We’re running into an issue where if we configure our kubernetes service for HTTP, Envoy will begin stripping our custom headers. As soon as we move it back to a Layer4 proxy (changing the service name prefix to something else), our headers pass into the mesh correctly. I’ve traced the network and looked into the logs - whenever Envoy determines that it needs to add the x-request-id and all the external tracing, is when it drops our headers.
The documentation for Istio/Envoy states that it’ll sanitize headers with the x- prefix, but doesn’t say anything about removing custom headers. Is this expected or is there an easy way to keep Envoy as a layer 7 proxy while being able to maintain our headers?
Our headers are prefixed with ‘wt-’ which has no value and we could change to something else if it would help.