Hi! If I need to configure an instance of a testcontainer for postgres, where whould I do that? It s...

# kotest

[dave08]

Hi! If I need to configure an instance of a testcontainer for postgres, where whould I do that? It seems like Startable.perProject(...) takes a name param, but doesn't work for a customized container...

[dave08]

Does it just use the containerName internally in Kotest? And the startable is just any already configured container?

[dave08]

@sam, How would I use the extension for this:

class Postgresql: PostgreSQLContainer<Postgresql>("postgres:9.6")  {
	companion object {
		private lateinit var instance: Postgresql
		fun start() {
			if (!Companion::instance.isInitialized) {
				// Reuse container between tests instead of starting a new one per execution
				instance = Postgresql()
				instance
					.withReuse(true)
					.withUsername("...")
					.withDatabaseName("...")
					.withInitScript("db-structure.sql")
					.start()

				System.setProperty("datasources.default.url", instance.jdbcUrl)
				System.setProperty("datasources.default.username", instance.username)
				System.setProperty("datasources.default.password", instance.password)
			}
		}

		fun stop() {
			if (Companion::instance.isInitialized) {
				instance.stop()
			}
		}
	}
}

[dave08]

I don't see any real example in the docs or the tests...

[sam]

Have you looked at this https://kotest.io/docs/extensions/test_containers.html

[dave08]

There it has GenericContainer<Nothing>("redis:5.0.3-alpine") ... but not using configuration like I did in the previous code.

[dave08]

Dbs are more complicated, and micronaut needs those system props to be able to communicate with the db...

[sam]

All kotest is doing is calling start / stop as part of the test lifecycle, so you should be able to create any container you want ,with any config you want, and then pass it into listener(mycontainer.perTest())

[dave08]

[sam]

what is perProject

[dave08]

fun <T : Startable> T.perProject(containerName: String): StartablePerProjectListener<T> = StartablePerProjectListener<T>(this, containerName)

In the kotest extenstion lib

[sam]

ok let me check

[sam]

I'll get it working, you update the docs

[sam]

deal ? 😛

[dave08]

It seems like the problem is that Postgresql is a class... if I pass it's instance in the companion object, it would be ok... but that's a pretty messy way to configure an extension like this 🤒

[sam]

TestContainers is an amazing project, but it has the weirdiest type variance I've ever seen.

[sam]

you have to subclass it

[sam]

so do this

[sam]

class PostgresTest : FunSpec() {
   init {

      class MyPostgreSQLContainer : PostgreSQLContainer<MyPostgreSQLContainer>("somedocker")

      val postgres = MyPostgreSQLContainer()
         .withReuse(true)
         .withUsername("...")
         .withDatabaseName("...")
      
      listener(postgres.perProject("listener-name"))

      test("with postgres container") {

      }
   }
}

[sam]

Look forward to your pr 😉

[dave08]

In the example, you had GenericContainer<Nothing>(...), that can't be used here too? PostgreSQLContainer<Nothing>("somedocker")?

[sam]

Not if you want to set config because it uses the type parameter as the return type

[sam]

Which is why you need to subclass it, because what they've done doesn't work in kotlin

[dave08]

Oh... so really to make this cleaner, the only way would be to provide a subclass for all the available types... 🤕.

Thanks for the help! I'll have to think out what can be improved in a PR...

[sam]

the docs would be enough 🙂

[dave08]

What about the listener order? Is there a guarantee that a listener put earlier in the ProjectConfig gets loaded first? I see that in the testcontainers listener, it's using withContext, does that mean they get loaded in parallel?

[sam]

they will run sequentially, in the order they are defined in the test class

[sam]

ones defined outside the test class may run before or after

[dave08]

I mean the ones in the global config?

[sam]

They will run in order but it's undefined if all of those run before all the ones in the test

[sam]

You could check the source but there's no guarantees it won't move about

[dave08]

It might be nice to have some kind of priority setting here, no?

[sam]

yep

[sam]

If you can think of some suitable syntax please create an issue and we can put it in 4.5

[dave08]

Micronaut isn't too forgiving when things don't come up on time... I'll try to give it a thought, thanks!

[thanksforallthefish]

we went for

class ProjectConfig : AbstractProjectConfig() {
  override fun listeners() = listOf(
    StartablePerProjectListener(
      SpringPostgreSQLContainer("10").withNetwork(Network.SHARED)
        .withNetworkAliases("db"), "postgres"
    ),
    StartablePerProjectListener(
      SpringLocalstackContainer("0.11.2").withServices(LocalStackContainer.Service.S3)
        .withNetwork(Network.SHARED)
        .withNetworkAliases("s3"), "s3"
    ),
    SpringListener
  )
}

class SpringLocalstackContainer(tag: String) :
  LocalStackContainer(DockerImageName.parse("localstack/localstack").withTag(tag)) {
  override fun start() {
    super.start()
    System.setProperty("S3_ENDPOINT", getEndpointConfiguration(Service.S3).serviceEndpoint)
    System.setProperty("S3_REGION", region)
    System.setProperty("AWS_ACCESS_KEY", accessKey)
    System.setProperty("AWS_SECRET_KEY", secretKey)
  }

}

class SpringPostgreSQLContainer(tag: String) :
  PostgreSQLContainer<SpringPostgreSQLContainer>(DockerImageName.parse(IMAGE).withTag(tag)) {
  override fun start() {
    super.start()
    System.setProperty("DB_URL", "jdbc:postgresql://${connectionString()}")
    System.setProperty("DB_USERNAME", username)
    System.setProperty("DB_PASSWORD", password)
    System.setProperty("spring.flyway.schemas", databaseName)
  }

  private fun connectionString() = "$host:$firstMappedPort/$databaseName"
}

but we have a very simple project with just this 2 containers as dependencies for now

got hit by the weird type variance as well: https://github.com/testcontainers/testcontainers-java/issues/318

[dave08]

Good point @thanksforallthefish... the system props need to be declared after the container starts... I ended up with altering the startable project listener:

class StartablePerProjectListener<T : Startable>(
	val startable: T,
	val containerName: String,
	val afterStart: (T.() -> Unit)?
) : TestListener,
	ProjectListener {
	override val name = containerName
	private val testLifecycleAwareListener = TestLifecycleAwareListener(startable)

	override suspend fun beforeProject() {
		withContext(<http://Dispatchers.IO|Dispatchers.IO>) {
			startable.start()
			afterStart?.invoke(startable)
		}
	}
...

[dave08]

But that's still not so clean...

[sam]

You could have two listeners, one to start the container, and one to configure it, and run them in order.

[dave08]

Yeah, but that gets a bit messy when managing multiple containers...