使用带有 JUnit5 扩展的测试容器

Question

I using Spring boot and JUnit5 . My app work with several databases: MySQL , Clickhouse , etc.

For integration testing, I created JUnit5 Extensions:

public class ClickHouseTestContainersExtension implements BeforeAllCallback, BeforeTestExecutionCallback {

    public static final String IMAGE_NAME = "registry.mycomp.com/db/clickhouse-server:20.5.3.27";

    @Container
    private static final FixedHostPortGenericContainer<?> clickHouse = new FixedHostPortGenericContainer<>(IMAGE_NAME)
            .withCopyFileToContainer(MountableFile.forClasspathResource("dbInitScripts/init_clickhouse.sql"), "/docker-entrypoint-initdb.d/init_clickhouse.sql")
            .withMinimumRunningDuration(Duration.ofSeconds(7))
            .withFixedExposedPort(8124, 8123);

    @Override
    public void beforeAll(ExtensionContext extensionContext) {
        startContainerIfNeed();
    }

    @Override
    public void beforeTestExecution(ExtensionContext extensionContext) {
        startContainerIfNeed();
    }

    public void startContainerIfNeed() {
        if (!clickHouse.isRunning()) {
            log.info("ClickHouse container is not running! Started.....");
            clickHouse.start();
        }
    }
}

And MySQL:

public class MySQLTestContainersExtension implements BeforeAllCallback, BeforeTestExecutionCallback {

    private static final String IMAGE_NAME = "registry.mycomp.com/db/mariadb:10.4.11";

    @Container
    private static final FixedHostPortGenericContainer<?> mariaDb = new FixedHostPortGenericContainer<>(IMAGE_NAME)
            .waitingFor(new LogMessageWaitStrategy()
                    .withRegEx(".*ready for connections.*")
                    .withTimes(2)
                    .withStartupTimeout(Duration.of(3, MINUTES)))
            .withEnv("MYSQL_DATABASE", "db")
            .withEnv("MYSQL_USER", "sys")
            .withEnv("MYSQL_PASSWORD", "qwerty")
            .withEnv("MYSQL_ROOT_PASSWORD", "toor")
            .withEnv("MYSQL_RANDOM_ROOT_PASSWORD", "no")
            .withEnv("MYSQL_ALLOW_EMPTY_PASSWORD", "no")
            .withFixedExposedPort(33060, 3306)
            .withCopyFileToContainer(MountableFile.forClasspathResource("dbInitScripts/init_mysql.sql"),
                    "/docker-entrypoint-initdb.d/init_mysql.sql");

    @Override
    public void beforeAll(ExtensionContext extensionContext) {
        startContainerIfNeed();
    }

    @Override
    public void beforeTestExecution(ExtensionContext extensionContext) {
        startContainerIfNeed();
    }

    public void startContainerIfNeed() {
        if (!mariaDb.isRunning()) {
            log.info("MariaDB container is not running! Started.....");
            mariaDb.start();
        }
    }
}

And a number of other similar extensions.

I also have annotations:

@Target(value = {ElementType.TYPE, ElementType.METHOD})
@Retention(RUNTIME)
@ExtendWith({MySQLTestContainersExtension.class})
public @interface MySQL {
}

@Target(value = {ElementType.TYPE, ElementType.METHOD})
@Retention(RUNTIME)
@ExtendWith({ClickHouseTestContainersExtension.class})
public @interface ClickHouse {
}

@Target(value = {ElementType.TYPE, ElementType.METHOD})
@Retention(RUNTIME)
@ExtendWith({ClickHouseTestContainersExtension.class, MySQLTestContainersExtension.class,
        PostgreSQLTestContainersExtension.class, IgniteTestContainersExtension.class})
public @interface WithAllDatabases {
}

And, When I write some test, I use this extension:

    @Test
    @ClickHouse
    @DisplayName("Test connection ClickHouse with alive status")
    void testConnectionClickHouseWithAliveStatus() throws IOException {
        //smth
    }

    @Test
    @MySQL
    @DisplayName("Test connection MySQL with alive status")
    void testConnectionMariaDBWithAliveStatus() throws IOException {
        //smth
    }

  //etc

My connections properties, like username, password, url, store in database, not in apllication.yml. Any user of my system, can mannualy add new connection.

So I can't just use a spring mechanism like a @DynamicPropertySource .

Moreover, I can't get the generated random port from the extension in any way!

Therefore, I use a fixed port to create a set of test connections to the database raised in the content in tests!

Tell me if there is some approach that will allow you to use the JUnit 5 extension and use a random port. My task was to raise any database for a specific test by simply putting an annotation above this test.

Answer 1

I have a few questions

1. Does it work and you just want to use random ports instead of fixed ones or does it not work at all?
2. I think you follow the requirement too strictly. Just making as easy as placing one annotation on a test class/method is not the final purpose, since you don't have an API to work with your code. And you can't access anything (fields, methods) inside the extension class as I understand. I believe you might find it more convenient to either:

• have a singleton factory for each database container (turn startContainerIfNeed() into a factory method) and call MySQLTestContainersExtension.getContainer() when you need a container
• or make an abstract class out of extension classes and extend it in your test classes, in this case you can either keep a mariaDb variable static or make it a regular field and access via getter

Also @Container does not do anything in your case, you can read about it here