[Enhancement]: Explicitly add JmxReporter to metric.reporters when JMX Exporter is enabled

[fvaleri]

Related problem

In Kafka 4.0.0, the org.apache.kafka.common.metrics.JmxReporter will still be enabled by default, but the user will need to explicitly add this plugin to the metric.reporters property when setting any other custom metrics plugin. This means that, with the current Cluster Operator reconciliation logic, the JMX Prometheus Exporter would not work when Cruise Control is also enabled.

Suggested solution

Update the Cluster Operator Kafka cluster configuration reconciliation to explicitly add the org.apache.kafka.common.metrics.JmxReporter to metric.reporters when JMX Prometheus Exporter is enabled.

Alternatives

No response

Additional context

No response

[OwenCorrigan76]

I'm interested in woking on this. I'll discuss with @fvaleri after the community call on Jan 9th.

[im-konge]

Triaged on 9.1.2025: This makes sense to have fixed and it seems that @OwenCorrigan76 already volunteered for fixing the issue.