Is it possible to run undertow on <1024 port as root and then downgrade user to non-root one? Dropwizard (jetty in fact) framework has such feature (see #1), it just needs libsetuid.so loaded. Any alternative mechanism?

#1 http://www.dropwizard.io/0.7.0/dropwizard-core/apidocs/io/dropwizard/server/AbstractServerFactory.html

Regards

Grzegorz