JUnit5: Start containers concurrently

When using Testcontainers in combination with JUnit5 using @Testcontainers and @Container all the containers are started sequentially.

Especially when there are multiple containers involved it could save some time to start them in parallel.

This feature request is about facilitating the concurrent start of containers.

[40rn05lyv]

It’s possible to use both @Container annotation with a parallel approach. You can implement org.testcontainers.lifecycle.Startable interface that would have several containers inside it. Like this:

public class ParallelContainers implements org.testcontainers.lifecycle.Startable {

    private final GenericContainer container1 = ...;
    private final GenericContainer container2 = ...;

    @Override
    public void start() {
        Stream.of(this.container1, this.container2).parallel().forEach(GenericContainer::start);
    }

    @Override
    public void stop() {
        Stream.of(this.container1, this.container2).parallel().forEach(GenericContainer::stop);
    }

}

And then just use @Container ParallelContainers containers in test classes.

[Olex1313]

Well sorry for long thinking about the problem, maybe it instead could be a flag on @Container annotation, so in the https://github.com/testcontainers/testcontainers-java/blob/main/modules/junit-jupiter/src/main/java/org/testcontainers/junit/jupiter/TestcontainersExtension.java, we might split containers into 2 groups every time we have to start it, and as you said start ones with the flag with sample of code like this

parallelContainers.parallel().forEach(GenericContainer::start);

?