Emit spans with the proper span kind

[LeBoucEtMistere]

Hello folks

I noticed that all spans emitted by the restate server telemetry have the default span kind "Internal". I would expect the top level spans of the restate ingress to have the "Server" span type and the invocation top level spans to have the "Consumer" span type. Would it be possible to support this ? A lot of telemetry backends rely on the span type for displaying data properly and in my case, I noticed my telemetry backend fails to properly display my restate service metrics because of this.

For reference: https://opentelemetry.io/docs/concepts/signals/traces/#span-kind

Thanks for the great work on restate 🙏

[tillrohrmann]

Thanks a lot for raising this issue @LeBoucEtMistere. I think it makes a lot of sense to update the span type. Pulling in @slinkydeveloper who is the expert on this matter from our side.