Is x-request-id a header that was standardized in OpenTracing? Do tracing libraries such as those of OpenTelemetry or OpenTracing recognize this header and extract any tracing context from it? If not, can Envoy populate alternative headers such as the b3 (x-b3-traceid, etc.) headers automatically on incoming request?
Alternatively, is bypassing Envoy completely and dealing with the tracing context propagation headers directly using OTel libraries a good alternative? In this case, Envoy would be completely agnostic to tracing.