TestContainers + JUnit 5 = elegant integration and e2e tests for microservices

Transcript

1. TestContainers + JUnit 5 = elegant integration and e2e tests for microservices Nikolay Kuznetsov @nikolayk812 TESTING UNITED Vienna, 7 November 2019
2. About me • Go developer at Zalando Helsinki • Java developer at Infobip, DevExperts • C developer at Samsung, Motorola
3. My testing experience • Unit, integration and end-to-end automated tests development • Various organizational structures ◦ Separate QA teams ◦ QA engineers in a dev team ◦ No QA teams/engineers at all
4. Key points • Targeting automated testing • Examples and demos in Java: TestContainers-Java, JUnit 5, Spring Boot • Principles are language-agnostic
5. Why integration testing?
6. 2 unit tests, 0 integration tests
7. Tests trade-offs
9. Basic integration test
10. Integration testing evolution • In-memory mocking • Local DBs • Vagrant • Docker, Docker Compose • Docker API
11. Docker architecture
12. How to start a container for test? • Shell scripts • Maven plugin • Docker Compose • Docker API • MiniKube, Kubernetes
13. Shell scripts
14. Maven plugin github.com/fabric8io/docker-maven-plugin
15. Docker Compose
16. Docker API
18. TestContainers flavors
19. TestContainers Java • github.com/testcontainers/testcontainers-java • Wraps docker-java library • Docker environment autodiscovery • Host port randomization • Containers clean up on JVM shutdown • Readiness waiting strategies
20. As simple as var redis = new GenericContainer("redis:5.0.5") .withExposedPorts(6379); var postgres = new PostgreSQLContainer();
21. Docker environment autodiscovery
22. Host port randomization • Prevents port conflicts • Enables parallel CI builds • API to get an actual host port
23. Containers cleanup github.com/testcontainers/moby-ryuk
24. Readiness waiting strategies • Host port • HTTP status/body • Log message • Docker healthcheck • Combination of above • Custom
25. Demo setup User Service
26. Demo scenario User Service INSERT INTO SELECT FROM
27. Demo github.com/nikolayk812/tu-tc-demo
28. Demo recap • JUnit 5 integration via Extension API ◦ @TestContainers / @Container • TestContainers Modules ◦ 14 databases ◦ Kafka, MockServer, LocalStack, ToxiProxy, etc
29. JUnit 5 Extensions • Customizable extension points: ◦ Life-cycle phases ◦ Parameter resolution ◦ Conditional execution, etc • Extension logic registered with @ExtendsWith
30. github.com/nikolayk812/tu-tc-demo Demo-2: setup User Service
31. Demo-2: scenario User Service POST /users GET /user/<id>
32. Demo-2: Docker network User Service user-alias: 8083 postgres-alias: 5432 localhost: 32812
33. Demo 2 github.com/nikolayk812/tu-tc-demo
34. Demo-2: recap • Docker network and alias
35. Why end-to-end testing? • Business flows across multiple services • Regression, when ◦ + new service ◦ - legacy service
36. Testing/staging deployed cluster Spring Cloud Kubernetes
37. Testing against a deployed cluster • Deploy a new service version to the cluster? • Unexpected versions of dependent services • Unexpected database states ◦ Care to clear after the test? • Parallel CI builds?
38. On-demand cluster for E2E tests + Locally and at CI machines + Control over dependent services versions - Time to start all containers - Resources: memory and CPU How to do it?
39. Kubernetes for E2E tests?
40. Kubernetes for E2E tests - YAGNI TestContainers + Docker network!
41. E2E test setup User Service Item Service
42. Takeaways • https://testcontainers.org • Balance between flexibility, speed and features • Works on Mac, Linux, Windows
43. QUESTIONS ?