glance-api fails if cinder_volume_type is set and auth data is not overriden

[Jorge Merlino]

When configuring multiple cinder storage backends in glance-api.conf a volume type must be configured using the cinder_volume_type configuration option. If this parameter is set but not all of these parameters are set also:

cinder_store_user_name
cinder_store_password
cinder_store_project_name
cinder_store_auth_address

glance-api will not start. These last four parameters are supposed to be optional and the default context should be used if they are not present.

The issue arises on the _drivers/cinder/store.py file, in particular starting on the configure_add function. This function invokes self.get_cinderclient() (line 533) with no parameters if cinder_volume_type is present. So, in this function invocation the context paramter is None and the legacy_update parameter is False (default values of the parameters). Thus, if any of the mentioned four parameters is not set, the self.is_user_overriden() method call will also return false. In this case, where legacy_update and user_overriden are both false, get_cinderclient will reach line 606 where username is set to context.user_id. But in this function path, context still has its default value (None) and glance-api will fail showing this error in the systemd journal:

ERROR: 'NoneType' object has no attribute 'user_id'

In this case, context should be set to the default context before reaching this line.