A simple Ruby Framework for you understand Rack(Ruby Webserver Interface)

• gem install under_rack

• create a new file called app.ru with:

  require "rubygems"
  require "under_rack"
  
  get "/hello" do
    @name = "Mary"
    erb :hello
  end
  
  post "/create" do
    "Created"
  end
  
  app_root = get "/" do
   "Home"
  end
  
  run app_root
  

• Create a new file called hello.erb with:

  <p>Hello <%= @name %></p>

• Run the application with: rackup app.ru

• Go to localhost:9292/hello