Have us (within wasm, e.g. pre auth RL?) start the trace and is there a way to have envoy propagate that traceparent to ext-auth?

[david-martin]

(split out from original body of work in Kuadrant/architecture#48)

Currently, trace IDs do not propagate to wasm modules in Istio/Envoy, affecting trace continuity in Limitador. This means that requests passed to limitador will not have the relavant 'parent' trace ID in its trace information. If however the trace initiation point is outside of Envoy/Istio, the 'parent' trace ID will be available to limitador and included in traces passed to the collector. This has an impact on correlating traces from limitador with traces from authorino, the gateway and any other components in the path of requests.

If a traceid is not available on a request, and tracing is enabled in limitador and/or authorino, a trace should be started within the wasm-shim and made available to limitador and authorino.

To avoid extra effort implementing a solution for propagating a traceparent to ext-authz, it may make sense to do
#58 first.