Jenkins Docker with Docker support on Ubuntu 16.04.md

Step 1

docker run -d \
  -v jenkins_home:/var/jenkins_home \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -p 8080:8080 -p 50000:50000 \
  --name jenkins \
  jenkins/jenkins:lts 

What it does:

• use jenkins:lts, read https://github.com/jenkinsci/docker/blob/master/README.md
• mount the host machine's Docker socket in the container /var/run/docker.sock:/var/run/docker.sock, read https://getintodevops.com/blog/the-simple-way-to-run-docker-in-docker-for-ci
• name it jenkins, important later

Step 2

• spawn shell of container, however use method recommended here: from https://stackoverflow.com/a/54723144 docker exec -t -i -u root jenkins /bin/bash

Step 3

• install docker binaries inside the container, note: docker is still used from the host socket! read https://getintodevops.com/blog/the-simple-way-to-run-docker-in-docker-for-ci

apt-get update && \
apt-get -y install apt-transport-https \
     ca-certificates \
     curl \
     gnupg2 \
     software-properties-common && \
curl -fsSL https://download.docker.com/linux/$(. /etc/os-release; echo "$ID")/gpg > /tmp/dkey; apt-key add /tmp/dkey && \
add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/$(. /etc/os-release; echo "$ID") \
   $(lsb_release -cs) \
   stable" && \
apt-get update && \
apt-get -y install docker-ce

Step 4

• from https://stackoverflow.com/a/54723144

# inside jenkins container:
usermod -a -G docker jenkins
docker restart jenkins