Using docker to develop NAS applications

1. Using Docker to develop
NAS application
Terry Chen

2. About me
● Backend engineer : Java, Python, Linux
● QNAP Container Station/Linux Station
https://www.linkedin.com/in/seterrychen
https://github.com/seterrychen
https://twitter.com/seterrychen

3. Outline
● Introduce basic knowledge of Docker
● Using Docker to deploy NAS applications

4. What is container?
From : Macmillan Dictionary

5. What is container?
From : Macmillan Dictionary From : http://www.containerhireaust.com.au/containers/20-foot-general-purpose/

6. Before container
From：https://en.wikipedia.org/wiki/Stevedore

7. With container
From : http://pointful.github.io/docker-intro/#/6

8. Other key property of container
Isolation

9. Deploy software
From : https://goo.gl/YIKVMJ
http://www.hive-io.com/virtual-server-infrastructure/
Development Environment Production Environment

10. Application stack
OS Kernel
System libraries
Language runtime
Application code
Configuration

11. Container concept in software engineering
From : http://www.vccoaching.com/smarter-thinking/
http://pclosmag.com/html/Issues/201304/page08.html
OS Kernel
System libraries
Language runtime
Application code
Configuration

12. Virtual machine
OS Kernel
System libraries
Language runtime
Application code
Configuration

13. Linux Container (LXC)
OS Kernel
System
libraries
Language
runtime
Application
code
Configuration
System
libraries
Language
runtime
Application
code
Configuration
System
libraries
Language
runtime
Application
code
Configuration
System libraries
Language runtime
Application code
Configuration

14. VM vs container

15. Basic isolation of Linux
● chroot : A chroot on Unix operating systems is an operation that changes the
apparent root directory for the current running process and its children.
From : http://freedompenguin.com/articles/how-to/learning-the-linux-file-system/

16. DEMO

17. Isolation of LXC
● Linux Kernel feature :
○ Namespaces
■ Mount namespaces
■ UTS namespaces
■ IPC namespaces
■ PID namespaces
■ Network namespaces
■ User namespaces

18. Tools of LXC
● lxc-create : download base rootfs and create a container
● lxc-start, lxc-stop … : control the container
● lxc-attach : start a process inside a running container
● lxc-ls : list all containers status

19. DEMO

20. Pain point when using LXC (in my case)
● Install your application by script
● Deploy containers by manual
● No version control system/repositories to store containers you already install
application
From : http://icons.iconarchive.com/icons/babasse/imod/72/Tar-icon.png
Host 1 Host 2
container-v1.0 container-v2.0 container-v3.0 container-v1.0 container-v1.1

21. 教練，我只想運作我的程式！！

22. What is Docker ?
Docker is an open-source engine which automates the deployment of applications
as highly portable, self-sufficient containers.
(From : https://github.com/docker/docker/wiki/Docker-0.3.0-release-note,-May-6-2013)

23. Docker and Linux
From : https://en.wikipedia.org/wiki/Docker_(software)

24. Docker power
From : https://yq.aliyun.com/articles/32071
Dockerfile

25. Dockerfile
FROM alpine:3.3
RUN apk add --no-cache nginx

26. Docker build my-nginx:0.1 image
FROM alpine:3.3
RUN apk add --no-cache nginx

27. Docker build my-nginx:0.1 image
FROM alpine:3.3
RUN apk add --no-cache nginx
From : http://thepapist.org/ask-a-question/

28. Layers of My-nginx image (Docker version 1.9)
0dcd4549ae28 4.797 MB
ff2b369bf5c3 1.454 MB
Image : my-nginx:0.1
FROM alpine:3.3
RUN apk add --no-cache nginx

29. Docker image / container
0dcd4549ae28 4.797 MB
ff2b369bf5c3 1.454 MB
Image : my-nginx:0.1
Container
mount

30. AUFS – Another Union File System
From : https://docs.docker.com/engine/userguide/storagedriver/aufs-driver/

31. DEMO

32. Process inside container
my-nginx container
nginx: master process
nginx: worker process
PID 1
host
nginx: master process
nginx: worker process
PID 5566

33. Stop container
my-nginx container
nginx: master process
nginx: worker process
Send SIGTERM

34. Install dockerized application by qpkg
● For example : Redmine ( docker-qdk2 )
├── icons
├── package_routines
├── qpkg.cfg
├── shared
│ ├── docker-compose.yml
│ ├── redmine.conf
│ └── redmine.sh
└── x86_64

35. docker-compose
postgresql:
image: sameersbn/postgresql:9.4-11
environment:
- DB_USER=redmine
- DB_PASS=password
- DB_NAME=redmine_production
redmine:
image: sameersbn/redmine:3.2.0-1
links:
- postgresql:postgresql
environment:
- REDMINE_PORT=10083
- REDMINE_RELATIVE_URL_ROOT=/redmine
ports:
- "127.0.0.1:10083:80"

36. Redmine.conf
ProxyRequests off
ProxyPass /redmine/ http://127.0.0.1:10083/redmine/
ProxyPassReverse /redmine/ http://127.0.0.1:10083/redmine/

37. Package_routines
pkg_post_install() {
…..
DEPEND_ON=container-station
/sbin/setcfg $QPKG_NAME depend_on "${DEPEND_ON}" -f /etc/config/qpkg.conf
/sbin/log_tool -t0 -uSystem -p127.0.0.1 -mlocalhost -a "[$QPKG_NAME] Start installation"
$CONTAINER_STATION/bin/qbus post com.qnap.dqpkg/qpkg '{"qpkg": "'$QPKG_NAME'",
"action": "install"}'
}

38. Container Station API
● Version V1.6.1600

39. DEMO

40. Common questions
Q: Can skip the initialization of Container Station ?
A: Using system-docker

41. Common questions
Q: Why is a container suddenly closed after executing docker run ?
A: The PID 1 process inside container is closed. Please using bash replace the
default command to debug.

42. Common questions
Q: How to backup data of a container
A: Using docker run -v /host_path/backup:/container_path/data

43. Common questions
Q: At container, how to get information of NAS
A: Using docker -v /host/your_socket:/container/run.
Example : -v /etc/qbus:/etc/qbus -v /var/run/qbus.sock:/var/run/qbus.sock -v
/share/CACHEDEV2_DATA/.qpkg/container-station/usr/bin/.libs/qbus:/bin/qbus

44. Common questions
Q: How to learn Docker ?
A: Docker Docs is your friend!

45. From : http://9gag.com/gag/anYZ9Eo/my-code-works-but-i-don-t-know-why

46. From: http://blog.octanner.com/wp-content/uploads/2013/12/thankyou.jpg