But if I add this to Tomcat's server.xml file, nothing can be deployed, and Jboss throws a ton of error messages about failed deployment. Basically, almost everything under the deploy directory can't be deployed.
In fact, Tomcat is not even started at all. I tried absolute path for docBase too, but that wouldn't help. That exact same way of configuration works just fine with Tomcat standalone, but wouldn't do when Tomcat is embedded in JBoss.
How can I use the context valve in Tomcat to do that? Or is there a better way?