On Thursday the 28th of January 2016, Anthony Dahanne gave a talk on how to leverage Docker to package Java applications. After a quick introduction to Docker principles, Anthony showed some demos (available on github) on how to create Docker images for simple and not so simple Java webapps. Then, he went on with CI/CD examples, and finished with a quick intro to the Docker Java API. http://blog.dahanne.net/2016/01/31/docker-and-java-notes-from-the-montreal-jug-presentation/

1. DOCKER AND JAVA
ANTHONY DAHANNE, MONTRÉAL JUG, JANUARY 28TH 2016
@anthonydahanne

2. Anthony Dahanne, Software Engineer @
Terracotta, a Software AG company
Working on the Terracotta Management Console,
and its integration in Terracotta products
And strong Docker supporter :-P , trying to
containerize as much as I can !
LET ME INTRODUCE MYSELF
We’re hiring Software Engineers ! Contact me !

3. AGENDA
• Docker fundamentals : quick recap
• Java applications in containers
• Hello world from a Java container
• SpringBoot app in a container (+ Maven + IntelliJ IDEA integrations)
• Java Web Applications (war) Docker pipelines
• Docker cloud based CI/CD
• CI/CD using on premises familiar tools (Jenkins, Nexus)
• Extras
• Jenkins container-based slaves
• Interacting with Docker from Java with Docker Java

4. VMS VS CONTAINERS
IT’S ALL ABOUT THE (LINUX?) KERNEL !
picture from http://www.enterprisetech.com/2014/08/18/ibm-techies-pit-docker-kvm-bare-metal/

5. DOCKER CONTAINERS / IMAGES : A PILE OF LAYERS
A DOCKER IMAGE IS A DIFF ON TOP OF ITS PARENT
picture from : https://docs.docker.com/v1.6/terms/layer/

6. Host OS
Docker daemon
Images Containers
Docker CLI
> docker run ubuntu bash
> docker ps
> docker images
> etc.
Docker Compose
> docker-compose build
> docker-compose up
> docker-compose kill
> etc. Volumes
Kinematic
REST API
tcp (tls) / Unix socket
Host OS
Docker daemon
Ima
ges
Conta
iners
Volum
es

7. DOCKER VOCABULARY VS JAVA VOCABULARY
• Repository : houses grouped artifacts
• Artifact : org.ehcache:ehcache:3.0.0.m4 (+type : jar/sources/etc.)
Group id VersionArtifact id

8. DOCKER VOCABULARY VS JAVA VOCABULARY
• Registry : hosts repositories
• Repositories : house collections of tagged images
• Image : localhost:5000/anthony/mycoolimage:v2
DockerHub / quay.io / Registry V2
Registry location Repository name Tag

9. Registry @ SoftwareAG
anthony/tmc
Registry
ubuntu anthonydahanne/terracotta
anthonydahanne/petclinic
latest 12.04 latest
4.3.1-
oss latest 5.0
Host OS
Docker CLI
Docker daemon
Images
Host OS
Docker daemon
Images
Docker CLI
REST API
tcp (tls) / Unix socket

10. DEMO TIME !
• Hello world from a Java container
• SpringBoot app in a container (+ Maven + IntelliJ IDEA integrations)

11. DOCKER CLOUD BASED CI/CD
PUSH THAT CODE AROUND !
EC2 Azure GCE
TutumGithub DockerHub
Commit & Push
Trigger Automated Build Trigger Redeploy / Scale
Create & Start Container

12. DEMO TIME !
• Petclinic cloud based CI/CD
• Petclinic built (war + image) by DockerHub
• Deployed by Tutum

13. ON PREMISES CI/CD
RE USING EXISTING INFRA !
Git Repo
Jenkins
Commit & Push
Trigger mvn job
Create & Start Container
Docker
daemons
Regular
Slaves
Registry
Image build Push image to registry
Docker
daemon

14. DEMO TIME !
• Petclinic built (war and then image) by Jenkins
• Pushed to Nexus 3 by Jenkins
• Deployed to a machine running Docker by Jenkins

15. EXTRAS
JENKINS DOCKER PLUGIN : ADD SLAVES CREATING CONTAINERS

16. EXTRAS
INTERACTING WITH DOCKER WITH DOCKER JAVA
DockerClient dockerClient = DockerClientBuilder.getInstance(dockerUrl).build();
Info info = dockerClient.infoCmd().exec();
List<Container> containers = dockerClient.listContainersCmd()
.withShowAll(false)
.exec();
CreateContainerResponse container = dockerClient.createContainerCmd("busybox")
.withCmd("touch", "/test")
.exec();
dockerClient.startContainerCmd(container.getId()).exec();
dockerClient.stopContainerCmd(container.getId()).exec();
<dependency>
<groupId>com.github.docker-java</groupId>
<artifactId>docker-java</artifactId>
<version>2.1.2</version>
</dependency>
Demo at : https://github.com/anthonydahanne/montrealjug_docker_java/tree/04_spring_boot_app_docker_api

17. LINKS OF INTERESTS
• Presentation links :
http://blog.dahanne.net/2016/01/31/docker-and-java-notes-from-the-montreal-jug-presentation/
https://github.com/anthonydahanne/montrealjug_docker_java
• Jenkins plugins
https://wiki.jenkins-ci.org/display/JENKINS/Copy+Artifact+Plugin
https://wiki.jenkins-ci.org/display/JENKINS/Support+Core+Plugin
https://wiki.jenkins-ci.org/display/JENKINS/Docker+build+step+plugin
https://wiki.jenkins-ci.org/display/JENKINS/CloudBees+Docker+Build+and+Publish+plugin
https://updates.jenkins-ci.org/download/plugins/
• DockerHub repositories
https://hub.docker.com/_/java/
https://hub.docker.com/_/jenkins/
https://hub.docker.com/_/tomcat/
https://hub.docker.com/_/maven/
https://hub.docker.com/r/anthonydahanne/terracotta-server-oss/
https://hub.docker.com/r/anthonydahanne/jenkins_with_plugins/
• Others
https://wiki.eclipse.org/Linux_Tools_Project/Docker_Tooling/User_Guide
https://plugins.jetbrains.com/plugin/7724
http://www.sonatype.org/nexus/2015/09/22/docker-and-nexus-3-ready-set-action/
https://github.com/docker/docker/issues/19396