proxy.rb

require 'goliath'
require 'em-synchrony'
require "em-synchrony/em-http"

class ProxyTest < Goliath::API
  use Goliath::Rack::Render, 'json'

  def response(env)
    http_request = EM::HttpRequest.new("http://localhost:4568#{env['REQUEST_URI']}", :connect_timeout => 1)

    request = case(env['REQUEST_METHOD'])
      when 'HEAD' then http_request.head(:keepalive => true)
      when 'GET' then http_request.get(:keepalive => true)
    end

    raise Goliath::Validation::GatewayTimeoutError.new({ "status_code" => 7, "status_message" => "Request Timed Out" }) if request.error == Errno::ECONNREFUSED

    [request.response_header.status, response_headers, request.response]
  end

  def to_http_header(k)
    k.downcase.split('_').collect { |e| e.capitalize }.join('-')
  end
end