6.4. root :to => 'welcome#index'

In the default config/routes.rb file you will find the following comment quite a long way down:
  # You can have the root of your site routed with "root"
  # just remember to delete public/index.html.
  # root :to => 'welcome#index'
If you comment out the last line there, you can define your http://0.0.0.0:3000/ with it. Let's put it on home#index:
Shop::Application.routes.draw do
  get "home/index"

  get "home/ping"

  get "home/pong"

  root :to => "home#index"
end

Important

After setting the root route please do not forget to delete the file /public/index.html!
$ rm public/index.html 
$
Our new routes:
$ rake routes
home_index GET /home/index(.:format) home#index
 home_ping GET /home/ping(.:format)  home#ping
 home_pong GET /home/pong(.:format)  home#pong
      root     /                     home#index
$
If we go to the root URL http://0.0.0.0:3000 we now see home#index.
The route "/" takes us to home#index

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