Slides for the "Rapid Development With Docker Compose" talk as presented at Kiwi Pycon 2017. https://www.youtube.com/watch?v=o6SScget37w

1. Rapid Development
With Docker Compose

2. Justin Crown
https://github.com/mrname/

3. https://github.com/
mrname/kiwi-pycon-2017/

5. Workflow Requirements
• Portable (various operating systems)
• Easy to operate
• Ability to rapidly iterate code changes
• Minimal setup

6. Objective
• Deploy a full stack Django Rest Framework
application with:
• Nginx reverse proxy
• PostgreSQL
• Django-Q for task scheduling with redis as a
backend

9. docker build
(run commands in
dockerfile,
create image)
Docker
Image
docker run
Docker
Container
(instance of
image)

10. Base Image
Dockerfile

11. Do not buffer output
Dockerfile

12. Copy all files from CWD of
host to /src of container
Dockerfile

13. This is now the root of all commands
Dockerfile

14. Install requirements
Dockerfile

15. Expose application port in container
Dockerfile

17. Docker Compose Version
Nginx Service
Postgres Service

18. Image Based Service
Build Based Service
Image Used To Create Container
Directory of Dockerfile
Command to run in container

20. Load Env Vars From These Files

21. When Should The Container Restart?

22. Inline Environment Variables

23. Mount “.” of the host to “/src/“ of the container

24. Wait for these containers to start before we start this one

25. Forward port 8000 of host to port 8000 of container

26. docker-compose ps
List Running Containers

27. docker-compose up
Bring up containers, building or pulling as necessary

28. Now we have… things!

29. docker-compose exec
Execute commands on running containers

30. docker-compose run
Execute a single command in a ONE OFF container

33. Magical Hostname… Thanks Docker Compose!

35. Magical Hostname… Thanks Docker Compose!

36. Tips, Tricks, Caveats
Container LifeCycle
docker-compose start/stop/restart
Affects the EXISTING CONTAINER. NOTHING IS
CHANGED

37. Tips, Tricks, Caveats
Container LifeCycle
docker-compose up
• Recreates container if something has changed
• Avoid recreating dependent services with --no-deps
• Force build with --build
• Force recreate with --force-recreate

38. Tips, Tricks, Caveats
Container LifeCycle
docker-compose build
• Rebuilds the image, using cached layers if available. Force a completely fresh
build with --no-cache
• DOES NOT pull your base image if it exists. Force pull base with --pull

39. Tips, Tricks, Caveats
Container LifeCycle
docker-compose pull
• Exactly what you expect........

40. Tips, Tricks, Caveats
Multiple Services With Same Built Image
Build + Image means that the built image
will be tagged with the value of
the “image” argument

41. Tips, Tricks, Caveats
Networks
Source: https://docs.docker.com/compose/networking/#specify-custom-networks

42. Tips, Tricks, Caveats
Scaling and Load Balancing

43. Tips, Tricks, Caveats
Scaling and Load Balancing
Round Robin DNS FOR FREE!

44. Tips, Tricks, Caveats
Application Configuration (Environment Variables)

45. Tips, Tricks, Caveats
Application Configuration (Environment Variable Files)

46. Tips, Tricks, Caveats
Application Configuration (Inline Environment Variables)
These variables take precedence over the env file!
Provide key and value
Infer value from shell

48. • Remove volumes that do not require
persistence (i.e. - code)
• Use networks
• Remove extraneous port bindings
• Use prod environment variables
• Use prod WSGI server
• Use built image instead of building on host

49. Release Overview
• docker-compose build (or pull)
• docker-compose scale (updated service only)
• find old container (docker ps)
• stop old container
• remove old container
• docker-compose scale back down

51. Growing Up
• Kubernetes
• Docker Swarm
• Apache Mesos
• Amazon ECS
• Packer