Return traceid (and, in general, context info) into header response

[ziomill]

Hello,

We are using java automatic instrumentation in some Java SpringBoot microservices. We have also adopted the "W3C Trace Context" strategy for Context propagation.

We would return some context info (like the traceid) into the Response Headers. Is there a way to access to these params, in a standard way, through the OpenTelemetry SDK?

Of course, we could simply read the headers by their key name (ex.: traceparent) but, in my opinion, this will introduce a strong coupling with the "W3C Trace context" strategy, which we would avoid if possible.

Thank you

[jkwatson]

Span.current().getSpanContext() should give you what you need, I think.

[ziomill]

Hi @jkwatson,
It's exactly what I was looking for:

   String traceId = spanContext.getTraceId();
   String parentId = spanContext.getSpanId();
   String traceFlags = spanContext.getTraceFlags().asHex();

Thank you.