Build Docker images with Ansible: A half-blood approach. 聽完課程及演講，常有人問道：「我知道 Docker 很好，但怎樣才能用最簡單的方法，把自家的舊程式升級成 Docker 版？怎樣才能以最少心力在兩者之間交互切換？」 本次講座，我提出自己的獨門祕訣，可同時提供「無 Docker 版」及「Docker 版」兩種軟體 build/ship 模式供你選用；更可在某種範圍內，變成「極簡化的 Docker 程式」，以提供更佳的 Docker 運作品質。 Article (in Chinese): http://school.soft-arch.net/blog/247026/halfblood-docker Video: https://channel9.msdn.com/Events/Community-Open-Camp/Community-Open-Camp-2016/ComOpenCamp003 Lab materials: https://github.com/William-Yeh/build-docker-with-ansible

1.
Build Docker images with Ansible:
A half-blood approach
William Yeh
2016-08-27
http://bit.ly/halfblood-docker

2. Docker is great, but…

3. Dare you fully migrate your apps to Docker?
Q1

4. Co-exist?
Q2
The Old Way The Docker Way
Build pipeline
Configuration management
Deployment pipeline
Build pipeline
Configuration management
Deployment pipeline
inconvenient…

5. Reuse old, and apply to new…
The Old Way The Docker Way
Build pipeline
Configuration management
Deployment pipeline
Build pipeline
Configuration management
Deployment pipeline
… with minimal effort
… smooth learning curve
… ease of maintenance
… graceful degradation
… be a good citizen
My proposal:

6. Should fits into Docker model.
Should be of good quality.
… be a good citizen
in the Docker world

7. Nginx wrk Boom json-server
built via
package
manager
C compiler Go compiler
Node.js
runtime
http://bit.ly/halfblood-docker

8. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.

9. 1. Use CM to build image.
Base image:
williamyeh/ansible
playbook

10. 1. Use CM to build image.
2. Adapt for Dockerized app.
Major
1. Process execution model.
2. Storage model (embrace immutable infra, please).
3. Network model.
Ref. "Dockerized app "
http://william-yeh.github.io/docker-workshop/slides/dockerize.html
Minor
4. Log handling.
5. Init/upstart/systemd handling.
6. Wrapper scripts as new entrypoint, if necessary.

11. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
Base image: williamyeh/ansible:mini-debian8
Minimal configuration:
the Ansible body will be removed when mission completed.

12. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.
Base image: williamyeh/ansible:mini-alpine3
Ref:
1. " Docker image "
http://william-yeh.github.io/docker-mini/
2. " Alpine Linux"
http://school.soft-arch.net/courses/docker-part2/lectures/885446
use Alpine Linux in Ansible playbooks.
playbook

13. nginx

14. Background info
• Written in C
• Can be installed via OS-level package manager
(apt, yum, apk, …)
nginx
Debian
Ubuntu
CentOS
RHEL
Fedora
Alpine

15. 1. Use CM to build image.
nginx
playbook

16. 1. Use CM to build image.
nginx

17. 1. Use CM to build image.
nginx

18. ├─<missing> Virtual Size: 125.1 MB
│ └─<missing> Virtual Size: 125.1 MB Tags: debian:jessie
│ │
│ └─ad7fe256ceb4 Virtual Size: 200.9 MB Tags: williamyeh/ansible:debian8-onbuild
│ │
│ └─482d24d32738 Virtual Size: 210.5 MB
│ │
│ └─5b8665aa9bbc Virtual Size: 241.2 MB Tags: nginx-1:latest
1. Use CM to build image.
nginx

19. nginx
1. Use CM to build image.
2. Adapt for Dockerized app.

20. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
nginx
williamyeh/ansible:mini-debian8
williamyeh/ansible:debian8-onbuild
Base image:

21. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
nginx
├─<missing> Virtual Size: 125.1 MB
│ └─<missing> Virtual Size: 125.1 MB Tags: debian:jessie
│ │
│ ├─cb9b094476db Virtual Size: 125.1 MB Tags: williamyeh/ansible:mini-debian8
│ │ └─68b7807607da Virtual Size: 135.9 MB Tags: nginx-3:latest
│ │
│ └─ad7fe256ceb4 Virtual Size: 200.9 MB Tags: williamyeh/ansible:debian8-onbuild
│ └─482d24d32738 Virtual Size: 210.5 MB
│ └─5b8665aa9bbc Virtual Size: 241.2 MB Tags: nginx-1:latest

22. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.
nginx
williamyeh/ansible:mini-alpine3
williamyeh/ansible:mini-debian8
Base image:

23. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.
nginx

24. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.
nginx
├─<missing> Virtual Size: 4.8 MB Tags: alpine:3.4
│ │
│ └─c887641f2cdb Virtual Size: 4.8 MB Tags: williamyeh/ansible:mini-alpine3
│ └─b57f615a2cd9 Virtual Size: 6.8 MB Tags: nginx-4:latest
│
├─<missing> Virtual Size: 125.1 MB
│ └─<missing> Virtual Size: 125.1 MB Tags: debian:jessie
│ │
│ ├─cb9b094476db Virtual Size: 125.1 MB Tags: williamyeh/ansible:mini-debian8
│ │ └─68b7807607da Virtual Size: 135.9 MB Tags: nginx-3:latest
│ │
│ └─ad7fe256ceb4 Virtual Size: 200.9 MB Tags: williamyeh/ansible:debian8-onbuild
│ └─482d24d32738 Virtual Size: 210.5 MB
│ └─5b8665aa9bbc Virtual Size: 241.2 MB Tags: nginx-1:latest

25. Should be of good quality.
… be a good citizen in the Docker world

26. wrk

27. Background info
• Written in C
• Need to be compiled with gcc (& make).
wrk
https://github.com/wg/wrk
Modern HTTP benchmarking tool

28. 1. Use CM to build image.
wrk
playbook

29. 1. Use CM to build image.
wrk

30. 1. Use CM to build image.
wrk

31. ├─<missing> Virtual Size: 125.1 MB
│ └─<missing> Virtual Size: 125.1 MB Tags: debian:jessie
│ │
│ └─ad7fe256ceb4 Virtual Size: 200.9 MB Tags: williamyeh/ansible:debian8-onbuild
│ │
│ └─482d24d32738 Virtual Size: 210.5 MB
│ └─e755d268bd41 Virtual Size: 341.0 MB Tags: wrk-1:latest
1. Use CM to build image.
wrk

32. wrk
1. Use CM to build image.
2. Adapt for Dockerized app.
N/A

33. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
wrk
williamyeh/ansible:mini-debian8
williamyeh/ansible:debian8-onbuild
Base image:

34. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
wrk
├─<missing> Virtual Size: 125.1 MB
│ └─<missing> Virtual Size: 125.1 MB Tags: debian:jessie
│ │
│ ├─cb9b094476db Virtual Size: 125.1 MB Tags: williamyeh/ansible:mini-debian8
│ │ └─980aa6023fda Virtual Size: 164.3 MB Tags: wrk-3:latest
│ │
│ └─ad7fe256ceb4 Virtual Size: 200.9 MB Tags: williamyeh/ansible:debian8-onbuild
│ └─482d24d32738 Virtual Size: 210.5 MB
│ └─e755d268bd41 Virtual Size: 341.0 MB Tags: wrk-1:latest

35. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.
wrk
williamyeh/ansible:mini-alpine3
williamyeh/ansible:mini-debian8
Base image:

36. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.
wrk

37. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.
wrk
├─<missing> Virtual Size: 4.8 MB Tags: alpine:3.4
│ │
│ └─c887641f2cdb Virtual Size: 4.8 MB Tags: williamyeh/ansible:mini-alpine3
│ └─531aed862a98 Virtual Size: 9.1 MB Tags: wrk-4:latest
│
├─<missing> Virtual Size: 125.1 MB
│ └─<missing> Virtual Size: 125.1 MB Tags: debian:jessie
│ │
│ ├─cb9b094476db Virtual Size: 125.1 MB Tags: williamyeh/ansible:mini-debian8
│ │ └─980aa6023fda Virtual Size: 164.3 MB Tags: wrk-3:latest
│ │
│ └─ad7fe256ceb4 Virtual Size: 200.9 MB Tags: williamyeh/ansible:debian8-onbuild
│ └─482d24d32738 Virtual Size: 210.5 MB
│ └─e755d268bd41 Virtual Size: 341.0 MB Tags: wrk-1:latest

38. Should be of good quality.
… be a good citizen in the Docker world

39. Should be of good quality.
… be a good citizen in the Docker world

40. Boom
json-server

41. Background info
• Written in Go
• Need to be compiled.
• Written in Node.js
• Need to install Node.js runtime.
Boom
json-server

42. ├─<missing> Virtual Size: 4.8 MB Tags: alpine:3.4
│ │
│ └─c887641f2cdb Virtual Size: 4.8 MB Tags: williamyeh/ansible:mini-alpine3
│ │
│ ├─fc72e24cae3c Virtual Size: 14.5 MB Tags: williamyeh/boom:latest
│ │
│ └─bfd0226b6d74 Virtual Size: 27.5 MB Tags: williamyeh/json-server:latest
https://github.com/William-Yeh/docker-boom
https://github.com/William-Yeh/docker-json-server

43. Conclusion

44. … whether you’d like to dive into Docker
(fully or partially)
“Infrastructure as Code” mindset

45. … having alternatives is good
Consider Plan B

46. 1. Use CM to build image.
2. Adapt for Dockerized app.
3. Slim down the image.
4. Pursue for minimal image.

47. Nginx wrk Boom json-server
built via
package
manager
C compiler Go compiler
Node.js
runtime
(near-) minimal
size (MiB)
6.8 9.1 14.51 27.48

48. http://bit.ly/halfblood-docker