Support for extraction of B3 headers

[stroem]

Would like to have support for extracing incomming B3 headers.
Current solution only parses xray and datadog trace id and span id.

Suggestion is to use the implementation found in dd-trace-go/tracer using env variables DD_PROPAGATION_STYLE_EXTRACT

[stroem]

Would also be good to bump dd-trace-go/tracer to get support for 128 bits B3 trace ids
See DataDog/dd-trace-go@b9e8e8c

[DarcyRaynerDD]

Hi @stroem, sorry for the late replay. We haven't prioritized any work on adding this to datadog-lambda-go, but we will continue to leave the issue open and see if it gains enough community attention. We would be happy to look at a PR adding b3 header support.

[duncanista]

@purple4reina was this fixed in #150?

[duncanista]

Hey @stroem – sorry for taking so long to take a look at this.

-- edit:

Wow, our docs our outdated, I'm going to pass it on to our team! I found the Go specific doc which suggests that you can indeed just use DD_TRACE_PROPAGATION_STYLE=B3 and it should work, since our Datadog Lambda Extension (in charge of inferring spans for some runtimes, like Go) already allows this.

--

As per the tracing propagation style docs I noticed this is not inherently available yet in Datadog's Go tracer.

For us to better triage this issue, please make sure to submit a feature request ticket in our support platform mentioning this ticket – you could also submit a ticket in the tracer's repository. Since this Library depends on tracing propagation from it, it's best to address it there!

I'm going to close the ticket, but feel free to re-open if you have any questions, or concerns!