Question

I’ve been messing with Rack a lot lately, and am wondering how you could startup a Rack server by running a file (e.g. app.rb) without the use of config.ru. Is this possible, or is it a more complex method?

Answer 1

You can use the built-in WEBrick server instead. So where you might normally have something like this:

# app.rb
class App
  def call(env)
    return [200, {"Content-Type" => "text/html"}, "Hello, World!"]
  end
end

# config.ru
require 'app'
run App.new

You can instead consolidate it and just run ruby app.rb directly:

#app.rb
class App
  def call(env)
    return [200, {"Content-Type" => "text/html"}, "Hello, World!"]
  end
end

Rack::Handler::WEBrick.run(App.new, :Port => 9292)