kafka embedded doesn't start for unit tests

[msillence]

Expected Behavior

adding the property kafka.embedded.enabled=true should start kafka so unit tests work

Actual Behaviour

unit tests fail trying to connect to kafka

Steps To Reproduce

From the documentation https://micronaut-projects.github.io/micronaut-kafka/latest/guide/#kafkaEmbedded

I believe that kafka.embedded.enabled=true should start kafka embedded for the unit tests

I find the test fail looping trying to connect, however if I add the annoation @Requires(property = "foo.bar", value = "stuff") then the tests all pass ( the don't use or need that property ) I added this as part of following the how to add per class lifecyle listeners ( I was going to try and spin up a kafka test container ) I'd much prefer not to spin up a container as it is much quicker using the embedded kafka

I feel this annotation is obviously a side effect and would like to know the correct way to spin up the embeded kafka

I've also tried the annotation from https://blog.wick.technology/micronaut-testing-kafka/ adding @MicronautTest(environments = "kafka") but that makes no difference

Environment Information

ubuntu linux (WSL2) / windows java 17

Example Application

https://github.com/msillence/micronaut-kafka-unit-test

Version

3.1.3

[graemerocher]

Support for embedding kafka was removed in version 4.0.0 in favour of test containers, the documentation should have been corrected for this though

[graemerocher]

See for example https://guides.micronaut.io/latest/micronaut-kafka-gradle-java.html

[msillence]

Thanks for the quick reply, is it possible to start up the kafka container once for all the tests? Is there some overall test lifecycle listener option? It seems when I include the postgres test container that automatically starts up without any codea and runs for all the tests? - actually that's not right postgres seems to start up for each test class as well.

[graemerocher]

Sure https://www.testcontainers.org/test_framework_integration/manual_lifecycle_control/#singleton-containers

[graemerocher]

A more complete example for JUnit 5 would look something like:

abstract class AbstractKafkaTest implements TestPropertyProvider {

    static final KafkaContainer MY_KAFKA;

    static {
        MY_KAFKA = new KafkaContainer(
            DockerImageName.parse("confluentinc/cp-kafka:latest")); 
        MY_KAFKA.start();
    }

     @Override
    public Map<String, String> getProperties() {
        return Collections.singletonMap(
                "kafka.bootstrap.servers", MY_KAFKA.getBootstrapServers() 
        );
    }
}

And then test:

@MicronautTest
class MyTest extends AbstractKafkaTest {

}

[msillence]

that's fantastic, thank you. do you want to close this or should we keep this open as a reminder to update the docs?

[graemerocher]

leaving it here as a reminder :)