ContainerProperties from KafkaListenerContainerFactory are dropped

[thomasmey]

Hi,

I think the overwritten method here

spring-kafka/spring-kafka/src/main/java/org/springframework/kafka/config/ConcurrentKafkaListenerContainerFactory.java

Line 61 in 1c79866

protected ConcurrentMessageListenerContainer<K, V> createContainerInstance(KafkaListenerEndpoint endpoint) {

has a bug, as that it does not use the already existing container properties from super class org.springframework.kafka.config.AbstractKafkaListenerContainerFactory.containerProperties

So it basically drops any configuration like container clientId (!)

What do you think, bug or feature?

[garyrussell]

If that were the case, nothing would work.

The properties are copied in later; see

spring-kafka/spring-kafka/src/main/java/org/springframework/kafka/config/AbstractKafkaListenerContainerFactory.java

Lines 402 to 405 in 1c79866

	protected void initializeContainer(C instance, KafkaListenerEndpoint endpoint) {
	ContainerProperties properties = instance.getContainerProperties();
	BeanUtils.copyProperties(this.containerProperties, properties, "topics", "topicPartitions", "topicPattern",
	"messageListener", "ackCount", "ackTime", "subBatchPerPartition");

[thomasmey]

Hi,

mhh, I think I see now where the confusion comes from:

when I do:
@Bean public ConcurrentKafkaListenerContainerFactory<String, String> kafkaListenerContainerFactory() { ConcurrentKafkaListenerContainerFactory<String, String> factory = new ConcurrentKafkaListenerContainerFactory<>(); factory.getContainerProperties().setClientId("clientId"); return factory; }
this can not work with the current code. the question is: should this (set a container client id programatically)?

makes sense?

[garyrussell]

My apologies; I see it does NOT work in that case. Investigating...

[garyrussell]

The client Id comes from the endpoint (populated from the @KafkaListener) and overwrites the container properties, even if not set (which is a bug).

If you want to change it programmatically, use a container customizer instead...

factory.setContainerCustomizer(container -> {
	container.getContainerProperties().setClientId("client-for-"
			+ container.getContainerProperties().getTopics()[0]);
});

[thomasmey]

My apologies; I see it does NOT work in that case. Investigating...

No, worries.
Thanks for looking into it 😃