os-client-config is a library for collecting client configuration for using an
OpenStack cloud in a consistent and comprehensive manner. It will find cloud
config for as few as 1 cloud and as many as you want to put in a config file. It
will read environment variables and config files, and it also contains some
vendor specific default values so that you don't have to know extra info to use
OpenStack.

See also: https://github.com/openstack/os-client-config