Setup testcontainers for micronaut for mongodb

Thats helped me in in order to run Testcontainers with micronauts in Kotlin.

import a.b.c.model.NewOffer
import a.b.c.model.QuantityType
import io.micronaut.test.extensions.junit5.annotation.MicronautTest
import io.micronaut.test.support.TestPropertyProvider
import org.assertj.core.api.Assertions.assertThat
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.TestInstance
import org.testcontainers.containers.MongoDBContainer
import org.testcontainers.junit.jupiter.Testcontainers
import javax.inject.Inject

@Testcontainers
@MicronautTest()
@TestInstance(TestInstance.Lifecycle.PER_CLASS)
internal class OfferRepositoryTest() : TestPropertyProvider {

    @Inject
    private lateinit var offerRepository: OfferRepository

    private val mongoDBContainer: MongoDBContainer = MongoDBContainer("mongo:4").apply { start() }

    @Test
    internal fun getEmptyOffers() {
        val find = offerRepository.find()
        assertThat(find).isEmpty()
    }

    override fun getProperties(): MutableMap<String, String> {
        return mutableMapOf(
                "MONGO_HOST" to mongoDBContainer.containerIpAddress,
                "MONGO_PORT" to "${mongoDBContainer.getMappedPort(27017)}"
        )
    }
}

and the src/main/resources/application.yml looks as generated by micronaut

mongodb:
  connection-pool:
    max-size: 20
  uri: mongodb://${MONGO_HOST:localhost}:${MONGO_PORT:27017}