Docker for Java Developers, from 0 to Dockerized

Repo to accompany my October 2016 talk at the Salt Lake City Java User's Group.

Slides: https://slides.com/ryanwalls/docker-for-java-developers-from-0-to-dockerized

Before talk starts

• Install Docker for Mac (https://docs.docker.com/engine/installation/mac/), Windows (https://docs.docker.com/engine/installation/windows/) or Linux (https://docs.docker.com/engine/installation/linux/).

Dockerizing your app

Look at Dockerfile.gradle and Dockerfile.maven for examples.

Gradle example

Build:

docker build -t "gradletest" -f Dockerfile.gradle  .

Run:

docker run -it -p 8080:8080 gradletest

Maven example

Build:

docker build -t "maventest" -f Dockerfile.maven  .

Run:

docker run -it -p 8080:8080 maventest

When running your build in CI/CD environment, look at https://hub.docker.com/r/ryanwalls/pom-version-parser for extracting your version number. (Always tag your docker images!)

Setting up Jenkins server

• Create barebones server with some form of linux
• Open port 80 (you can can do ssl termination with nginx later), I'm running in AWS so I had to alter my security group.
• Install Docker

curl -fsSL https://get.docker.com/ | sh

If you want to run without sudo, add your user to the docker group

sudo usermod -aG docker ubuntu

• Create a directory that you'll use to backup your Jenkins config e.g.

mkdir /home/ubuntu/jenkins

And make sure the jenkins user and group owns it (On ubuntu box I spun up, ubuntu user was already 1000:1000)

sudo chown -R 1000:1000 /home/ubuntu/jenkins

• (This could be improved, for demo only!) Let jenkins user access docker.sock

sudo chmod 777 /var/run/docker.sock

• Run jenkins with docker

docker run -d --name jenkins -p 80:8080 --restart unless-stopped \
-v /var/run/docker.sock:/var/run/docker.sock \
-v /home/ubuntu/jenkins:/var/jenkins_home \
ryanwalls/jenkins-with-docker:2.19.1-docker1.12.2

Copy password that is printed toward end of startup

• Navigate to http://
• Go through setup after authenticating with password copied earlier

Setting up your first build on Jenkins

• Create a new freestyle project