Reusable containers and Gradle parallel test execution

[keith-miller]

First off thank you for such a great library!

We have a question about reusing containers. We're currently switching our Gradle builds over to parallel mode, and we are noticing that we're having issues with our generic Redis container being started multiple times. Here is the init code block:

abstract class AbstractIntegrationTest {
    companion object {
        val crdb = CockroachContainer(DockerImageName.parse("cockroachdb/cockroach:v21.1.5")).apply {
            withInitScript("db/init.sql")
            withReuse(true)
            withLabel("reuse.UUID", "01ff0fcc-3773-4971-8240-0af588ec35cf")
            start()
        }

        val rabbitmq = RabbitMQContainer(DockerImageName.parse("rabbitmq:3.8.12")).apply {
            withReuse(true)
            withLabel("reuse.UUID", "758c493d-ed7f-4309-8571-bebec3fca031")
            start()
        }

        val redis = GenericContainer<Nothing>(DockerImageName.parse("redis:latest")).apply {
            withExposedPorts(6379)
            withReuse(true)
            withLabel("reuse.UUID", "99a67fab-7ed0-4041-9fbb-dff45015a62a")
            start()
        }
    }
}

Then, we see during the run:

and after:

The CockroachDB/RabbitMQ seem to handle the startup race condition fine and only start one container. The Redis GenericContainer starts multiple times. So, is there a way to handle the startup race condition for the Redis container?

Thanks!

[bsideup]

@keith-miller it looks like, since your tests are executed in parallel, they all fail to find a running container and decide to start one.

There isn't much that Testcontainers can do about it (we have no awareness of other Testcontainers sessions on the same machine, at least not yet), but you can workaround it by running a single job that would start these before your parallel test sessions, so that every parallel session will be able to discover running containers.

[keith-miller]

Right, makes sense. I can control the start/stop from Gradle. Is there something in the docs about setting up a test container object with an already running container? Just wondering what the best way to get the mapped ports back from test containers I start from Gradle.

Thanks!

[esfomeado]

Any update on this?