500 response for incorrect node_staging_uri in glance-api.conf

[Abhishek Kekane]

node_staging_uri configuration option needs a value which always starts with file:///<path>.
If by mistake operator sets value of node_staging_uri without file:/// then import api fails with 500 internal server error.

Steps to reproduce:
1. set below value to node_staging_uri in glance.api.conf
   node_staging_uri = /opt/stack/data/glance/staging
2. Restart glance-api service
3. Import image using below command
   $ glance image-create-via-import --disk-format qcow2 --container-format bare --name test --import-method 'glance-direct' --file <file-path>

Expected output:
Image should be imported successfully and should be in active state.

Actual output:
500 Internal Server Error: The server has either erred or is incapable of performing the requested operation. (HTTP 500)
Image remains in queued state.

glance-api logs:
----------------
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.api.v2.image_data [None req-696e90ed-1592-4287-a84c-eeaa395852a8 admin admin] Failed to stage image data due to internal error: StoreAddDisabled: Configuration for store failed. Adding images to this store is disabled.
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.api.v2.image_data Traceback (most recent call last):
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.api.v2.image_data File "/opt/stack/glance/glance/api/v2/image_data.py", line 321, in stage
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.api.v2.image_data utils.CooperativeReader(data), CONF.image_size_cap), 0)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.api.v2.image_data File "/usr/local/lib/python2.7/dist-packages/glance_store/capabilities.py", line 223, in op_checker
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.api.v2.image_data raise op_exec_map[op](**kwargs)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.api.v2.image_data StoreAddDisabled: Configuration for store failed. Adding images to this store is disabled.
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.api.v2.image_data
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi [None req-696e90ed-1592-4287-a84c-eeaa395852a8 admin admin] Caught error: Configuration for store failed. Adding images to this store is disabled.: StoreAddDisabled: Configuration for store failed. Adding images to this store is disabled.
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi Traceback (most recent call last):
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi File "/opt/stack/glance/glance/common/wsgi.py", line 1274, in __call__
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi request, **action_args)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi File "/opt/stack/glance/glance/common/wsgi.py", line 1317, in dispatch
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi return method(*args, **kwargs)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi File "/opt/stack/glance/glance/common/utils.py", line 417, in wrapped
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi return func(self, req, *args, **kwargs)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi File "/opt/stack/glance/glance/api/v2/image_data.py", line 370, in stage
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi self._restore(image_repo, image)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi File "/usr/local/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi self.force_reraise()
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi File "/usr/local/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi six.reraise(self.type_, self.value, self.tb)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi File "/opt/stack/glance/glance/api/v2/image_data.py", line 321, in stage
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi utils.CooperativeReader(data), CONF.image_size_cap), 0)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi File "/usr/local/lib/python2.7/dist-packages/glance_store/capabilities.py", line 223, in op_checker
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi raise op_exec_map[op](**kwargs)
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi StoreAddDisabled: Configuration for store failed. Adding images to this store is disabled.
Jun 26 06:28:11 ubuntu-old glance-api[24600]: ERROR glance.common.wsgi
Jun 26 06:28:11 ubuntu-old glance-api[24600]: INFO eventlet.wsgi.server [None req-696e90ed-1592-4287-a84c-eeaa395852a8 admin admin] 192.168.0.9 - - [26/Jun/2018 06:28:11] "PUT /v2/images/1520ef95-ec84-423e-977f-553d091f4ada/stage HTTP/1.1" 500 454 0.352109

[Abhishek Kekane (abhishek-kekane)]

One of the possible solution is while defining node_staging_uri config option we can use oslo_config.types.URI where we can provide a valid schemes for the same.