config.ru

# rackup -s thin
require 'thin'

run proc { |env|
  body = Enumerator.new do |socket|
    5.times do
      socket << "Hello"
      puts "Hello"
      sleep 1
    end
  end

  [200, { 'Content-Type' => 'text/html', "Content-Encoding" => "chunked" }, body]
}