Auto-manual instrumentations integrations in "reactive" frameworks

[iNikem]

We have documentation about how manual instrumentation can add extra attributes to a span, created by agent's auto-instrumentation. This works sufficiently well in simple, "single threaded" cases. But if I want to communicate with spans created for more "reactive" frameworks, such as Reactor Netty or Spring WebFlux, how can I be sure that Span.current() will return a correct span to me?

E.g. Reactor Netty provides a lot of callbacks (doOnResolve, doAfterResolve, doAfterRequest). It does not seem that currently those callbacks are executed with the right Otel context.

I can reach to the Netty connection and grab AttributeKey.valueOf("io.opentelemetry.javaagent.shaded.instrumentation.netty.v4_1.AttributeKeys#client-context") from that, if I know with agent's implementation details, but this is certainly a fragile and a bad way forward.