Talk presented at Scrum Gathering Portugal 2016, in 2016/12/01

1. Containerizing Tests with
Docker 🐳🐙
Stefan Teixeira
@stefan_teixeira
stefanfk@gmail.com

2. • QA Automation Engineer @ Toptal
• Blogs: stefanteixeira.com.br (pt-br) /
stefanteixeira.com (en)
Contact:
• E-mail: stefanfk@gmail.com
• Twitter: twitter.com/stefan_teixeira
• LinkedIn: linkedin.com/in/stefanteixeira
• GitHub: github.com/stefanteixeira
• SlideShare: slideshare.net/stefanteixeira
About me

4. VMs x Containers
https://www.docker.com/whatisdocker

5. Why?

6. Why?
• Reprodutibility

7. Why?
• Reprodutibility

8. Why?
• Scalability

9. Why?
• Scalability

10. Why?
• Containers are (really) fast

11. Why?
• Containers are (really) fast

12. Docker Compose

13. Docker Compose
• Tool for defining and running multi-
container applications
https://docs.docker.com/compose/

14. Docker Compose
• Tool for defining and running multi-
container applications
• Previously known as Fig
https://docs.docker.com/compose/

15. Docker Compose
• Tool for defining and running multi-
container applications
• Previously known as Fig
• YAML ❤
https://docs.docker.com/compose/

16. Compose File

17. Containerizing Tests
with Docker

18. Containers != mini-VMs
https://twitter.com/rhein_wein/status/662995114235678720

19. Motivation

20. #1
If tests (except unit tests) are hard to run
locally, developers will not run them.
¯_(ツ)_/¯

21. #2
Sometimes, it’s really hard to configure a
test environment.
😫

22. “Docker delivers a predictable,
reproducible testing environment."
🐳❤
(Laura Frank, Codeship)

23. Examples

24. App A

25. App A
DB

26. App A
DB Mock Service

27. App A
DB Mock Service
API Tests

28. App A
DB Mock Service
API Tests
UI Tests

29. App A
DB Mock Service
API Tests
UI Tests
Security Tests

30. App A
DB Mock Service
API Tests
UI Tests
Security Tests
Smoke Tests

31. https://hub.docker.com/u/selenium/

32. Demo

33. Demo
• Very simple example, with three
containers:
• App (a REST API written in Node.js)
• DB (MongoDB database)
• API Tests (written with Supertest)
• https://github.com/stefanteixeira/demo-
testing-compose

34. Points of attention
• Logs

35. Points of attention
• Logs
• volumes or data containers

36. Points of attention
• Logs
• volumes or data containers
• Startup time

37. Points of attention
• Logs
• volumes or data containers
• Startup time
• wait-for-it, netcat (nc), curl, wait_for module
(Ansible)

38. Points of attention
• Building images

39. Points of attention
• Building images
• minimal base images: Alpine-linux, Phusion

40. Points of attention
• Building images
• minimal base images: Alpine-linux, Phusion
• automate the process

41. References
• “Stop being lazy and test your software”:
• https://www.youtube.com/watch?v=Mx1Il9wIepw
• http://www.slideshare.net/rheinwein/stop-being-lazy-and-test-
your-software
• https://hharnisc.github.io/2016/06/19/integration-testing-with-
docker-compose.html
• https://docs.docker.com/compose/startup-order/
• https://github.com/vishnubob/wait-for-it
• https://www.ansible.com/blog/six-ways-ansible-makes-docker-
compose-better

42. Stefan Teixeira
@stefan_teixeira
stefanfk@gmail.com
Thanks!