module ActionDispatch class Failsafe cattr_accessor :error_file_path self.error_file_path = Rails.public_path if defined?(Rails.public_path) def initialize(app) @app = app end def call(env) @app.call(env) rescue Exception => exception # Reraise exception in test environment if defined?(Rails) && Rails.env.test? raise exception else failsafe_response(exception) end end private def failsafe_response(exception) log_failsafe_exception(exception) [500, {'Content-Type' => 'text/html'}, failsafe_response_body] rescue Exception => failsafe_error # Logger or IO errors $stderr.puts "Error during failsafe response: #{failsafe_error}" end def failsafe_response_body error_path = "#{self.class.error_file_path}/500.html" if File.exist?(error_path) [File.read(error_path)] else ["

500 Internal Server Error

"] end end def log_failsafe_exception(exception) message = "/!\\ FAILSAFE /!\\ #{Time.now}\n Status: 500 Internal Server Error\n" message << " #{exception}\n #{exception.backtrace.join("\n ")}" if exception failsafe_logger.fatal(message) end def failsafe_logger if defined?(Rails) && Rails.logger Rails.logger else Logger.new($stderr) end end end end