Deploying and running your rails applications on GlassFish gem is easiest and fastest way. GlassFish gem consists only of v3 kernel, grizzly and some utilities and thus smaller size and faster startup time. All you need is to install GlassFish gem, that will be one time install only. Then simply run your rails application with the GlassFish gem.
gem install glassfish
This will install GlassFish gem.
glassfish
The application is deployed at http://localhost:3000/say/hello and ready to accept requests