NIFI-15286 Verify nodes connect-ability in Kafka3ConnectionService

[dariuszseweryn]

If not-authorized to describe the cluster, verify connect-ability to bootstrap servers.

Summary

NIFI-15286

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Build

• Build completed using ./mvnw clean install -P contrib-check
  • JDK 21
  • JDK 25

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[exceptionfactory]

Thanks for providing this improvement @dariuszseweryn. The general approach looks good. I noted some initial recommendations, and plan to take a closer look at some of the implementation details.

[exceptionfactory]

Thanks again for putting this together @dariuszseweryn.

On closer review, I noticed a few issues, particularly in relation to the order of operations. This initial approach verifies node connectivity after listing topics, which already implies some level of connectivity. I also noticed the introduction of several intermediate record context classes which did not seem necessary after some restructuring.

To help move things forward, I put together a new pull request #10689 and listed you as a co-author on the commit.

[pvillard31]

Closing this one as #10689 will be merged shortly.