Controller unhandled errors should be passed as BadStatus to interceptors

[ximus]

While using Gruf::Interceptors::Instrumentation::RequestLogging::Interceptor, I noticed that in the event of unhandled errors raised in my controller (errors that are not of type GRPC::BadStatus or raised via fail!), I was not getting any request logging in my log.

In a successful controller call I would get something like:

[GRPC::Ok] (list_units) [5.24ms] [GRPC::Ok] (rpc.units.list_units) Parameters: {:is_active=>false, :check_can_delete=>false}

If an unhandled error was raised I would get nothing.

My assumption is that I should still get logging in that case. Request info is useful to have, including when an unhandled error occurs.

Investingating why I wasn't getting any, I observed that in Gruf::Interceptors::Instrumentation::RequestLogging::Interceptor, the interceptor yields to the controller via this line:

result = Gruf::Interceptors::Timer.time(&block)

Gruf::Interceptors::Timer.time knows to rescue and handle errors, but only of type GRPC::BadStatus. I realized that unhandled errors would not be caught by it, hence the error logging interceptor would get exited right there and never log.

I noticed that the base controller code turns unhandled errors in the GRPC::BadStatus errors. But it only does so after all the interceptors have run (or been tripped as above). I thought why not just do this before the interceptors. Seeing how the logging interceptor is designed, maybe it was even meant to be that way. So this is what I propose here.

It works well for me so far.

API changes:

• Now interceptors will get a GRPC::BadStatus error in the case of unhandled errors, instead of the original unhandled error. To reach the original error, GRPC::BadStatus#cause can be used.

[ximus]

wondering if interceptors like gruf-sentry should be updated to log cause in the case of internal errors

[mochja]

Is there plan to merge the fix? I do experience similar problem with the ConnectionReset Interceptor when the database does not exists,