Why can't I set ActionController Relative URL Root in a JRuby on Rails app running on Jetty?

Question

I am developing a Ruby on Rails app but am running it with JRuby in Jetty under a context path of /app.

I'm using Rails 3.0.5, JRuby 1.6.0 and Jetty 6.1.22

When I deploy to Jetty, the relative URLs of the static resources is /stylesheets/* and /javascripts/*, not /app/stylesheets/* and /app/javascripts/* and is hence breaking styling and client-side functionality.

I tried adding config.action_controller.relative_url_root = '/app' to config/environments/production.rb but Jetty cannot initialise the application.

The stack trace from Jetty looks like:

2011-03-23 16:19:54.062:WARN:/app:Error: application initialization failed org.jruby.rack.RackInitializationException: unable to create shared application instance at org.jruby.rack.SharedRackApplicationFactory.init(SharedRackApplicationFactory.java:39) at org.jruby.rack.RackServletContextListener.contextInitialized(RackServletContextListener.java:44) at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548) at org.mortbay.jetty.servlet.Context.startContext(Context.java:136) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152) at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130) at org.mortbay.jetty.Server.doStart(Server.java:224) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.xml.XmlConfiguration.main(XmlConfiguration.java:985) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.mortbay.start.Main.invokeMain(Main.java:194) at org.mortbay.start.Main.start(Main.java:534) at org.mortbay.start.Main.start(Main.java:441) at org.mortbay.start.Main.main(Main.java:119)

How can I configure this setting and not have Jetty blow up when initialising the app?

Answer 1

config.action_controller.relative_url_root is removed in Rails 3. I have a post about this on my website: Deploying a Rails 3.1 app to subdirectory in Apache. Though it's written for Apache, you should be able to rewrite it to Jetty.