A new version of the OpenTracing API for C++11 is almost ready (opentracing/opentracing-cpp#11). Once it has been merged, we will be changing the LightStep tracer so that it is OT-compatible. It would be great if we could then do the following with Envoy:

• extract the ZipKin tracer and use it as the basis for a new OT-compatible ZipKin C++ tracer
• reimplement the tracing instrumentation in Envoy to use the OpenTracing API.
• support linking to 3rd-party OT tracers beyond lightstep and zipkin.

We're happy to put the work in to make this happen. Any recommendations or objections?