Integration and end-to-end testing with TestСontainers

Transcript

1. Integration and end-to-end testing with TestСontainers Nikolay Kuznetsov @nikolayk812 31 October 2019
2. About me • Go developer at Zalando Helsinki • Java developer at Infobip, DevExperts • C developer at Samsung, Motorola
3. Why integration testing?
4. Trade-offs Test Runtime
5. Basic integration test
6. Integration testing evolution • In-memory mocking • Local DBs • Vagrant • Docker, Docker Compose • Docker API
7. Docker advantages • 100% compatible database • Same version as production • Empty or known state
8. Start Docker containers for integration test • Shell scripts • Maven plugin • Docker Compose • Docker API • MiniKube, Kubernetes
9. Shell scripts
10. Maven plugins github.com/fabric8io/docker-maven-plugin
11. Docker Compose
12. Docker API docs.docker.com/engine/api/latest
14. TestContainers • github.com/testcontainers/testcontainers-java • Wraps docker-java library • Docker environment discovery • Host port randomization • Containers clean up on JVM shutdown • Readiness waiting strategies
15. As simple as static GenericContainer redis = new GenericContainer("redis:5.0.6") .withExposedPorts(6379); static PostgreSQLContainer postgres = new PostgreSQLContainer();
16. Docker environment discovery
17. Host port randomization • To prevent port conflicts • Enables parallel builds • API to get a host port
18. Containers cleanup https://github.com/testcontainers/moby-ryuk
19. Waiting strategies • Host port • HTTP • Log message • Docker healthcheck • Custom
20. Host port waiting strategy • Default: at first exposed port with timeout of 60s • Implementation checks both from outside and inside container
21. HTTP waiting strategy • Status & response body predicate
22. Demo I github.com/nikolayk812/vdc-tc-demo User Service
23. Demo recap • JUnit 5 integration via Extension API @TestContainers / @Container annotations • Modules ◦ wrappers on top of GenericContainer ◦ setters translated to containers environment variables
24. JUnit 5 extensions • Test execution lifecycle phases = extension points • Extension logic ◦ Implement interface(s) from o.j.j.api.extension.* ◦ Register with @ExtendsWith annotation
25. Modules • 14 database modules • MockServer • LocalStack = mocked AWS by Atlassian • Kafka, Pulsar, RabbitMQ • Toxiproxy
26. Demo II Extensions Modules
27. Demo III github.com/nikolayk812/vdc-tc-demo User Service Item Service
28. Why end-to-end testing? • Test business flows across multiple services • Regression when ◦ a new service introduced ◦ a legacy service removed
29. Testing environment cluster Spring Cloud Kubernetes
30. Test cluster for automated E2E tests • Unexpected versions of dependencies ◦ Teammates deploy from a development branch ◦ Pinging other teams to stabilize their test environment • Unexpected database states ◦ Care to clear data generated by a test run?
31. On-demand cluster for E2E tests • Locally and at CI machines • Needs time to spin up a new cluster • Resources: memory and CPU • How actually to do it?
32. Kubernetes for E2E tests
33. Non-Kubernetes for E2E tests • YAGNI = You aren’t gonna need it (Kubernetes for end-to-end tests) • Unless, you really want to test specific Kubernetes features or manifests • So, start services in containers within the same Docker network! (with TestContainers)
34. E2E setup Item Service User Service Spring Cloud Netflix Eureka
35. Docker network aliases item-alias :8084 user-alias :8083 postgres-alias :5432 redis-alias :6379 eureka-alias :8761
36. Spring Cloud Eureka service names item-eureka user-eureka eureka
37. Demo IV github.com/nikolayk812/vdc-tc-demo
39. E2E approach • Implement JUnit 5 extension for each service/database
40. E2E approach (2) • An extension implements BeforeAllCallback interface • Starts a corresponding container via TestContainers API • Configures it, provides a shared a network • Perform tests by calling endpoints via host ports
41. Demo V github.com/nikolayk812/vdc-tc-demo
42. Hints • Host port forwarding Testcontainers.exposeHostPorts() • Fixed host port for remote debug GenericContainer.addFixedExposedPort() •
43. Takeaways • https://testcontainers.org • Balance between flexibility, speed and features • Works on Mac, Linux, Windows • Great for integration tests • Possible to use for end-to-end tests
44. Mulțumesc! @nikolayk812 nikolayk812