gistfile1.rb

$_rack_request_counter = 0
$_rack_rails_app = nil
rails_dispatcher = lambda{|env|
  $_rack_request_counter += 1
  if $_rack_request_counter <= 1
    if env["REQUEST_METHOD"]=="GET"
      res = Rack::Response.new("*", 302)
      redir_url = env["REQUEST_URI"] + (env["QUERY_STRING"]=="" ? "?" : "&") + "_spinup_=#{Time.now.to_i}"
      res["Location"] = redir_url
      res.finish
    else
      Rack::Response.new("Service Unavailable", 503).finish
    end
  else
    unless $_rack_rails_app
      require ::File.expand_path('../config/environment', __FILE__)
      $_rack_rails_app = ActionController::Dispatcher.new
    end
    $_rack_rails_app.call(env)
  end
}
#map '/admin' do
#  use AppEngine::Rack::AdminRequired
#  run rails_dispatcher
#end
map '/' do
  run rails_dispatcher
end