+++ /dev/null
-require 'erb'
-
-module ActionController
- # The Failsafe middleware is usually the top-most middleware in the Rack
- # middleware chain. It returns the underlying middleware's response, but if
- # the underlying middle raises an exception then Failsafe will log the
- # exception into the Rails log file, and will attempt to return an error
- # message response.
- #
- # Failsafe is a last resort for logging errors and for telling the HTTP
- # client that something went wrong. Do not confuse this with the
- # ActionController::Rescue module, which is responsible for catching
- # exceptions at deeper levels. Unlike Failsafe, which is as simple as
- # possible, Rescue provides features that allow developers to hook into
- # the error handling logic, and can customize the error message response
- # based on the HTTP client's IP.
- 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
- $stderr.puts "Error during failsafe response: #{failsafe_error}"
- end
-
- def failsafe_response_body
- error_template_path = "#{self.class.error_file_path}/500.html"
- if File.exist?(error_template_path)
- begin
- result = render_template(error_template_path)
- rescue Exception
- result = nil
- end
- else
- result = nil
- end
- if result.nil?
- result = "<html><body><h1>500 Internal Server Error</h1>" <<
- "If you are the administrator of this website, then please read this web " <<
- "application's log file to find out what went wrong.</body></html>"
- end
- result
- end
-
- # The default 500.html uses the h() method.
- def h(text) # :nodoc:
- ERB::Util.h(text)
- end
-
- def render_template(filename)
- ERB.new(File.read(filename)).result(binding)
- end
-
- def log_failsafe_exception(exception)
- message = "/!\\ FAILSAFE /!\\ #{Time.now}\n Status: 500 Internal Server Error\n"
- message << " #{exception}\n #{exception.backtrace.join("\n ")}" if exception
- failsafe_logger.fatal(message)
- end
-
- def failsafe_logger
- if defined?(Rails) && Rails.logger
- Rails.logger
- else
- Logger.new($stderr)
- end
- end
- end
-end
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