"Hello World" example on how to build and run tests with help of Docker.

2. Run automated tests in Docker
Oleksandr Metelytsia
5 December 2017, Kyiv

3. About me
Senior Test Automation Engineer in SoftServe
8+ years experience in software testing on different projects

4. Agenda
●Problem statement
●Docker to the rescue
●“Hello world” with Docker
●Tips and Tricks
●Q&A

5. Works on my machine (c)

6. ●OS differences between CI and local run
●python versions
●selenium and browser versions
●dependencies versions
●environment specific issues
●tools and libraries versions
●...
Possible reasons

7. Docker to the rescue
Docker containers wrap a piece of software in
a complete filesystem that contains
everything needed to run: code, runtime,
system tools, system libraries – anything that
can be installed on a server. This guarantees
that the software will always run the same,
regardless of its environment.

8. Docker
● docker != Virtual Machine like VirtualBox ov VMWare
● docker != configuration management like Chef or Puppet
● Encapsulates an app and all it dependencies including OS
into a single object called container
● Gives portable deployment across machines
● Works on Mac, Linux, Windows
● Multi-container orchestration with docker-compose

9. Docker diagram

10. Enough theory. Let’s code.
Step0.
Install docker and docker-compose

11. Hello world

12. Our dependencies

13. Dockerize the app

14. Build and test container

15. The dependency
Not so easy to setup Redis in an identical way every
time in a traditional environment.

16. But easy with Docker

17. Build and run

18. Test application

19. Create test case

20. Test dependencies: Firefox47 and requirements.txt
Test run:

21. Headless mode: xvfb
Xvfb or X virtual framebuffer
is a display server which
performs all graphical operations
in virtual memory without
showing any screen output.

22. Headless mode: xvfbwrapper
xvfbwrapper is a python wrapper for controlling Xvfb.

23. Let’s use xvfbwrapper

24. Create test environment

25. Build and test container

26. Test env Docker-compose yaml

27. Run pipeline

28. We are ready for Continuous Integration!
● very few commands to run in CI
● simple agents setup
● easy to maintain dependencies
● clear external services configuration
● the same local and CI envs
● fast dev-loop
● multi-environmental

29. Will this work on Windows7?

30. Tips & Tricks: Docker registry
The Registry is a stateless, highly scalable server side
application that stores and lets you distribute Docker images.
You could run your own private registry or use Docker Hub.

31. Tips & Tricks: CI your docker images
1.Put Dockerfiles under version control
2.Create CI plans to build and push images
3.Trigger plans on repo commit
4.Profit

32. Tips & Tricks: Official repositories

33. Thanks to Docker and Docker-Compose we automated:
● build of application (Dockerfile)
● deploy of a local environment (docker-compose.yml)
● build of a testing image (Dockerfile.test)
● tests execution (docker-compose.test.yml) for an application
Conclusions: 1

34. Advantages of using the docker-compose.test.yml file for testing:
● Automatable: the way a tool executes the docker-compose.test.yml is
independent of the application under test
● Light-weight: hundreds of external services can be deployed on a single
host, simulating complex test environments
● Agnostic: avoid CI provider lock-in, and your tests can run in any
infrastructure and on any OS which supports Docker
● Immutable: tests passing on your local machine will pass in your CI tool
Conclusions: 2

35. Conclusions: 3

36. Oleksandr Metelytsia
ometel@softserveinc.com
metelitsa.alexandr@gmail.com
Q&A