#DynamicPropertySource not being invoked (Kotlin, Spring Boot and TestContainers) - mongodb

Question

I'm trying to define a #TestConfiguration class that is executed once before all integration tests to run a MongoDB TestContainer in Kotlin in a Spring Boot project.
Here is the code:
import org.springframework.boot.test.context.TestConfiguration
import org.springframework.test.context.DynamicPropertyRegistry
import org.springframework.test.context.DynamicPropertySource
import org.testcontainers.containers.MongoDBContainer
import org.testcontainers.utility.DockerImageName
#TestConfiguration
class TestContainerMongoConfig {
companion object {
#JvmStatic
private val MONGO_CONTAINER: MongoDBContainer = MongoDBContainer(DockerImageName.parse("mongo").withTag("latest")).withReuse(true)
#JvmStatic
#DynamicPropertySource
private fun emulatorProperties(registry: DynamicPropertyRegistry) {
registry.add("spring.data.mongodb.uri", MONGO_CONTAINER::getReplicaSetUrl)
}
init { MONGO_CONTAINER.start() }
}
}
The issue seems to be that emulatorProperties method is not being called.
The regular flow should be that the container is started and then the properties are set.
The first step happens, the second does not.
I know there is an alternative for which I can do this configuration in each functional test class but I don't like it as it adds not needed noise to the test class.
For example, with a Java project that uses Postgres I managed to make it work with the following code:
import javax.sql.DataSource;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.boot.test.context.TestConfiguration;
import org.springframework.context.annotation.Bean;
import org.testcontainers.containers.PostgreSQLContainer;
import org.testcontainers.utility.DockerImageName;
#TestConfiguration
public class PostgresqlTestContainersConfig {
static final PostgreSQLContainer POSTGRES_CONTAINER;
private final static DockerImageName IMAGE = DockerImageName.parse("postgres").withTag("latest");
static {
POSTGRES_CONTAINER = new PostgreSQLContainer(IMAGE);
POSTGRES_CONTAINER.start();
}
#Bean
DataSource dataSource() {
return DataSourceBuilder.create()
.username(POSTGRES_CONTAINER.getUsername())
.password(POSTGRES_CONTAINER.getPassword())
.driverClassName(POSTGRES_CONTAINER.getDriverClassName())
.url(POSTGRES_CONTAINER.getJdbcUrl())
.build();
}
}
I'm trying to achieve the same thing but in Kotlin and using MongoDB.
Any idea on what may be the issue causing the #DynamicPropertySource not being called?

Answer 1

#DynamicPropertySource is part of the Spring-Boot context lifecycle. Since you want to replicate the Java setup in a way, it is not required to use #DynamicPropertySource. Instead you can follow the Singleton Container Pattern, and replicate it in Kotlin as well.
Instead of setting the config on the registry, you can set them as a System property and Spring Autoconfig will pick it up:
init {
MONGO_CONTAINER.start()
System.setProperty("spring.data.mongodb.uri", MONGO_CONTAINER.getReplicaSetUrl());
}

Answer 2

I was able to resolve similar problem in Groovy by:
Having static method annotated with #DynamicPropetySource directly in the test class (probably it would also work in superclass.
But I didn't want to copy the code into every test class that needs MongoDB.
I resolved the issue by using ApplicationContexInitializer
The example is written in groovy
class MongoTestContainer implements ApplicationContextInitializer<ConfigurableApplicationContext>{
static final MongoDBContainer mongoDBContainer = new MongoDBContainer(DockerImageName.parse("mongo:6.0.2"))
#Override
void initialize(ConfigurableApplicationContext applicationContext) {
mongoDBContainer.start()
def testValues = TestPropertyValues.of("spring.data.mongodb.uri="+ mongoDBContainer.getReplicaSetUrl())
testValues.applyTo(applicationContext.getEnvironment())
}
}
To make it complete, in the test class, you just need to add #ContextConfiguration(initializers = MongoTestContainer) to activate context initializer for the test.
For this you could also create custom annotation which would combine #DataMongoTest with previous annotation.

Answer 3

This solution works for me.
Method with #DynamicPropertySource is inside companion object(also added #JvmStatic) and added org.testcontainers.junit.jupiter.Testcontainers on the test class
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.ExtendWith
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.boot.jdbc.DataSourceBuilder
import org.springframework.boot.test.context.TestConfiguration
import org.springframework.context.annotation.Bean
import org.springframework.test.context.ContextConfiguration
import org.springframework.test.context.DynamicPropertyRegistry
import org.springframework.test.context.DynamicPropertySource
import org.springframework.test.context.junit.jupiter.SpringExtension
import org.testcontainers.containers.PostgreSQLContainer
import org.testcontainers.junit.jupiter.Container
import org.testcontainers.junit.jupiter.Testcontainers
import javax.sql.DataSource
#ExtendWith(SpringExtension::class)
#Testcontainers
#TestConfiguration
#ContextConfiguration(classes = [PostgresqlTestContainersConfig::class])
class PostgresqlTestContainersConfig {
#Autowired
var dataSource: DataSource? = null
#Test
internal fun name() {
dataSource!!.connection.close()
}
#Bean
fun dataSource(): DataSource? {
return DataSourceBuilder.create()
.username(POSTGRES_CONTAINER.getUsername())
.password(POSTGRES_CONTAINER.getPassword())
.driverClassName(POSTGRES_CONTAINER.getDriverClassName())
.url(POSTGRES_CONTAINER.getJdbcUrl())
.build()
}
companion object {
#JvmStatic
#Container
private val POSTGRES_CONTAINER: PostgreSQLContainer<*> = PostgreSQLContainer("postgres:9.6.12")
.withDatabaseName("integration-tests-db")
.withUsername("sa")
.withPassword("sa")
#JvmStatic
#DynamicPropertySource
fun postgreSQLProperties(registry: DynamicPropertyRegistry) {
registry.add("db.url") { POSTGRES_CONTAINER.jdbcUrl }
registry.add("db.user") { POSTGRES_CONTAINER.username }
registry.add("db.password") { POSTGRES_CONTAINER.password }
}
}
}