Docker swarm workshop

1. DOCKER
SWARM
An introduction
Matthias Noback
@matthiasnoback
info@matthiasnoback.nl

2. some-other-machine
DOCKER
A daemon and a client
Docker
daemon
client
container container container

3. SWARM
Nodes running a Docker daemon "in Swarm mode"
Swarm
Node Node Node

4. CLI TOOLS
docker-machine and docker

5. CLUSTER MANAGEMENT
Easily add new nodes to a cluster

6. CONFIGURATION
Docker Compose file (some keys are ignored)
# docker-compose.yml
version: '3'
services:
...

7. SCALING
Configure the number of tasks (replicas)
Service (recipe)
Service_Task_1 Service_Task_2

8. SERVICE DISCOVERY & LOAD
BALANCING
Divide incoming requests over available tasks
Service_Task_1:80
(10.0.0.23)
Service_Task_2:80
(10.0.0.24)
service:80

9. Host 1
MULTI-HOST NETWORKING
Secure, even across data centers
Node Node
Host 2
Node Node
Swarm

10. NODES
No login required
Use docker-machine to provision them
Use docker to deploy to them

11. MANAGERS AND WORKERS
Resilient
Manager
Worker Worker
Manager
Worker

12. ASSIGNMENTS/
ALL.MD
Playing with Swarm
https://github.com/matthiasnoback/docker-swarm-workshop/

13. CLOSING
NOTES
Considerations

14. EVERYTHING IS AWESOME

15. STATEFUL SERVICES
Use shared state (database)
Maybe use hosted solutions

16. DISPOSABLE INFRASTRUCTURE
Make all setup automated

17. BEST PRACTICES
https://docs.docker.com/engine/userguide/eng-
image/dockerfile_best-practices/

18. BEST PRACTICES
➤ Use official base images (stand on the shoulders of giants)
➤ Be aware of unofficial (cowboy) images
➤ Use specific versions of base images
➤ Keep images small in size (remove tools that are not needed)
➤ Optimize layers (when you're done)
➤ Think about readability (use "" to continue on a new line)
➤ Update often (scheduled builds)

19. BEST PRACTICES
➤ Mount source code (possibly use ':cached')
➤ Mount local config/cache (Composer, NPM)
➤ Create separate application and build/devtools containers
➤ Run tools as yourself (uid/gid)
➤ Create helper scripts for containerized tools
➤ Log to stdout

20. BEST PRACTICES
➤ Leave out dev tools (debug tools, package managers, etc.)
➤ Leave out unnecessary files (tests, documentation, dev related
config)
➤ Do not keep state (that you can't rebuild)
➤ Consider running a container as read only
➤ Run as non root user
➤ Use health checks
➤ Spend time on setting up logging

21. RESOURCES
https://github.com/lucasvanlierop/docker-
festival-workshop
lucasvanlierop.nl/blog

22. https://leanpub.com/the-devops-2-1-toolkit

26. https://training.matthiasnoback.nl/