when running multiple junit test classes, getting error "A docker instance is starting or already started"

[assafcoh]

To test our opensearch cluster functionality we have many Junit 5 tests using localstack-utils annotations as below.

@ExtendWith(LocalstackDockerExtension.class)
@LocalstackDockerProperties(portEdge = "3000", portElasticSearch = "3100", services ={ServiceName.S3, ServiceName.ELASTICSEARCH_SERVICE })
@ExtendWith(SpringExtension.class)
public class MyOpenSearchTest{
...
}

Everything works fine when running the junit tests one by one.
However, since we have many test classes and it takes ~1 minute for the docker container to startup, we tried to speed up overall test duration by doing the following:

1. use a different portEdge and portElasticSearch in @LocalstackDockerProperties for each junit test class
2. we enabled parralel junit tets execution by adding the lines below to file /resources/junit-platform.properties

junit.jupiter.execution.parallel.enabled = true
junit.jupiter.execution.parallel.config.dynamic.factor = 1

With the above chganges, the junit tests are started in parallel but we get this error:

java.lang.IllegalStateException: A docker instance is starting or already started.

	at cloud.localstack.Localstack.startup(Localstack.java:67)
	at cloud.localstack.docker.LocalstackDockerExtension$StartedLocalStack.<init>(LocalstackDockerExtension.java:57)
	at cloud.localstack.docker.LocalstackDockerExtension.beforeAll(LocalstackDockerExtension.java:42)
	at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$invokeBeforeAllCallbacks$7(ClassTestDescriptor.java:358)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
	at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.invokeBeforeAllCallbacks(ClassTestDescriptor.java:358)
	at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.before(ClassTestDescriptor.java:197)
	at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.before(ClassTestDescriptor.java:74)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:102)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:95)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:71)
	at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService$ExclusiveTask.compute(ForkJoinPoolHierarchicalTestExecutorService.java:169)
	at java.base/java.util.concurrent.RecursiveAction.exec(RecursiveAction.java:194)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1311)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1840)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1806)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:177)

we are using this dependency:

<dependency>
 <groupId>cloud.localstack</groupId>
 <artifactId>localstack-utils</artifactId>
 <version>0.2.22</version>
 <scope>test</scope>
</dependency>

How can we run these Junit tests in parallel without getting this error?