Presentation about docker from Java User Group in Ostrava CZ (23th of November 2015). Presented by Martin Damovsky (@damovsky). Demos are available at https://github.com/damovsky/jug-ostrava-docker

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
• Discussion + Beer

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

4. Who knows Docker?

5. What is ?
Docker is an open platform for developing, shipping, and running
applications. Docker is designed to deliver your applications faster.
With Docker you can separate your applications from your
infrastructure AND treat your infrastructure like a managed application.
Docker helps you ship code faster, test faster, deploy faster, and shorten
the cycle between writing code and running code.

6. What is ?...my version
• Docker is new way of virtualization
• you virtualize only the app and not the whole OS
• + dozen of tools for container sharing, running, orchestrations, etc.
• it’s a whole platform for using containers

7. 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

9. Docker vs VM

10. How does it works?
• Use 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

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

12. Docker Container and its file system layers
Base Image (debian/ubuntu/busybox…)
Image – Added Apache
Writable Layer

13. 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

14. 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

15. Build – use Dockerfile
• Recipe for building the image
• Easy to transfer copy&paste
• versioning in git, etc..
FROM debian:wheezy
RUN apt-get update
RUN apt-get install -y python2.7
CMD python2.7 -m SimpleHTTPServer 8000

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

17. Dockerfile
• # Demo

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

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. 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

21. Docker requirements
• Technical:
• Linux kernel 3.10 +
• Knowledge:
• Linux

22. Docker on Windows / Mac OS

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

24. Docker containers are small and fast!
Demo #1 – debian
Demo #2 - tomcat

25. Docker API
•http://docs.docker.com/engine/reference/api/d
ocker_remote_api_v1.21/
•REST API
•Live demo – with using curl 

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

27. 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
• Docker Swarm – clustering the containers

28. Where can Docker be helpful?

29. …when new dev starts configuring project

30. …it works on my machine!

31. J2EE Application in Docker - demo
• https://github.com/mgreau/docker4dev-tennistour-app

33. 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/

34. RPI + Docker
• LIVE DEMO – hypriot OS httpd
• https://vimeo.com/131966874

35. DockerCon 2015 Challenge
• How many containers could really be started on PI 2?
• http://www.slideshare.net/Docker/docker-online-meetup-27-
raspberry-pi-dockercon-challenge

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

37. $ Price $
• Digital Ocean: $5 / 512 MB, 1 core, 20 GB SSD, 1TB Transfer
• Amazon: ?
• 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

38. Docker and Microsoft ???

39. Docker and Microsoft ?

40. 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
• Demo ASP.NET in Docker

41. Docker and PHP ?
• Piece of cake ;-)
• Live demo

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

43. Run GUI in Docker?
• Why not?
• https://blog.jessfraz.com/post/docker-containers-on-the-desktop/

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

46. Live Migration!
• https://blog.docker.com/2015/11/dockercon-eu-2015-container-
migration-tool/

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

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

49. 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 (!!!!)

50. Docker Public Registry and license terms 

51. 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

52. 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 ?
• $$$ = MAIN PROBLEM 

54. Many thanks to…
• Vendavo CZ for helping me with my presentation!
• And for supporting our “after party”
• Tieto CZ for JUG Ostrava organization!
• @VitekTajzich for his talk about Yowie

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