Hi,
Yes, a Ruby REST API client for GeoServer has been released. I did it a couple of days ago. I was waiting to add more functionality before announcing it to the list but, given that it's already out, I would like to invite geo rubystas to check it out:
https://github.com/rnz0/rgeoserver
This is part of an effort to automate ingestion of geospatial data at Stanford University Libraries.
Thanks,
Renzo Sanchez-Silva
GIS Infrastructure Software Engineer
Digital Library Systems and Services
Stanford University Libraries and Academic Information Resources