Modified version of the
[tracingresponse](https://github.com/open-telemetry/opentelemetry-rust-contrib/tree/main/examples/traceresponse)
example (in `contrib` repo) to demonstrate context propagation from
client to server. The example
- Removes the code to propagate trace-context as part of response
headers from server to client, as the W3C specs is still in draft
(https://w3c.github.io/trace-context/#trace-context-http-response-headers-format),
and also the propagator is part of contrib repo.
- Modify the HTTP server and client code to look more complete and also
demonstrate the context propagation across async delegates.
**_Server_** - Enhance the server's request handling, by adding support
for `/echo` and `/health` endpoints. Upon receiving the request, the
server now creates a child span, linked to the originating remote span,
and the request is forwarded to its respective delegate async task.
Furthermore, within each async task, a subsequent child span is spawned,
parented by the initial child span. This nested span creation
exemplifies the effective propagation of tracing context through the
multiple layers of async execution.
**_Client_** - The client sends requests for `/echo` and `/health`
within the context of the client root span.
Cijo Thomas
Lalit Kumar Bhasin