Docker presentation by Victor Vieux at the Paris Docker Meetup #1, hosted by Viadeo

1. Docker Paris meetup #1 – 10/02/2013
Victor Vieux, dotCloud Inc.
@vieux

2. Outline
• Intro to Docker
• Installing Docker
• Basic commands
• Demo: Simple deployment
• Questions

3. Quick survey
• How many people have heard of Docker
before this Meetup ?
• How many people have tried Docker ?
• How many people are using Docker in
production ?

4. Introduction to Docker

5. Origins of Docker
• Docker is a rewrite of similar code that
currently powers the dotCloud PaaS
• Original version written in Python (like
dotCloud PaaS), now written in Go
• It’s a young project (~6 months), but with a
huge community.

6. Docker Timeline
• January 2013 Docker started as an internal project
inside of dotCloud
• March 21, 2013 Solomon gives Docker lightning
talk a PyCon US
• March 27, 2013 Docker 0.1 released to Public
• September 4, 2013 Docker merged into Openstack
for the Havana release
• September 19, 2013 Partnership with Red Hat
around OpenShift
• September 27, 2013 Docker 0.6.3 released

7. In the first 6 months
• 6000+ Github stars
• 150+ Contributors
• 50,000+ docker index pull
• 100’s of projects built on top of Docker
– UIs (DockerUI, Shipyard, Dockland…)
– Open Source PaaS (DEIS, Flynn, Dokku…)
– Continuous Deployment (Strider…)
• 1700’s Dockerized applications on Github

8. What is Docker ?
“Docker is an open-source engine to
easily create lightweight, portable,
self-sufficient containers from any
application. The same container that
a developer builds and test on a
laptop can run at scale, in production,
on VMs, OpenStack cluster, public
clouds and more.”

9. How does Docker work ?
• LinuX Containers (LXC)
• Control Groups & Namespaces
• AUFS
• Client – Server with an HTTP API

10. LinuX Containers (LCX)
• Let’s your run a Linux system within another
Linux system
• A container is a group of processes on a
Linux box, put together is an isolated
environment
• From the inside, it looks like a VM
• From the outside, it looks like normal
processes
• “chroot on steroids”

11. Why Containers?
• Speed: Boots in seconds
• Footprint: 100-1000 containers on one
machine. Small disk requirements

12. Containers vs. VMs

13. Control Groups & Namespaces
Linux kernel feature to limit, account and
isolate resource usage, such as:
– CPU
– Memory
– Disk I/O

14. AUFS
• File system that implements union mount.
• Supports Copy On Write (COW):
# mount –t aufs –o br=/files1:/files2 none /files
# mount –t aufs –o br=/tmp=rw:/bin=ro none /files

15. Installing Docker

16. Requirements
• Linux Kernel 3.8 or above
• AUFS
• LXC
• 64-bit

17. Installations
• Ubuntu Linux
• Binaries
• Using Vagrant
More on: http://docs.docker.io/en/latest/installation

18. Installation: Ubuntu Linux
• AUFS support
$> sudo apt-get update
$> sudo apt-get intall linux-image-extra-`uname –r`
• Add Docker repository
$> sudo sh –c “curl https://get.docker.io/gpg | apt-key add -”
$> sudo sh –c “echo deb http://get.docker.io/ubuntu docker
main > /etc/apt/sources.list.d/docker.list”
• Install
$> sudo apt-get update
$> sudo apt-get install lxc-docker

19. Installation: Binaries
• Get the docker binary
$> wget –output-document=docker https://get.docker.io/builds/
Linux/x86_64/docker-latest
$> chmod +x docker
• Run the docker daemon
$> sudo ./docker –d &
• Use your own system startup script

20. Installation: Vagrant
• Clone the Docker repository
$> git clone https://github.com/dotcloud/docker.git
• Startup the vagrant image
$> vagrant up
• SSH into the image
$> vagrant ssh
• Docker client works on Mac

21. Basic
commands

22. Classic: hello world
• Get one base image (ubuntu, centos, busybox,…)
$> docker pull ubuntu
• List images on your system
$> docker images
• Print hello world
$> docker run ubuntu:12.10 echo “hello world”

23. Detached mode
• Run
in
Docker
using
the
detach
flag
(-­‐d)
$> docker run –d ubuntu sh –c “while true; do echo hello
world; sleep 1; done”
• Get
container’s
id
$> docker ps
• A:ach
to
the
container
$> docker attach <container_id>
• Stop/Start/Restart
the
container
$> docker stop <container_id>

24. Containers vs Images
• Remove a file from an image
$> docker run busybox rm /etc/passwd
• The file is still there ??
$> docker run busybox cat /etc/passwd
• Commit the newly created to an image
$> docker ps –n=2 #get the container’s id
$> docker commit <id> vieux/broken-busybox
• The file is gone
$> docker run vieux/broken-busybox cat /etc/passwd

25. Public Index & Network
• Pull an apache image from the public index
$> docker search apache
$> docker pull creack/apache2
• Run the image and check the ports
$> docker run –d creack/apache2
$> docker ps
• Expose public ports
$> docker run –d –p 8888:80 –p 4444:443 creack/apache2
$> docker ps

26. Creating your 1st app: the interactive way
• Using docker in interactive mode
$> docker run –i –t ubuntu bash
root@82c63ee50c3d:/#
root@82c63ee50c3d:/# apt-get update
[…]
root@82c63ee50c3d:/# apt-get install memcached
[…]
root@82c63ee50c3d:/# exit
• Commit the image
$> docker commit `docker ps –q –l` vieux/memcached
• Start the image
$> docker run –d –p 11211 –u daemon vieux/memcached memcached

27. Creating your 1st app: the boring way
• Multiple run / commit
$> docker run ubuntu apt-get update
$> $ID=(docker commit `docker ps –q –l`)
$> docker run $ID apt-get install memcached
$> docker commit `docker ps –q –l vieux/memcached
• Define default configuration at commit
$> docker commit –run=‘{“Entrypoint”: [“memcached”]}’ […]
• Start the image
$> docker run –d –p 11211 –u daemon vieux/memcached

28. Creating your 1st app: the scripted way
• Write a Dockerfile
# Memcached
FROM ubuntu
MAINTAINER Victor Vieux <victor@dotcloud.com>
RUN apt-get update
RUN apt-get install –y memcached
ENTRYPOINT [“memcached”]
USER daemon
EXPOSE 11211
• Buid the image
$> docker build –t=vieux/memcached .
• Start the image
$> docker run –d vieux/memcached memcached

29. Volumes and bind mounts
• Put your persistent data in a volume
$> $ID=(docker run –d –v /var/lib/mysql vieux/mysql)
• So you can re use it in another container
$> docker run –d –volumes-from=$ID vieux/mysql
• Bind mounts
$> docker run –d –v /home/vv:/home <image>
• Supports read only / read write
$> docker run –d –v host/path:container/path:rw <image>

30. Other commands
• docker cp #copy a file from container to host
• docker diff #print container changes
• docker top #display running processes inside a container
• docker rm/rmi #delete container/image
• docker wait #wait until container stop and print exit code
More on: http://docs.docker.io/en/latest/commandline/cli

31. Demo:
Simple deployment

32. Local development
• App running in prod
http://ks3100989.kimsufi.com:8080/
• Build local
$> docker build –t=gcm .
• Test local
$> docker run –p 49200:8080 gcm
http://localhost:49200
• Change some files
• Rebuild & test
$> docker build –t=gcm .
$> docker run –p 49200:8080 gcm

33. Push to prod
• Tag image in order to push it
$> docker tag gcm ks3100989.kimsufi.com:5000/gcm
• Push image to local registry
$> docker push ks3100989.kimsufi.com:5000/gcm
• On production server, download image
$> docker pull ks3100989.kimsufi.com:5000/gcm
• Restart the container
$> docker stop <container_id>
$> docker run –d –p 8080:8080 <image>

34. Questions ?

35. Thank you!
@vieux