Grails multiple web sites, same web application

We had a need recently to have one web application serving many web sites, where the same data schema was in place with data shared across multiple web sites, but we wanted to show different styling and different data depending on the URI. In the end it turned out to be fairly simple. With our naming conventions, it's possible to hit one of several URIs for the same site, such as:

* project.testing.com
* project.staging.com
* project.com

So I had created a domain lookup service that when passed the request URI could work out what site the request for targeting.

def targetUri = request.getServerName()

I did a lookup for that target name against an object stored in the database relating to that targetUri and passed that back, making it available for queries for the correct data to show, and passing that down into the views to render the relevant CSS and Javascript files.