Problems with rails 4 in production environment - ruby-on-rails

Question

I create a new rails 4beta1 app (ruby 2.0) from scratch and when I launch de server in development mode it runs fine but when I try in production it doesn't.
I already try to run bundle exec rake assets:precompile RAILS_ENV=production and change the config.serve_static_assets to true in the config/environments/production file but I still got the error:
=> Booting WEBrick
=> Rails 4.0.0.beta1 application starting in production on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
[2013-04-03 11:53:46] INFO WEBrick 1.3.1
[2013-04-03 11:53:46] INFO ruby 2.0.0 (2013-02-24) [x86_64-darwin12.2.0]
[2013-04-03 11:53:46] INFO WEBrick::HTTPServer#start: pid=13848 port=3000
I, [2013-04-03T11:53:50.521162 #13848] INFO -- : Started GET "/" for 127.0.0.1 at 2013-04-03 11:53:50 +0100
F, [2013-04-03T11:53:50.695426 #13848] FATAL -- :
ActionController::RoutingError (No route matches [GET] "/"):
actionpack (4.0.0.beta1) lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call'
actionpack (4.0.0.beta1) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.0.0.beta1) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.0.0.beta1) lib/rails/rack/logger.rb:21:in `block in call'
activesupport (4.0.0.beta1) lib/active_support/tagged_logging.rb:67:in `block in tagged'
activesupport (4.0.0.beta1) lib/active_support/tagged_logging.rb:25:in `tagged'
activesupport (4.0.0.beta1) lib/active_support/tagged_logging.rb:67:in `tagged'
railties (4.0.0.beta1) lib/rails/rack/logger.rb:21:in `call'
actionpack (4.0.0.beta1) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.5.2) lib/rack/methodoverride.rb:21:in `call'
rack (1.5.2) lib/rack/runtime.rb:17:in `call'
activesupport (4.0.0.beta1) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
actionpack (4.0.0.beta1) lib/action_dispatch/middleware/static.rb:64:in `call'
railties (4.0.0.beta1) lib/rails/engine.rb:510:in `call'
railties (4.0.0.beta1) lib/rails/application.rb:96:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
rack (1.5.2) lib/rack/content_length.rb:14:in `call'
rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
/Users/jbatista/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/Users/jbatista/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/Users/jbatista/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
Webpage error:

Answer 1

In Rails 4.0, for technical reasons the default Rails page doesn't work on production environment, this includes any server (like heroku). The good news is that the error will go away when you start add controllers, set routes, etc...
Just start development and you'll be fine.

Answer 2

also looks like you need to define the root route in config/routes.rb
something like
MyApp::Application.routes.draw do
root :to => "MyApp#index"
end
where MyApp refers to your applications name.

Answer 3

In config/environments/production.rb serve_static_assets should be false because in production their server will handle them.
config.serve_static_assets = false
Moreover, you should not use WEBrick in production, it should only be used in development. Go for thin for example instead.
Basically, add gem 'thin' to our Gemfile.