Devoxx MA: Testcontainers deep dive

Transcript

1. Testcontainers Integration testing without the hassle Sergei @bsideup Egorov
2. About me • Testcontainers co-maintainer • Staff Engineer at Pivotal’s Spring R&D, working on Project Reactor ⚛ • Berlin Spring User Group co-organizer • Developer tools geek @bsideup
3. Integration testing?
4. @bsideup
5. @bsideup
6. https://martinfowler.com/bliki/IntegrationTest.html @bsideup
7. https://martinfowler.com/bliki/IntegrationTest.html @bsideup
8. https://martinfowler.com/bliki/IntegrationTest.html @bsideup
9. https://labs.spotify.com/2018/01/11/testing-of-microservices/ “Microservices Testing Honeycomb” @bsideup
10. https://labs.spotify.com/2018/01/11/testing-of-microservices/ “Microservices Testing Honeycomb” @bsideup We’re here
11. Some signs of having Integrated Tests are: • We spin up other services in a local testing environment • We test against other services in a shared testing environment • Changes to your system breaks tests for other systems https://labs.spotify.com/2018/01/11/testing-of-microservices/ @bsideup
12. So…
 Integration testing.
13. Verify how your software product will behave in real- world conditions
14. Isolated from other system components to avoid false negatives
15. Real: databases, file systems, network interfaces, …
16. Grey box testing - we know some inner details, but mostly use public APIs
18. Unit testing • Simulation tests are green, yay! • Everything is mocked • DB is written by others, why should I test it? @bsideup
19. Integration testing https://commons.wikimedia.org/wiki/File:Cd4007.jpg • Jeez, how did it passed the Unit testing? • Is it a smoke? @#$%! YES IT IS! • Who knew that 100w soldering gun was a bit too powerful for it? @bsideup
20. System testing https://commons.wikimedia.org/wiki/File:UART_8250_Microchip.jpg • Takes a lot of time to solder • “Oh no, the power bus is too far away from my microchip!” • Interference between the components @bsideup
21. Production @bsideup
22. Integration testing Real-world, but isolated testing Spot the issues before the real environment Can be run during the development You have to start real databases Should be cross-platform Slower than Unit testing Pros Cons @bsideup
23. Integration testing transformation @bsideup
24. Mocking Integration testing transformation @bsideup
25. Mocking Local DBs Integration testing transformation @bsideup
26. Mocking Local DBs VMs
 (Vagrant) Integration testing transformation @bsideup
27. Mocking Local DBs VMs
 (Vagrant) Docker Integration testing transformation @bsideup
29. Abstraction layer
30. CI friendly
31. Cross-platform
32. Mocking Local DBs VMs
 (Vagrant) Docker Integration testing transformation @bsideup
33. Mocking Local DBs VMs
 (Vagrant) Docker Fig
 (aka Docker Compose) Integration testing transformation @bsideup
34. Docker Compose FTW! redis: image: redis ports: - "6379:6379" postgres: image: postgres ports: - "5432:5432" elasticsearch: image: elasticsearch:5.0.0 ports: - "9200:9200" @bsideup
35. But…
36. Declarative YAML redis: image: redis ports: - "6379:6379" postgres: image: postgres ports: - "5432:5432" elasticsearch: image: elasticsearch:5.0.0 ports: - "9200:9200" @bsideup
37. No ports randomization redis: image: redis ports: - "6379:6379" postgres: image: postgres ports: - "5432:5432" elasticsearch: image: elasticsearch:5.0.0 ports: - "9200:9200" @bsideup
38. Container per test? redis: image: redis ports: - "6379:6379" postgres: image: postgres ports: - "5432:5432" elasticsearch: image: elasticsearch:5.0.0 ports: - "9200:9200" @bsideup
39. IDE integration? @bsideup
40. Mocking Local DBs VMs
 (Vagrant) Docker Fig
 (aka Docker Compose) Integration testing transformation @bsideup
41. Mocking Local DBs VMs
 (Vagrant) Docker Fig
 (aka Docker Compose) Docker API Integration testing transformation @bsideup
42. Fighting with Docker environment
43. There is no place like
44. There is no place like … unless there is
45. Can we improve that?
47. Testcontainers • Created by Richard North in 2015 • github.com/testcontainers/testcontainers-java • Wraps docker-java library • Docker environment discovery (Win, Mac, Linux) • Containers cleanup on JVM shutdown @bsideup
48. As simple as PostgreSQLContainer postgresql = new PostgreSQLContainer() GenericContainer redis = new GenericContainer("redis:3") .withExposedPorts(6379) @bsideup
49. Users
50. @bsideup
51. Use case: testing of microservices • REST service • Java, Spring Boot • Redis, Kafka and PostgreSQL • Calls some other micro-services @bsideup
52. @RunWith(SpringRunner.class) @SpringBootTest(webEnvironment = RANDOM_PORT) @ContextConfiguration(initializers = Initializer.class) public abstract class AbstractIntegrationTest { @ClassRule public static GenericContainer redis = new GenericContainer("redis:3.0.6") .withExposedPorts(6379); @ClassRule public static MockServerContainer mockServer = new MockServerContainer(); } @bsideup
53. @RunWith(SpringRunner.class) @SpringBootTest(webEnvironment = RANDOM_PORT) @ContextConfiguration(initializers = Initializer.class) public abstract class AbstractIntegrationTest { @ClassRule public static GenericContainer redis = new GenericContainer("redis:3.0.6") .withExposedPorts(6379); @ClassRule public static MockServerContainer mockServer = new MockServerContainer(); } Still using all the Spring goodies! @bsideup
54. @RunWith(SpringRunner.class) @SpringBootTest(webEnvironment = RANDOM_PORT) @ContextConfiguration(initializers = Initializer.class) public abstract class AbstractIntegrationTest { @ClassRule public static GenericContainer redis = new GenericContainer("redis:3.0.6") .withExposedPorts(6379); @ClassRule public static MockServerContainer mockServer = new MockServerContainer(); } External dependencies @bsideup
56. Demo
57. Takeaways • https://testcontainers.org • Works on Linux, Mac and Windows • …including CIs like Jenkins, Travis, CircleCI, GH Actions, Azure Pipelines, … • Provides a great balance between 
 flexibility, usability, speed and features
 @bsideup
58. Questions?
59. @bsideup bsideup
60. https://commons.wikimedia.org/wiki/File:Thats_all_folks.svg