Service catalog randomly returned endpoint if there were multiple choice.

[Yang Youseok]

in keystoneauth1/access/service_catalog.py

endpoint_data_for() function just returned first candidate of entry points by endpoint_data_list[0] when there were multiple choice for endpoints.

Since there is no guarantee for endpoint order, I found that if client API did not specify any scope like region, an endpoint returned is changed randomly.

imho, library code should provide precisely defined behavior, so that client can expect and maybe this case could raise mulitiple choice exception.

Thanks.

[Morgan Fainberg (mdrnstm)]

This is reasonable, but will likely need to be opt-in to conform to the keystoneauth strict contract for behavior.