The people at Kontena have an excellent tutorial on how to set up Kontena and rexray to work with Wasabi. You can find out more here:
http://blog.kontena.io/wasabi-s3-with-containers/
Note that this example discusses the use of Wasabi's us-east-1 storage region. To use other Wasabi storage regions, please use the appropriate Wasabi service URL as described in this article.