class ExampleServiceProxy

def perform_request(env)
  request = Rack::Request.new(env)
  # use rack proxy for anything hitting our host app at /example_service
  if request.path =~ %r{^/example_service}
      backend = URI(ENV['SERVICE_URL'])
      # most backends required host set properly, but rack-proxy doesn't set this for you automatically
      # even when a backend host is passed in via the options
      env["HTTP_HOST"] = backend.host
      # This is the only path that needs to be set currently on Rails 5 & greater
      env['PATH_INFO'] = ENV['SERVICE_PATH'] || '/configuring.html'
      # don't send your sites cookies to target service, unless it is a trusted internal service that can parse all your cookies
      env['HTTP_COOKIE'] = ''
      super(env)
  else
    @app.call(env)
  end
end