Building docker images with Maven & Jenkins 2

This will use maven to build a jenkins master and slave docker image

After this you can use these docker images to start your own jenkins environment. The jenkins nodes can also build docker images or itself

docker maven plugin

https://github.com/fabric8io/docker-maven-plugin

introduction to this plugin

https://fabric8io.github.io/docker-maven-plugin/index.html

for a new VM follow these guides

• docker_oel7.md
• maven.md

all major utilities inside the image

mvn -v
java -version
docker -v

set memory

• export MAVEN_OPTS='-Xms2048m -Xmx2048m'

build with maven

• mvn package

test and verify

• mvn verify

run docker image

• mvm install

push image to registry

• mvn docker:push

Build your own environment

start the jenkins master

default which uses loopback adapter with devicemapper as storage-driver

• docker run -i -t --privileged -p 8080:8080 -p 50000:50000 --name jenkins_server jenkins/build-jenkins:latest

or with persistence

• docker run -i -t --privileged -p 8080:8080 -p 50000:50000 --name jenkins_server -v /vagrant/jenkins_persistence:/var/jenkins_home jenkins/build-jenkins:latest

with btrfs as storage-driver

requires /var/lib/docker btrfs filesystem

• docker run -i -t --privileged -p 8080:8080 -p 50000:50000 -e DOCKER_STORAGE_DRIVER='-s btrfs' --name jenkins_server jenkins/build-jenkins:latest

or with persistence

• docker run -i -t --privileged -p 8080:8080 -p 50000:50000 -e DOCKER_STORAGE_DRIVER='-s btrfs' --name jenkins_server -v /vagrant/jenkins_persistence:/var/jenkins_home jenkins/build-jenkins:latest

activate jenkins 2

• get password from the output or do this
• docker exec -i -t jenkins_server bash
• cat /var/jenkins_home/secrets/initialAdminPassword and get password for enable jenkins
• Use admin with that password for the slaves

start jenkins slaves with username/password

Replace XXXX with the acquired password

• docker run -i -t --privileged --hostname jenkinsslave1 --name jenkinsslave1 jenkins/build-jenkins-slave:latest -username admin -password XXXXX
• docker run -i -t --privileged --hostname jenkinsslave1 -e JENKINS_SERVER='x.x.x.x' --name jenkinsslave1 jenkins/build-jenkins-slave:latest -username admin -password XXXXX

with btrfs as storage-driver

requires /var/lib/docker btrfs filesystem

• docker run -i -t --privileged --hostname jenkinsslave1 -e DOCKER_STORAGE_DRIVER='-s btrfs' --name jenkinsslave1 jenkins/build-jenkins-slave:latest -username admin -password XXXXX
• docker run -i -t --privileged --hostname jenkinsslave1 -e JENKINS_SERVER='x.x.x.x' -e DOCKER_STORAGE_DRIVER='-s btrfs' --name jenkinsslave1 jenkins/build-jenkins-slave:latest -username admin -password XXXXX

Setup maven & java

• maven /usr/share/maven
• java /usr/java/jdk1.8.0_91

Usefull Docker commands

Show images

• docker images

Show instances

• docker ps -a

Remove instances

• docker rm XXXXX

Remove all instances

• docker rm $(docker ps -a -q)

Remove image

• docker rmi XXXX

Remove all images

• docker rmi $(docker images -q)

Possbile Errors and solution

[ERROR] DOCKER> Driver devicemapper failed to remove root filesystem 32a7bdd7c4eae02ce72107848922811b9824554e52b2fe1034a12e6f391c4868: Device is Busy (Internal Server Error: 500)

Probably because of the devicemapper as storage-driver

find /var/lib/docker -name 32a7bdd7c4eae02ce72107848922811b9824554e52b2fe1034a12e6f391c4868
rm -rf those files
systemctl restart docker
docker rm $(docker ps -a -q)