Run Java applications with Docker on

the Raspberry Pi and other platforms

Johan Janssen, Info Support

Content

Internet of Things

Docker and Java on a Raspberry Pi

Jenkins

Questions

Internet of Things

Potential market

Huge and still growing

Not stable yet, lots of innovation

Cool new technologies

Suitable for Java!

Weather station

Drone

Wave Glider

Wearables

Robots

Raspberry Pi

Raspberry Pi

Developments outside the IoT

Continuous Delivery Virtual machines Provisioning (Chef, Puppet, Vagrant …) Version control / infrastructure as code Isolation

Updating and synchronizing environments

IoT limitations

What to deliver?

Docker

Transportation issue

Transportation solution

Software issue

Software solution

Docker compatibility

Why Docker To enable continuous delivery Quickly provision environments Easy to roll forward Security

For instance to run ‘untrusted’ applications like a Dropbox client

Alternative for virtual machines On top of virtual machines

Docker vs Virtual Machines Disk space efficiency Memory efficiency Speed Compatibility (run anywhere) Isolation Versioning Internet of Things (Raspberry Pi etc.)

Docker vs provisioning tools

Simple general commands No Domain Specific Language (DSL) Configuration with operating system

commands

Docker activity Since March 2013 More than 460 570 contributors Downloaded 2.75 13 million times More than 14000 30000 Dockerized apps More than 90 user groups, DockerCon

(Europe) Support from Google, VMWare,

RackSpace, Red Hat, IBM, Microsoft etcetera

Docker on CIO TODAY

Docker ecosystem

My first Docker container

Docker on Ubuntu 14.04

apt-get install docker.io

docker.io run -i -t ubuntu:saucy /bin/bash

My first Pi Docker container

Docker on the Raspberry Pi

docker run -i –tresin/rpi-raspbian

/bin/bash

Docker technology

Raspberry installation Download Arch Linux http://downloads.raspberrypi.org/arch_latest unzip ArchLinuxARM-2014.06-rpi.img.zip Find SD card: sudo fdisk -l sudo dd bs=1M if=ArchLinuxARM-2014.06-rpi.img of=/dev/sdX Change partitions (optional) Put the SD card in the Raspberry Pi and boot username and password are both ‘root’

Raspberry installation Update repositoriespacman –Syy

Optional update al packages: pacman -Syu

Install Dockerpacman -S docker

Raspberry installation Start Docker servicesystemctl start docker

Auto start Docker service on bootsystemctl enable docker

Reboot

Configure static IP address cp /etc/netctl/examples/ethernet-static /etc/netctl/static Edit /etc/netctl/static

Description='A basic static ethernet connection'Interface=eth0Connection=ethernetAutoWired=yesIP=staticAddress=('192.168.1.3/24')Gateway='192.168.1.1'DNS=('192.168.1.1')

Static IP address Enable static ip

netctl enable static

Disable static ip mv /etc/netctl/static /etc/netctl/examples/

Tomcat DockerfileFROM resin/rpi-raspbianRUN apt-get update

RUN apt-get install -y openjdk-7-jre-headless wgetRUN wget -O /tmp/tomcat8.tar.gz http://archive.apache.org/dist/tomcat/tomcat-8/v8.0.9/bin/apache-tomcat-8.0.9.tar.gzRUN (cd /opt && tar zxf /tmp/tomcat8.tar.gz)RUN (mv /opt/apache-tomcat* /opt/tomcat)ENV JAVA_HOME /usr/lib/jvm/java-1.7.0-openjdk-armhf

RUN rm -rf /opt/tomcat/webapps/docs /opt/tomcat/webapps/examples /opt/tomcat/webapps/host-manager /opt/tomcat/webapps/manager

EXPOSE 8080CMD ["/opt/tomcat/bin/catalina.sh", "run"]

Tomcat Dockerfile explainedFROM resin/rpi-raspbian

RUN apt-get install -y openjdk-7-jre-headless wget

ENV JAVA_HOME /usr/lib/jvm/java-1.7.0-openjdk-armhf

EXPOSE 8080CMD ["/opt/tomcat/bin/catalina.sh", "run"]

TomcatExtra DockerfileFROM tomcat

ADD DockerPiExample.war /opt/tomcat/webapps/

Directory structure Main directory

BuildAndRunScript.sh Tomcat

Dockerfile TomcatExtra

Dockerfile DockerPiExample.war

Build Create the Dockerfiles Build the containers

cd Tomcat (optional)docker build -t tomcat . (optional)cd .. (optional)cd TomcatExtradocker build -t tomcatextra .

Run Start the container

docker run -p 8080:8080 -d tomcatextra

Hyper Text Coffee Pot Control Protocol

April Fools prank

It might become real

Hyper Text Coffee Pot Control Protocol

Controlling containers

Start / stop / restartdocker [start/stop/restart] containerid

Follow SystemOut and SystemErrdocker logs -f containerid

Controlling containers Show (running) containers

docker ps –a

Show processes running in containerdocker diff containerid

Show changes in the containerdocker top containerid

Controlling containers Stop all containers

docker.io stop $(docker.io ps -a -q) Remove all containers

docker.io rm $(docker.io ps -a -q) Remove all images

docker.io rmi $(docker.io images -q)

Demo

Docker overview

One ring to rule them all

Docker registry

Creating the Docker registrydocker run -p 5000:5000 registry

Docker client 1 (push) Change container (using touch for instance) Commit

docker.io commit 064f192.168.56.31:5000/test-version-0.2

New containerid -> ff7e Push

docker.io push 192.168.56.31:5000/test-version-0.2

Docker client 2 (pull) Pull

docker.io pull 192.168.56.31:5000/test-version-0.2

Rundocker.io run -i -t ff7e /bin/bash

Updating containers

Pull update only on Docker client 2

docker images -tree└─153bf43b408a 194.2 MB test-version-0.1:latest

docker pull 192.168.56.31:5000/test-version-0.2 ff7e110ebadd: Download complete153bf43b408a: Download complete

docker images -tree└─153bf43b408a 194.2 MB test-version-0.1:latest └─ff7e110ebadd 194.2 MB test-version-0.2:latest

Use registry instead exports

Commands are easier

Faster and easier migration

Use registry instead of multiple builds

Requires less extra resources

Containers are the same, for instance when using apt-get update

Not the latest security patches

Docker vs Virtual Machines

We need lots of Docker containers

GeneralBase

AppServerBase

Environment D

Environment T

Environment A

Environment P

Jenkins

JenkinsDataContainer

Sonar Gitblit Nexus

Diskspace# docker.io images --tree└─ 179.9 MB Tags: ubuntu:saucy └─253.6 MB └─741.8 MB Tags: GeneralBase:latest └─763.6 MB Tags: AppServerBase:latest

├─763.6 MB Tags: EnvironmentP:latest └─865.6 MB Tags: Nexus:latest └─808.3 MB Tags: Gitblit:latest └─901.5 MB Tags: Sonar:latest └─805.4 MB Tags: Jenkins:latest

Execution time on laptop

real 4m11.729suser 0m3.329s sys 0m10.054s

Jenkins

Why Jenkins Simple to use Really popular

Used in many organizations Regular updates Big community creating plugins etc.

Most developers already use it

Jenkins demo

Tips

Deploy the first container when the hardware is nearby this saves network traffic Use a (private) Docker registry Keep environmental settings separate

Start playing with Docker!

Summary

Big potential market for Docker and Java

Easy to use

Highly flexible and customizable

Isolation

Isolation

Isolation

Isolation

Questions

johan.janssen@infosupport.com