ActionDispatch::DebugExceptions should allow to skip logging known exceptions

[vimutter]

For instance, when user specifies rescue_responses, he might want to skip flushing those exceptions backtrace into log.

Currently both show_exceptions.rb and debug_exceptions.rb share the same option. Thus if we want show_exceptions = true, we get log for all exceptions, even for DocumentNotFound. For some cases 404 in that case is not critical situation and thus backtrace about cause of error is not required. If we set show_exceptions = false we will pass this exception to upper level, i.e. ShowException will skip handling them with rescue_responses.

I propose either to provide some options to specify which exceptions should be silenced (completely), or add some logic to deal with registered exceptions in rescue_responses.

Rails 3.2.12, Ruby 1.9.3

https://github.com/rails/rails/blob/3-2-stable/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb

[schneems]

We don't take feature requests via issues. If you want to start a discussion the best place is through the rails group, or to code up the proposed solution and submit a PR.

I don't see 404 backtraces as a huge cause of logging spam in my projects, i'm wondering if there is something else going on with your setup. I would include examples of log entries that you want to exclude and be explicit about how they will show up in both development and production (on a default app).

I'm going to close this issue for now. Let me know if you have questions.

[moiristo]

Is there already a discussion somewhere on this? To keep the logs clean in production, we have set the log level to 'warn' on production. However, ActiveRecordNotFound errors and other custom exceptions that are handled by our exceptions app are logged anyway, while it is intended behaviour. I agree with vimutter that it should be possible to silence these exceptions.

[moiristo]

I'm using the following monkeypatch now. I'll think about extending it and making it a PR when I have more time.

# This patch prevents intended exceptions (like ActiveRecord::RecordNotFound) from being written to the logs.
# It uses ActionDispatch::ExceptionWrapper.rescue_responses to filter incoming exceptions.
if Rails.env.production?

  require 'action_dispatch/http/request'
  require 'action_dispatch/middleware/exception_wrapper'

  module ActionDispatch
    # This middleware is responsible for logging exceptions and
    # showing a debugging page in case the request is local.
    class DebugExceptions
      private

      def log_error(env, wrapper)
        exception = wrapper.exception
        return if ActionDispatch::ExceptionWrapper.rescue_responses.has_key?(exception.class.name)

        logger = logger(env)
        return unless logger

        trace = wrapper.application_trace
        trace = wrapper.framework_trace if trace.empty?

        ActiveSupport::Deprecation.silence do
          message = "\n#{exception.class} (#{exception.message}):\n"
          message << exception.annoted_source_code.to_s if exception.respond_to?(:annoted_source_code)
          message << "  " << trace.join("\n  ")
          logger.fatal("#{message}\n\n")
        end
      end
    end
  end

end

[alaz]

+1 for the initial proposal.