This document provides an introduction and overview of Docker delivered in a presentation format. It includes: 1. An agenda that covers Docker introduction, demos, Docker in the cloud, IoT and Docker, and news from DockerCon conferences. 2. Background on the presenter and a poll asking who knows and uses Docker in production. 3. Explanations of what Docker is, how it works using Linux kernel features, and its motto of Build, Ship, Run. 4. Mention of links to the presenter's Docker demos and an open source project called Yowie.

1. Dockerize the world!
Martin Damovský

2. My plan for today
• Introduction to Docker
• Some demos
• Docker in Cloud
• IoT and Docker
• News from DockerCon 2015 in SF and Barcelona

3. Who am I?
• Software engineer (java, DBs, continuous integrations, docker, etc.)
• Grew up in small city near Ostrava
• Tieto Czech s.r.o. Ostrava, Gemalto in Prague
• Now in Vendavo CZ in Prague
• Twitter @damovsky

4. Who knows Docker?

5. Who uses Docker in production?

6. What is ?
• Docker is virtualization technology
• With docker you can:
• virtualize only the app and not the whole OS
• Isolate each app
• Restrict CPU / memory / for each app
• Easily distribute your app
• Automate your development / test / production environment

7. What is ?
• Docker is a whole platform for using containers
• Includes tools for:
• container sharing
• orchestrations, clustering, etc.

8. What is ?
• Docker is for Linux only
• But…Microsoft works on Docker for Windows
• Apple (MacOS) = no native support planned 

9. Docker project
• Docker inc. is a sponsor of “Docker” open source project
• https://github.com/docker/docker
• Written in Go
• Main contributors: Docker team, RedHat, IBM, Google, Cisco…
• Initial release: 13 March 2013
• Operation system: Linux
• www.docker.com

11. Docker vs VM

12. How does it works?
• Use Linux kernel support for isolation (CPU, memory, I/O, network….)
• Cgroups – linux kernel feature to limit resource usages
• Namespaces – linux kernel feature to isolate services from each other
• Earlier LXC – https://linuxcontainers.org
• Now – runC (Libcontainer) https://github.com/opencontainers/runc

13. Docker motto
Build – build container with your app
Ship - use docker registry to distribute your app
Run - wherever docker runs, your app will run as
well

14. DockerFile = cookbook for docker image
• Recipe for building the image
• Easy to transfer copy&paste
• Easy for versioning in Git, etc..
FROM debian:wheezy
RUN apt-get update
RUN apt-get install -y python2.7
CMD python2.7 -m SimpleHTTPServer 8000

15. Docker “flow”
1. create docker file
2. build dockerfile
$ docker build -t myTagName .
3. run container
$ docker run -d myTagName

16. Dockerfile
• # Demo 01
• https://asciinema.org/a/7m72btfpczbshfkxh26smwgqv

17. Dockerfile commands
• FROM
• RUN
• CMD
• ADD
• USER
• ENV
• etc….see at http://docs.docker.com/reference/builder/

18. It’s all about the money!
LAYERS!

19. Dockerfile vs layers
FROM debian:wheezy
RUN apt-get update
RUN apt-get install -y python2.7
CMD python2.7 -m SimpleHTTPServer 8000
└─61f… Virtual Size: 85.1 MB Tags: debian:wheezy
└─5b8.. Virtual Size: 93.4 MB
└─604.. Virtual Size: 123.5 MB
└─43e.. Virtual Size: 123.5 MB Tags: python:latest

20. Dockerfile, build, run
• # Demo 02
• Python http server + Connect to container

21. Docker Image
Base Image (debian/ubuntu/…)

22. Docker Image
Base Image (debian/ubuntu/busybox…)
Image – Added Apache

23. Docker Image Container
Base Image (debian/ubuntu/busybox…)
Image – Added Apache
Writable Layer

24. Docker Container and its file system layers
Base Image (debian/ubuntu/busybox…)
Image – Added
Apache
Writable Layer
Image – Added
MySQL
Writable Layer
Container #1 Container #2

25. Docker registry
• https://registry.hub.docker.com/
• Official repo (trusted builds)
• WordPress, MySQL, NgInx, Node, CentOS, Ubuntu, Postgress, mongo, rails, ruby,
java, python, golang, jenkins, php, tomcat, maven, httpd, …
• Public repo with thousands of images
• Integration with GitHub
• You push the Dockerfile to github
• Docker Registry builds the docker image for you

26. Docker requirements
• Technical:
• Linux kernel 3.10 +
• Knowledge:
• Linux, bash scripting, etc

27. Docker on Windows / Mac OS

28. Linux
Docker daemon
Container
Container
Container
Docker client
Mac OS / Windows
VM with Linux
Docker daemon
Container
Container
Container
Docker client

29. Docker API
•http://docs.docker.com/engine/reference/api/d
ocker_remote_api_v1.21/
•REST API for everything
•Container management
•Image management
•Docker configuration, etc…

30. Docker itself is….like a java
Without tools and frameworks
it’s useless

31. Docker Toolbox
• Docker engine
• Kinematic – GUI, runs on MacOS + Windows
• Docker Machine – automates Docker environment preparation
• Docker Compose – define multi-container application in one file
• Demo 03
• Docker Swarm – clustering the containers

32. Where can Docker be helpful?

33. …when new dev starts configuring project

34. …it works on my machine!

35. J2EE Application in Docker - demo

36. J2EE Application in Docker - demo
• https://github.com/mgreau/docker4dev-tennistour-app
• https://asciinema.org/a/2d6erl2tlu1j0b3rfvxwabnkv
• #Demo 04

38. Docker and IoT (Raspberry Pi)
• ARM vs x86/64 architecture
• Docker to plan official support ARM
• HypriotOS – linux distro for Raspberry
• Hypriot OS based images:
• https://hub.docker.com/u/hypriot/

39. RPI 2 + Docker = 2499 containers
• LIVE DEMO – hypriot OS httpd
• https://vimeo.com/131966874
• http://www.slideshare.net/Docker/docker-online-meetup-27-
raspberry-pi-dockercon-challenge

40. Docker in Cloud
• Digital Ocean
• UI Tutum.co – worth to try!
• Amazon
• Microsoft Azure
• Google Cloud

41. $ Price $
• Digital Ocean: $5 / 512 MB, 1 core, 20 GB SSD, 1TB Transfer
• Amazon: it depends on many factors
• Microsoft Azure
• Google Cloud: free up to 5 nodes, 6+ nodes $0.15 HR/Cluster
• Alternative: VSPFree.cz 4GB RAM, 8 cores, 900 Kč /3 Months

42. Docker and Microsoft ???

43. Docker and Microsoft ?

44. Docker and Microsoft ?
• Microsoft contributes to docker
• see pull request https://github.com/docker/docker/pull/9113
• Microsoft Azure supports docker
• Native Docker on Windows Server is coming…

45. Docker and PHP ?
• Piece of cake ;-)
• #Demo 05

46. Docker orchestration
• Docker Swarm
• Kubernetes
• Apache Mesos

47. Run GUI in Docker?
• https://blog.jessfraz.com/post/docker-containers-on-the-desktop/
• #Demo 06

49. Dockercraft
• A simple Minecraft Docker client, to visualize and manage Docker
containers.

50. Live Migration!
• Migration of running container from one host to second
• https://blog.docker.com/2015/11/dockercon-eu-2015-container-
migration-tool/

51. What’s in Docker roadmap?
• Official ARM support
• Docker on Windows Server
• Docker on IBM systems, Solaris

52. Troubles you may face….
….with Docker

53. Docker Registry - Image Repository
• Public – no way for 99,9% apps
• Private
• Limitation – money & your internet connection speed
• Local repo - can require some management
• Authentication (users/passwords/roles, etc…)
• cleaning olds images
• disk space
• backup (!!!!)

54. Docker Public Registry and license terms 

55. Unrealistic tutorials and demos
• Demos = “wow effect”
• Typical problem for production use – database in container
• Database container can really be big! (>10 GB or more)
• Data should be outside of container and backuped
• Virtualization decreases the performance

56. Docker containers and images
• Image is too big -> Squash layers
• Container has been stopped, but it blocks the port...
• Stopped != removed
• docker ps -a -q | xargs -n 1 -I {} docker rm {}

57. Run Docker on dedicated machine only
• You should use the latest Linux Kernel
• Some bug fixes may require you to update Linux Kernel
• Who can update Linux kernel in production?
• Which file system to use? BTRFS / AUFS / ?
• Which OS ?
• Core OS
• RancherOS
• Well known like a CentOS, Red Hat, Ubuntu ?

58. Links:
• My demos
• https://github.com/damovsky/jug-ostrava-docker
• Yowie – Open source project by @VitekTajzich
• https://github.com/vendavo/yowie