Docker file extending official Jenkins image, add docker support(share host docker)

Dockerfile

FROM jenkins/jenkins:lts
# if we want to install via apt
USER root
ENV DOCKERVERSION=18.03.1-ce
RUN curl -fsSLO https://download.docker.com/linux/static/stable/x86_64/docker-${DOCKERVERSION}.tgz \
  && tar xzvf docker-${DOCKERVERSION}.tgz --strip 1 \
                 -C /usr/local/bin docker/docker \
  && rm docker-${DOCKERVERSION}.tgz
RUN groupadd docker
RUN usermod -aG docker jenkins
RUN chmod -v a+s $(which docker)
# drop back to the regular jenkins user - good practice
USER jenkins

And use this to run

docker run -d \
-v jenkins_home:/var/jenkins_home \
-v /var/run/docker.sock:/var/run/docker.sock \
-p 8089:8080 -p 50000:50000 \
-e JENKINS_OPTS="--prefix=/devops" \
--name my-jenkins \
my-jenkins