Netflix Feign - Propagate Status and Exception through Microservices

Question

I\'m using Netflix Feign to call to one operation of a Microservice A to other other operation of a Microservice B which validates a code using Spring Boot.

The operation

Answer 1

OpenFeign's FeignException doesn't bind to a specific HTTP status (i.e. doesn't use Spring's @ResponseStatus annotation), which makes Spring default to 500 whenever faced with a FeignException. That's okay because a FeignException can have numerous causes that can't be related to a particular HTTP status.

However you can change the way that Spring handles FeignExceptions. Simply define an ExceptionHandler that handles the FeignException the way you need it (see here):

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(FeignException.class)
    public String handleFeignStatusException(FeignException e, HttpServletResponse response) {
        response.setStatus(e.status());
        return "feignError";
    }

}

This example makes Spring return the same HTTP status that you received from Microservice B. You can go further and also return the original response body:

response.getOutputStream().write(e.content());