Receive POST parameters from rack/Roda app

app.rb

class Test < Roda
  route do |r|
    r.root do
      '<form action="login" method="post">
        <input type="email" name="user">
        <input type="password" name="pass">
        <input type="submit">
      </form>'
    end
    r.post 'login' do
      email = request.POST['user']
      pass = request.POST['pass']
    end
  end
end

config.ru

require 'roda'
require File.expand_path('app', File.dirname(__FILE__))
run Test.app