[CRD-v1] Deprecate / remove the resources configuration in the `.spec.kafka` in Kafka CR?

[scholzj]

In #11791 we discussed the duplication of fields between Kafka.spec.kafka.template and KafkaNodePool.spec.template and decided to keep it. Nudged by some unrelated discussion, I realized we have the same duplication also for other fields:

• resource requests (Kafka.spec.kafka.resources versus KafkaNodePool.spec.resources)
• JVM Options (Kafka.spec.kafka.jvmOptions versus KafkaNodePool.spec.jvmOptions)

Do we want to keep these ones as well going forward in the v1 API? Or should we deprecated and remove these from the Kafka CR? I think the logic we applied to the template sticks with JVM Options. But not 100% sure if I see it the same way for the resource configuration. Any thoughts?

[ppatierno]

I am totally +1 for the jvmOptions to keep them.

But not 100% sure if I see it the same way for the resource configuration. Any thoughts?

What are your doubts on keeping resources as well. Isn't it possible that users define resources within the Kafka CRs going to be applied to all nodes within the cluster (brokers and controllers) but then specializing only the brokers (or controllers) resources within the corresponding KafkaNodePool(s). Keeping in both I always see as a way to avoid repeating the same configuration across several node pools.

[scholzj]

It is possible. Just not sure how likely it is.

But I do not have a strong opinion on it TBH. The way I see it, we get the last chance to change this if we want to for another N years. So it is worth discussing every piece of the API we have at least a little bit of doubt about 😉.

[scholzj]

Triaged on 2.10.2025: Seems like deprecating and removing the resources from the Kafka CR makes sense. The JVM options seem to make sense to live in both resources. Needs a proposal.

[scholzj]

Proposal opened in strimzi/proposals#182