Hi, Gene.
Could you elaborate a bit what constitutes an issue? If I got you right, you are able to login at CAS login page. So, you are just not sure how to proceed? CAS module isn't implemented by Gluu Inc (some modifications were introduced to integrate it in the framework though), it's a third party app and you can find documentation [here](https://apereo.github.io/cas/4.0.x/index.html) (Gluu uses version 4.0.2). Hope this helps.
You will be able to modify module's config by editing files in this location of the container: `/opt/tomcat/webapps/cas/WEB-INF/`
Some CAS related settings are also stored in LDAP, to find the entry just search for `(ou=oxcas)`
I guess we don't have much docs on it because it's not that often required nowadays. May be we should add this to TO-DO list, though.
Regards,
Alex.