Change default container in scalatra web application in eclipse

Question

I am a total beginner with developing in scalatra, eclipse, sbt, web services, etc...coming from a proprietary SAP Abap world where everything is different. Recently I found interest in developing in scala and SAP opens its SAP Cloud Platform, so I tried some tutorials to create some very simple web applications.

I could manage to create the sample tutorial with scalatra and sbt.

Scalatra includes Jetty as a default container.

I want to use Eclipse as SAP uses it as a standard development environment. I managed also to install the sbt-eclipse plugin and could import the project into the eclipse environment.

But now I'm stuck.

How can I change the web-container (server) to Tomcat which is installed locally in my eclipse environment?
It is a Scala project, so I cannot use the option which is available in a J2EE project to define the Target Runtime Environment in the properties.

Ultimately I would like to deploy it to my Hana trial account at SAP Cloud Platform. Any hint is appreciated.