I want to configure my container to

  1. provide authentication
  2. enable observability for the listener
  3. obey the spring configuration e.g. spring.kafka.consumer.auto-offset-reset: earliest for testing with embedded kafka

I found this solution

@Bean                                                                 
fun kafkaListenerContainerFactory(                                    
    consumerFactory: ConsumerFactory<Any, Any>,                       
    configurer: ConcurrentKafkaListenerContainerFactoryConfigurer     
): ConcurrentKafkaListenerContainerFactory<Any, Any> {                
    val factory = ConcurrentKafkaListenerContainerFactory<Any, Any>() 
    configurer.configure(factory, consumerFactory)                    
    factory.setContainerCustomizer {                                   
        it.containerProperties.isObservationEnabled = true            
        it.containerProperties.kafkaConsumerProperties = properites2()
    }                                                                 
    return factory                                                    
}

So basically I just want to set the containerCustomizer But I think it could be achieved easier if the KafkaAnnotationDrivenConfiguration would take a ContainerCustomizer into account.

This should imho be sufficient to achieve the goal?

@Bean                                                                                                            
fun containerCustomizer() = object: ContainerCustomizer<Any, Any, ConcurrentMessageListenerContainer<Any, Any>> {
    override fun configure(container: ConcurrentMessageListenerContainer<Any, Any>) {                            
        container.containerProperties.isObservationEnabled = true                                                
        container.containerProperties.kafkaConsumerProperties = properties()                                    
    }                                                                                                            
}

I want to mess around with the factories as little as possible to not break the default configuration.

Comment From: mhalbritter

Superseded by #34033