/usr/lib/python2.7/site-packages/glance/async/flows/plugins/image_conversion.py", line 78, in execute
2018-11-28 16:26:46.870 25 ERROR glance.async.taskflow_executor     target_format = CONF.conversion_plugin_options.output_format
2018-11-28 16:26:46.870 25 ERROR glance.async.taskflow_executor   File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2644, in __getattr__
2018-11-28 16:26:46.870 25 ERROR glance.async.taskflow_executor     raise NoSuchOptError(name)
2018-11-28 16:26:46.870 25 ERROR glance.async.taskflow_executor NoSuchOptError: no such option conversion_plugin_options in group [DEFAULT]


Expected results:

Conversion works

Additional info:

Issue is there http://git.openstack.org/cgit/openstack/glance/tree/glance/async_/flows/plugins/image_conversion.py#n78

CONF.conversion_plugin_options.output_format looks incorrect. Worked around with
target_format = CONF.image_conversion.output_format