V3.0.0 RC1 imposes tracecontext as propagation

v2 allowed to have several tracer implementation and hence different propagation models. v3 has migrated to OTel as single tracer implementation and imposed tracecontext as the only propagation format which can be a big pain for migration. The reason is that although traefik supports tracecontext, applications have to do their tracing theirselves and forcing them all to migrate towards is not a trivial task (are the tracing libraries they use compatible with tracecontext? are they willing to upgrade or reimplement tracing for this?). I suggest you either allow it being configurable (otel already supports many propagation models opentelemetry-go-contrib/propagators at main · open-telemetry/opentelemetry-go-contrib · GitHub) or support both tracecontext and b3 as most of the tracers support b3.

For this to be noticed by the devs, I think it is better to create an issue on Github (link).

Thank you @jcchavezs and @bluepuma77.

An issue has been opened on Github.
The discussion is moving forward there.