Debugging istio envoy 503

Hello Everyone,
Using Istio 1.2.10-gke.3 on gke

curl -v --resolve$gatewayIP -v -k

return a 503 after tls verification

< date: Tue, 19 May 2020 20:50:29 GMT
< server: istio-envoy

Now I want to track the request and identify the first point of failure by tracing the logs of the components involved and resolve the issue

The logs of the istio-ingressgateway pod show nothing. After getting a shell on the pod, I do a top and see an envoy process running, however I don’t see any logs for the envoy in /var/log/

What am I missing? Am I looking at the wrong place? Or do I need to read the code of the framework to be able to use it? I need to find out which link in the request processing chain broke first and the reason so that the same can be fixed

stackoverflow question link :