Spring Boot Testing

Introduction

This guide explains how to write integration tests for Flamingock when using Spring Boot with the @EnableFlamingock annotation.

With this setup:

• Flamingock is auto-configured using Spring Boot properties
• Dependencies like Kafka AdminClient or DynamoDbClient must be declared as Spring beans
• The change units are executed end-to-end using real systems (e.g., DynamoDB Local, Kafka, S3)

This test style is ideal for verifying that Flamingock interacts correctly with both its audit backend and any external systems.

Example: Modifying a Kafka topic and auditing to DynamoDB

Suppose you have a change unit that modifies a Kafka topic configuration:

@Change(id = "modify-topic-config", author = "dev-team")  // order extracted from filename
public class _0001__ModifyKafkaTopicConfig {

  @Apply
  public void apply(AdminClient adminClient) {
    Map<ConfigResource, Config> configs = Map.of(
      new ConfigResource(ConfigResource.Type.TOPIC, "orders"),
      new Config(List.of(new ConfigEntry("retention.ms", "86400000")))
    );

    adminClient.alterConfigs(configs).all().join();
  }

  @Rollback
  public void rollback(AdminClient adminClient) {
    Map<ConfigResource, Config> configs = Map.of(
      new ConfigResource(ConfigResource.Type.TOPIC, "orders"),
      new Config(List.of(new ConfigEntry("retention.ms", "604800000")))
    );

    adminClient.alterConfigs(configs).all().join();
  }
}

Writing the test

In this test, we’ll:

• Spin up Kafka and DynamoDB Local using Testcontainers
• Provide the required beans (AdminClient, DynamoDbClient) to Spring Boot
• Assert that the Flamingock change unit executed and was audited to DynamoDB

info

Flamingock requires DynamoDbClient and other injected services (like AdminClient) to be present in the Spring ApplicationContext. Spring Boot will auto-detect them if they are declared as @Beans.

@SpringBootTest
@Testcontainers
@EnableFlamingock(
    stages = {
        @Stage(location = "com.yourapp.changes")
    }
)
public class FlamingockSpringbootTest {

  static final KafkaContainer kafka = new KafkaContainer(DockerImageName.parse("confluentinc/cp-kafka:7.2.1"));
  
  static final GenericContainer<?> dynamoDb = new GenericContainer<>("amazon/dynamodb-local")
      .withExposedPorts(8000);

  @BeforeAll
  static void startContainers() {
    kafka.start();
    dynamoDb.start();
  }

  @AfterAll
  static void stopContainers() {
    kafka.stop();
    dynamoDb.stop();
  }

  @Bean
  public DynamoDbClient dynamoDbClient() {
    return DynamoDbClient.builder()
        .region(Region.US_EAST_1)
        .endpointOverride(URI.create("http://" + dynamoDb.getHost() + ":" + dynamoDb.getFirstMappedPort()))
        .build();
  }

  @Bean
  public AdminClient kafkaAdminClient() {
    var config = new Properties();
    config.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, kafka.getBootstrapServers());
    return AdminClient.create(config);
  }

  @Test
  void shouldExecuteChangeAndWriteAuditToDynamoDB() {
    DynamoDbClient client = dynamoDbClient();
    ScanResponse scan = client.scan(ScanRequest.builder()
        .tableName("flamingockAuditLog")
        .build());

    boolean changeExecuted = scan.items().stream()
        .anyMatch(item -> "modify-topic-config".equals(item.get("changeId").s())
                       && "EXECUTED".equals(item.get("state").s()));

    assertTrue(changeExecuted, "Audit log entry for executed change not found in DynamoDB");
  }
}

Advanced configuration

Flamingock can be configured using Spring Boot properties, either in your application.yaml or dynamically via @DynamicPropertySource.

This is especially useful for setting values like:

@DynamicPropertySource
static void overrideProperties(DynamicPropertyRegistry registry) {
  String endpoint = "http://" + dynamoDb.getHost() + ":" + dynamoDb.getFirstMappedPort();
  registry.add("flamingock.dynamodb.readCapacityUnits", () -> 5L);
  registry.add("flamingock.dynamodb.writeCapacityUnits", () -> 5L);
  registry.add("flamingock.dynamodb.autoCreate", () -> true);
  registry.add("flamingock.dynamodb.auditRepositoryName", () -> "flamingockAuditLog");
  registry.add("flamingock.dynamodb.lockRepositoryName", () -> "flamingockLock");
}

These properties allow Flamingock to connect to the appropriate DynamoDB instance and create its internal metadata tables automatically.

Best practices

• Declare all required dependencies (like DynamoDbClient, AdminClient, etc.) as Spring beans
• Use @DynamicPropertySource to inject dynamic config for local/test environments
• Validate both the external effect (Kafka, S3, etc.) and the audit record in the backend
• Use Testcontainers for isolation and reproducibility across environments
• Keep tests focused: use Spring Boot only when testing real integration scenarios (not just logic)