Upgrade to Brave 6 and Zipkin Reporter 3

[codefromthecrypt]

This updates to Brave 6 and Zipkin Reporter 3 which are compatible with the classpath of Otel 1.35

Here are some new features for end-users, applicable to both Otel and Brave senders:

• Use protobuf by setting the property "management.zipkin.tracing.encoding" to "PROTO3"
• Integrate a dynamic zipkin endpoint source by providing a bean HttpEndpointSupplier.Factory
  • This will allow spring-cloud-loadbalancer or discovery integration like sleuth had, but also for otel
  • The input to this function is ZipkinConnectionDetails.getSpanEndpoint()
  • When absent ZipkinConnectionDetails.getSpanEndpoint() is called once like before.

[wilkinsona]

Thanks for the PR, @codefromthecrypt.

[codefromthecrypt]

@wilkinsona I think we can get away from all these deprecated things, sorry about the distraction. I'll mark draft and triple check!

[codefromthecrypt]

should be an easier review, now. I had to add the zipkin-reporter bom not because of code in this change, but because Brave 6 no longer manages zipkin-reporter (Brave 6 has no dependency on zipkin types). spring-boot-actuator-autoconfigure defines reporter types, so needs this for those to compile. When that code updates to Zipkin Reporter 3 is up to you, I'm fine helping soon, but if not this week I can't promise availability as this stuff isn't related to my dayjob anymore.

[codefromthecrypt]

actually update to zipkin-reporter v3 will need to wait until this is released, as it seems boot is also importing otel exporter for OpenTelemetryConfiguration (note brave doesn't actually use this type). Anyway, migration to v3 is changing packages, so anyone can do it similar to this openzipkin/zipkin-aws#208

[wilkinsona]

We can't upgrade to Brave 6.0 until Micrometer has done so.

[codefromthecrypt]

@efemoney I think the current status is micrometer are awaiting https://github.com/open-telemetry/opentelemetry-java to release 1.35.0. Then micrometer can update to that and brave 6 etc per notes here. Once micrometer is converged, then this one can progress. Finally, we can basically not do this again for several years :)

TL;DR; waiting on otel to release and I don't know the schedule of that

[efemoney]

Thank you. I checked the micrometer PR but somehow missed that 🙌🏾

[codefromthecrypt]

turns out micrometer-metrics/tracing#536 only affected test deps as there was no main code change. So, there's no inter-dependency afaict except maybe if otel latest is needed here. Anyway I will sort this out next!

[codefromthecrypt]

ok there's probably a lint or some test glitch, but I'm time out for the day.

Effectively, we don't want to depend on zipkin core (zipkin.Reporter) types anymore, so detecting Brave already configured if there is an AsyncZipkinSpanHandler rather wrapping and bringing back a zipkin dep with AsyncReporter

Also, almost everyone uses json and there's no built-in set of encoders in brave. So, I used optional injection of an encoder for both use cases brave and otel. The only known custom user of that encoder would be zipkin-gcp, and again lacking any built-in choice except json, optional is the best way.

Feedback welcome, but I think you can see where I'm going with this and it is a lot simpler to implement.

[mhalbritter]

Thanks a lot for the PR, there are some cool features in there! :)

[codefromthecrypt]

rebased with feedback from @mhalbritter accepted! 🤞 on green

[codefromthecrypt]

red looks unrelated unless I'm missing something

[codefromthecrypt]

rebased. let me know what else is needed here!

[codefromthecrypt]

same snapshot download error as before..

[mhalbritter]

Don't worry. I'll take a look at the PR and merge it. It builds fine on my machine.

[mhalbritter]

Thanks a lot for the PR!

[codefromthecrypt]

thanks @mhalbritter .. one less thing on my nag list, but more importantly a big step forward for those using this stuff. cheers!