configuration.rb

      def default_middleware_stack
        ActionDispatch::MiddlewareStack.new.tap do |middleware|
          middleware.use('::ActionDispatch::Static', lambda { paths.public.to_a.first }, :if => lambda { serve_static_assets })
          middleware.use('::Rack::Lock', :if => lambda { !allow_concurrency })
          middleware.use('::Rack::Runtime')
          middleware.use('::Rails::Rack::Logger')
          # middleware.use('::ActionDispatch::ShowExceptions', lambda { consider_all_requests_local }, :if => lambda { action_dispatch.show_exceptions })
          middleware.use("::ActionDispatch::RemoteIp", lambda { action_dispatch.ip_spoofing_check }, lambda { action_dispatch.trusted_proxies })