initializer.rb

paths = Dir[Rails.root.join("config/routes/**/*.rb")]
updater = ActiveSupport::FileUpdateChecker.new(paths) { Rails.application.routes_reloader.reload!; Rails.logger.debug('shita') }

Rails.application.configure do
  config.to_prepare do
    puts 'updated status: ' + updater.updated?.to_s
    Rails.logger.debug('shita')
    updater.execute_if_updated
  end
end