Declaring Containters as beans does not work as expected

[hantsy]

I followed the official guide to declare test containers as beans, the general method is working well.

@TestConfiguration(proxyBeanMethods = false)
static class MyTestConfig {

    @Bean
    @ServiceConnection
    PostgreSQLContainer<?> postgreSQLContainer() {
        return new PostgreSQLContainer<>(DockerImageName.parse("postgres:14"));
    }
}

But when adding the fallback method as described in https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#features.testing.testcontainers.at-development-time.dynamic-properties

@Bean
PostgreSQLContainer postgreSQLContainer(DynamicPropertyRegistry registry) {
    PostgreSQLContainer<?> PG_CONTAINER = new PostgreSQLContainer<>(DockerImageName.parse("postgres:14"));

    registry.add("spring.r2dbc.url", () -> "r2dbc:postgresql://" + PG_CONTAINER.getHost() + ":" + PG_CONTAINER.getFirstMappedPort() + "/" + PG_CONTAINER.getDatabaseName());
    registry.add("spring.r2dbc.username", PG_CONTAINER::getUsername);
    registry.add("spring.r2dbc.password", PG_CONTAINER::getPassword);

    return PG_CONTAINER;
}

It did not work as expected.

Reproduce example: https://github.com/hantsy/spring6-sandbox/blob/master/boot-data-r2dbc/src/test/java/com/example/demo/TestcontainersBeanExampleTests.java

1. Get a copy of https://github.com/hantsy/spring6-sandbox/blob/master/boot-data-r2dbc
2. Comment out the first method, and uncomment the second method in the above test.
3. Run the above test.

[snicoll]

So the error is:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'connectionFactory' defined in class path resource [org/springframework/boot/autoconfigure/r2dbc/ConnectionFactoryConfigurations$PoolConfiguration$PooledConnectionFactoryConfiguration.class]: Failed to instantiate [io.r2dbc.pool.ConnectionPool]: Factory method 'connectionFactory' threw exception with message: Failed to determine a suitable R2DBC Connection URL
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:659) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:647) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1332) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1162) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:560) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:520) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:973) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:941) ~[spring-context-6.0.9.jar:6.0.9]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:608) ~[spring-context-6.0.9.jar:6.0.9]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:733) ~[spring-boot-3.1.0.jar:3.1.0]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:435) ~[spring-boot-3.1.0.jar:3.1.0]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:311) ~[spring-boot-3.1.0.jar:3.1.0]
	at org.springframework.boot.test.context.SpringBootContextLoader.lambda$loadContext$3(SpringBootContextLoader.java:137) ~[spring-boot-test-3.1.0.jar:3.1.0]
	at org.springframework.util.function.ThrowingSupplier.get(ThrowingSupplier.java:58) ~[spring-core-6.0.9.jar:6.0.9]
	at org.springframework.util.function.ThrowingSupplier.get(ThrowingSupplier.java:46) ~[spring-core-6.0.9.jar:6.0.9]
	at org.springframework.boot.SpringApplication.withHook(SpringApplication.java:1405) ~[spring-boot-3.1.0.jar:3.1.0]
	at org.springframework.boot.test.context.SpringBootContextLoader$ContextLoaderHook.run(SpringBootContextLoader.java:545) ~[spring-boot-test-3.1.0.jar:3.1.0]
	at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:137) ~[spring-boot-test-3.1.0.jar:3.1.0]
	at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:108) ~[spring-boot-test-3.1.0.jar:3.1.0]
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:184) ~[spring-test-6.0.9.jar:6.0.9]
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:118) ~[spring-test-6.0.9.jar:6.0.9]
	... 72 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.r2dbc.pool.ConnectionPool]: Factory method 'connectionFactory' threw exception with message: Failed to determine a suitable R2DBC Connection URL
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:171) ~[spring-beans-6.0.9.jar:6.0.9]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:655) ~[spring-beans-6.0.9.jar:6.0.9]
	... 96 common frames omitted
Caused by: org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryOptionsInitializer$ConnectionFactoryBeanCreationException: Failed to determine a suitable R2DBC Connection URL
	at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryOptionsInitializer.connectionFactoryBeanCreationException(ConnectionFactoryOptionsInitializer.java:101) ~[spring-boot-autoconfigure-3.1.0.jar:3.1.0]
	at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryOptionsInitializer.initialize(ConnectionFactoryOptionsInitializer.java:57) ~[spring-boot-autoconfigure-3.1.0.jar:3.1.0]
	at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations.createConnectionFactory(ConnectionFactoryConfigurations.java:65) ~[spring-boot-autoconfigure-3.1.0.jar:3.1.0]
	at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations$PoolConfiguration$PooledConnectionFactoryConfiguration.connectionFactory(ConnectionFactoryConfigurations.java:97) ~[spring-boot-autoconfigure-3.1.0.jar:3.1.0]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:139) ~[spring-beans-6.0.9.jar:6.0.9]
	... 97 common frames omitted

Debugging, org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryOptionsInitializer#initialize is called with a null connectionDetails so we're trying to find an embedded datasource. I don't know enough about connection details to understand why that is.

[scottfrederick]

But when adding the fallback method as described in https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#features.testing.testcontainers.at-development-time.dynamic-properties ... It did not work as expected.

The section linked to here is for using Testcontainers at development time, when running an application using a test main method as described in the section just above.

In your sample, you are writing an integration test, which is a separate use case with different semantics for using DynamicPropertyRegistry. Using DynamicPropertyRegistry in integration tests requires the @DynamicPropertySource annotation on a static method, which is not supported on a @Bean method.

So, what you are trying to do in this test is not a supported configuration.

I've created #35856 to make the distinction between integration tests and development-time testing more clear in the documentation.

[jbeaken]

Thanks for this clarification, does that mean you cannot use @DynamicPropertySource when using development time and a test main method?

and if you have a container which doesn't support ServiceConnection, you are out of luck

[scottfrederick]

@jbeaken The Spring Boot documentation has as section that covers dynamic properties with Testcontainers at development time: https://docs.spring.io/spring-boot/docs/3.1.0/reference/htmlsingle/#features.testing.testcontainers.at-development-time.dynamic-properties

[hantsy]

I really did not understand the development time beans is not working in a test context.