OpenStack provides a RESTful API for third-parties to connect to a providers could storage. This library allows you to use this API from a Google Apps Script.
The library can be used via the ID Mo6MqgzKidu5VYzZ7NzIM-tnfWGfgtIUb.
The library’s API is described in more detail here. Only the ‘connect’ and a general ‘get’ are implemented to date.
Here’s an example of using it:
And here is the source code: