ActiveSpan is too Opaque

[rbtcollins]

We'd like to be able to use the TraceId from the ActiveSpan in three additional contexts

• In external logs, so we can silo sensitive data from the widely-accessed tracing console but still correlate
• In response headers, so that we can do browser integration and directly link to the resulting trace from our UI for developers
• In request headers when using external APIs that support correlation e.g with x-request-id, so that we can ask their support to examine a particular request.

Right now we cannot because traceId is considered an implementation detail, not part of the contract.

[devinsba]

There is an ongoing discussion of this: opentracing/specification#24

[tedsuo]

I agree @rbtcollins, I want to push on this once #189 is over.

[cwe1ss]

fyi, this is currently getting specified with opentracing/specification#109

[carlosalberto]

Wondering if we should close this Issue, as there's already an ongoing discussion (as Christian pointed out), as well as #280?

@rbtcollins ok to close it? ;)

[rbtcollins]

Closed in favour of the PR