SpringBootTest, Testcontainers, container start up - Mapped port can only be obtained after the container is started - spring-boot

Question

I am using docker/testcontainers to run a postgresql db for testing. I have effectively done this for unit testing that is just testing the database access. However, I have now brought springboot testing into the mix so I can test with an embedded web service and I am having problems.
The issue seems to be that the dataSource bean is being requested before the container starts.
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [com/myproject/integrationtests/IntegrationDataService.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Mapped port can only be obtained after the container is started
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Mapped port can only be obtained after the container is started
Caused by: java.lang.IllegalStateException: Mapped port can only be obtained after the container is started
Here is my SpringBootTest:
#RunWith(SpringJUnit4ClassRunner.class)
#SpringBootTest(classes = {IntegrationDataService.class, TestApplication.class},
webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class SpringBootTestControllerTesterIT
{
#Autowired
private MyController myController;
#LocalServerPort
private int port;
#Autowired
private TestRestTemplate restTemplate;
#Test
public void testRestControllerHello()
{
String url = "http://localhost:" + port + "/mycontroller/hello";
ResponseEntity<String> result =
restTemplate.getForEntity(url, String.class);
assertEquals(result.getStatusCode(), HttpStatus.OK);
assertEquals(result.getBody(), "hello");
}
}
Here is my spring boot application referenced from the test:
#SpringBootApplication
public class TestApplication
{
public static void main(String[] args)
{
SpringApplication.run(TestApplication.class, args);
}
}
Here is the IntegrationDataService class which is intended to startup the container and provide the sessionfactory/datasource for everything else
#Testcontainers
#TestInstance(TestInstance.Lifecycle.PER_CLASS)
#EnableTransactionManagement
#Configuration
public class IntegrationDataService
{
#Container
public static PostgreSQLContainer postgreSQLContainer = (PostgreSQLContainer) new PostgreSQLContainer("postgres:9.6")
.withDatabaseName("test")
.withUsername("sa")
.withPassword("sa")
.withInitScript("db/postgresql/schema.sql");
#Bean
public Properties hibernateProperties()
{
Properties hibernateProp = new Properties();
hibernateProp.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");
hibernateProp.put("hibernate.format_sql", true);
hibernateProp.put("hibernate.use_sql_comments", true);
// hibernateProp.put("hibernate.show_sql", true);
hibernateProp.put("hibernate.max_fetch_depth", 3);
hibernateProp.put("hibernate.jdbc.batch_size", 10);
hibernateProp.put("hibernate.jdbc.fetch_size", 50);
hibernateProp.put("hibernate.id.new_generator_mappings", false);
// hibernateProp.put("hibernate.hbm2ddl.auto", "create-drop");
// hibernateProp.put("hibernate.jdbc.lob.non_contextual_creation", true);
return hibernateProp;
}
#Bean
public SessionFactory sessionFactory() throws IOException
{
LocalSessionFactoryBean sessionFactoryBean = new LocalSessionFactoryBean();
sessionFactoryBean.setDataSource(dataSource());
sessionFactoryBean.setHibernateProperties(hibernateProperties());
sessionFactoryBean.setPackagesToScan("com.myproject.model.entities");
sessionFactoryBean.afterPropertiesSet();
return sessionFactoryBean.getObject();
}
#Bean
public PlatformTransactionManager transactionManager() throws IOException
{
return new HibernateTransactionManager(sessionFactory());
}
#Bean
public DataSource dataSource()
{
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName(postgreSQLContainer.getDriverClassName());
dataSource.setUrl(postgreSQLContainer.getJdbcUrl());
dataSource.setUsername(postgreSQLContainer.getUsername());
dataSource.setPassword(postgreSQLContainer.getPassword());
return dataSource;
}
}
The error occurs on requesting the datasource bean from the sessionFactory from one of the Dao classes before the container starts up.
What the heck am I doing wrong?
Thanks!!!

Answer 1

The reason for your java.lang.IllegalStateException: Mapped port can only be obtained after the container is started exception is that when the Spring Context now gets created during your test with #SpringBootTest it tries to connect to the database on application startup.
As you only launch your PostgreSQL inside your IntegrationDataService class, there is a timing issue as you can't obtain the JDBC URL or create a connection on application startup as this bean is not yet properly created.
In general, you should NOT use any test-related code inside your IntegrationDataService class. Starting/stopping the database should be done inside your test setup.
This ensures to first start the database container, wait until it's up- and running, and only then launch the actual test and create the Spring Context.
I've summarized the required setup mechanism for JUnit 4/5 with Testcontainers and Spring Boot, that help you get the setup right.
In the end, this can look like the following
// JUnit 5 example with Spring Boot >= 2.2.6
#Testcontainers
#SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
public class ApplicationIT {
#Container
public static PostgreSQLContainer postgreSQLContainer = new PostgreSQLContainer()
.withPassword("inmemory")
.withUsername("inmemory");
#DynamicPropertySource
static void postgresqlProperties(DynamicPropertyRegistry registry) {
registry.add("spring.datasource.url", postgreSQLContainer::getJdbcUrl);
registry.add("spring.datasource.password", postgreSQLContainer::getPassword);
registry.add("spring.datasource.username", postgreSQLContainer::getUsername);
}
#Test
public void contextLoads() {
}
}