Docker is an open platform for developing, shipping, and running applications. It aims to solve the problem of maintaining different application versions across multiple platforms and servers. Docker allows applications to be packaged into standardized units called containers that contain all their dependencies so they can run reliably from one computing environment to another. Containers operate much more efficiently at runtime than virtual machines, using less memory and CPU resources. Docker images provide a lightweight template for creating containers which bundle application code and dependencies. This allows applications to be easily deployed and scaled across multiple machines.

1. Introduce to

2. Outline
What is docker?
Why docker?
Dockerfile

3. What is docker?
An open platform for developing,
shipping, and running applications

4. What it want to solve?

5. The matrix from hell
“You've got all types of servers, all types of
different languages and frameworks, and all
types of application versions to try and
maintain across those platforms”
- Ben Golub, CEO of Docker

6. The matrix from hell

7. We need a container

8. The matrix from hell

9. The matrix from hell

10. Installation

11. From ubuntu mainstream
Docker goes into Ubuntu mainstream
since 14.04
Currently, v0.9
apt-get install docker.io

12. From Official Repo
The latest version: v1.0
echo deb https://get.docker.io/ubuntu docker main > /
etc/apt/sources.list.d/docker.list
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80
--recv-keys
36A1D7869245C8950F966E92D8576A8BA88D21E9
apt-get update
apt-get install lxc-docker

13. Why Docker?

14. Fast and less overhead
Image versioning
Portable

15. Fast and less overhead

16. VM v.s. Docker

17. VM v.s. Docker
Server
Host OS

18. VM v.s. Docker
Server
Host OS
Hypervisor

19. VM v.s. Docker
Server
Host OS
VM VM
Hypervisor

20. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor

21. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.

22. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App

23. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App
Server
Host OS

24. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App
Server
Host OS
Docker Engine

25. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App
Server
Host OS
Container Container
Docker Engine

26. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App
Server
Host OS
Container Container
Docker Engine
Image1

27. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App
Server
Host OS
Container Container
Docker Engine
Image1
Image2

28. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App
Server
Host OS
Container Container
Docker Engine
Image1
App1
Image2

29. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App
Server
Host OS
Container Container
Docker Engine
Image1
App1
Image2
App2

30. VM v.s. Docker
Server
Host OS
VM VM
Guest OS
Hypervisor
Dep.
App
Server
Host OS
Container Container
Docker Engine
Image1
App1
Image2
App2
App3

31. Live Demo
IP: 10.10.100.108
Username: test
Password: 123456

32. docker pull
Download image from Docker Hub
docker pull [image]
Ex: docker pull debian

33. docker run (1)
docker run [image] [command]
-i interactive mode
-t pseudo-tty
Ex: docker -i -t run debian /bin/bash

34. Image versioning

35. Image v.s. Container
Base on LXC and AUFS
Images are read-only
Read / write on container
Files in container won’t keep
unless you commit

36. Image v.s. Container
Base on LXC and AUFS
Images are read-only
Read and write on container
Files in container won’t keep
unless you commit

37. Image v.s. Container
docker pull debian

38. Image v.s. Container
docker pull debian
docker run debian /bin/bash

39. docker commit
docker commit [Container ID] [image
name]
docker commit 1c1f5 new_image

40. Image v.s. Container
docker pull debian
docker run debian /bin/bash

41. Image v.s. Container
docker pull debian
docker commit
docker commit
docker run debian /bin/bash

42. Image v.s. Container
docker pull debian
docker commit
docker commit
docker run debian /bin/bash

43. Portable
Runs on all major Linux distributions
Boot2docker for Mac and Windows users
A ~25 MB tiny VM inside

44. Ship your container
There are three ways to ship your
container:
Docker Hub (docker push)
docker save
docker export

45. docker save / load
This packing will preserve the history of a
docker
docker save [Image Name] > [Archive
Name]
docker load < [Archive Name]

46. docker export / import
This way only keep the difference
docker export [Container ID] > [Archive
Name]
cat [Archive Name] | docker import -
[Image Name[:Tag]]

47. Separation of Data and
App

48. docker run (2)
-v [host directory]:[container directory]
Bind mount a volume
-p [host port]:[container port]
Publish a container's port to the host

49. Other useful command
docker ps
docker images
docker kill
docker rm
docker rmi
docker logs
docker inspect

50. Dockerfile

51. Syntax
FROM
RUN
ENV
ADD
VOLUME
EXPOSE
CMD

52. Example

53. docker build
docker build -t [Image Name[:Tag]]
<path to Dockerfile>
docker build -t my_image:v1 .

54. Build once, run
anywhere

55. Examples

56. My Concern
Easy to setup over a VM
Separate data and application
Reproduce my environment fast

57. Jenkins
Initialize shared volume before service
start
Use supervisor to manage multiple
services

58. One-time script

59. Can not use upstart

60. Use supervisor

61. Summarize

62. Do one thing at a time
Treat a docker container as an app

63. Ecosystem
CoreOS - Work with SystemD
Openstack - An instance type
Docker Hub (Docker Index)
Many providers
- Digital Ocean, EC2, Linode, Google
Cloud Platform

64. Gotcha
Don’t have its /sbin/init (Issue 1024)
Share kernel, can not run different Linux
Kernel at a time
Use --privileged if needed

65. Not mentioned
Link to another container
Use share volume on another container

66. Q & A