Dockerize the world!

Martin Damovský

My plan for today

• Introduction to Docker

• Some demos

• Docker in Cloud

• IoT and Docker

• News from DockerCon 2015 in SF and Barcelona

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

Who knows Docker?

Who uses Docker in production?

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

What is ?

• Docker is a whole platform for using containers

• Includes tools for:

• container sharing

• orchestrations, clustering, etc.

What is ?

• Docker is for Linux only

• But…Microsoft works on Docker for Windows

• Apple (MacOS) = no native support planned

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

Docker vs VM

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

Docker mottoBuild – build container with your app

Ship - use docker registry to distribute your app

Run - wherever docker runs, your app will run as well

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 updateRUN apt-get install -y python2.7

CMD python2.7 -m SimpleHTTPServer 8000

Docker “flow”1. create docker file2. build dockerfile

$ docker build -t myTagName .3. run container

$ docker run -d myTagName

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

Dockerfile commands• FROM

• RUN

• CMD

• ADD

• USER

• ENV

• etc….see at http://docs.docker.com/reference/builder/

It’s all about the money!LAYERS!

Dockerfile vs layersFROM debian:wheezy

RUN apt-get updateRUN 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

Dockerfile, build, run• # Demo 02

• Python http server + Connect to container

Docker Image

Base Image (debian/ubuntu/…)

Docker Image

Base Image (debian/ubuntu/busybox…)

Image – Added Apache

Docker Image Container

Base Image (debian/ubuntu/busybox…)

Image – Added Apache

Writable Layer

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

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

Docker requirements• Technical:• Linux kernel 3.10 +

• Knowledge:• Linux, bash scripting, etc

Docker on Windows / Mac OS

Linux

Docker daemon

Container

Container

Container

Docker client

Mac OS / Windows

VM with Linux

Docker daemon

Container

Container

Container

Docker client

Docker API•http://docs.docker.com/engine/reference/api/docker_remote_api_v1.21/•REST API for everything•Container management• Image management•Docker configuration, etc…

Docker itself is….like a java

Without tools and frameworks it’s useless

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

Where can Docker be helpful?

…when new dev starts configuring project

…it works on my machine!

J2EE Application in Docker - demo

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

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/

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

y-pi-dockercon-challenge

Docker in Cloud• Digital Ocean• UI Tutum.co – worth to try!

• Amazon• Microsoft Azure• Google Cloud

$ 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

Docker and Microsoft ???

Docker and Microsoft ?

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…

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

Docker orchestration• Docker Swarm• Kubernetes• Apache Mesos

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

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

containers.

Live Migration!• Migration of running container from one host to second• https

://blog.docker.com/2015/11/dockercon-eu-2015-container-migration-tool/

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

Troubles you may face….

….with Docker

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 (!!!!)

Docker Public Registry and license terms

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

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 {}

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 ?

Links:• My demos• https://github.com/damovsky/jug-ostrava-docker

• Yowie – Open source project by @VitekTajzich• https://github.com/vendavo/yowie