Hello Cuba!

Before getting started, we have to install Cuba. Use the gem command:

$ gem install cuba

Now that Cuba is installed, it's easy to create a Cuba application. Open your text editor of preference and create a file called config.ru with the following code:

require "cuba"

Cuba.define do
  on root do
    res.write("Hello, Cuba!")
  end
end

run(Cuba)

You already have a functional Cuba application! To see it in action, type rackup config.ru in the command line.

Now open a browser and navigate to http://localhost:9292/. It should show a greeting message as shown below:

NOTE: To stop the web server, hit Ctrl+C in the terminal window where it's running. To verify the server has stopped you should see your command prompt cursor again.

As you can see, the syntax is very readable. We'll discuss the details in the next section.