config.ru

# Static site using Rack (with expire headers and etag support)... great for hosting static sites on Heroku

require File.dirname(__FILE__) + '/vendor/gems/environment'
Bundler.require_env
require 'rack/contrib'
require 'rack-rewrite'

use Rack::StaticCache, :urls => ['/images','/css','/favicon.ico'], :root => "public"
use Rack::ETag
use Rack::Rewrite do
  rewrite '/', '/index.html'
end
run Rack::Directory.new('public')

Gemfile

gem 'rack-contrib', :git => 'git://github.com/rack/rack-contrib.git'
gem 'rack-rewrite'