I'm trying to track errors introduced at the traefik layer in my network. Generally speaking, traefik takes inbound traffic and routes to a variety of backend load balancers. The load balancers may also receive traffic from other sources, so I can't simply do math like "traefik-logged 500 - lb-logged 500".
I've poked around in the metrics stack a bit, as well as in log formatting, and I can't figure out how to determine whether a given status code was returned by a backend or generated by traefik itself (e.g., is a 503 because the load balancer had issues with its backends, or because traefik couldn't reach the load balancer?).
I imagine this must be possible, and I'm just missing something obvious, so would appreciate if anybody could point me in the right direction. (And if it's not actually possible, I guess I'll look into a PR.)