The Short version is that I want to know how to be able to Display GRPC Status Headers in my Istio Envoy Proxy Logs.

This link provides me a way to edit the Istio Config Map for the Format that I want- https://www.envoyproxy.io/docs/envoy/latest/configuration/access_log#format-rules

However the only documentation available is for HTTP. I want a format code for GRPC as well.

Something like

[%GRPC_STATUS_HEADER%]

which may give any of the following responses

OK = 0
CANCELED = 1
UNKNOWN = 2
INVALID_ARGUMENT = 3
DEADLINE_EXCEEDED = 4
NOT_FOUND = 5
ALREADY_EXISTS = 6
PERMISSION_DENIED = 7
RESOURCE_EXHAUSTED = 8
FAILED_PRECONDITION = 9
ABORTED = 10
OUT_OF_RANGE = 11
UNIMPLEMENTED = 12
INTERNAL = 13
UNAVAILABLE = 14
DATA_LOSS = 15
UNAUTHENTICATED = 16

I know Envoy supports this because of the following links. https://github.com/envoyproxy/envoy/pull/5682 https://www.envoyproxy.io/docs/envoy/latest/api-v2/config/filter/accesslog/v2/accesslog.proto#envoy-api-enum-config-filter-accesslog-v2-grpcstatusfilter-status

But I am not sure HOW to use it. Could someone please guide me on this? Any Help would be much appreciated!

The issue is outlined in this git link as well. https://github.com/istio/istio/issues/15358