Dockerfile to create a Jenkins CI image with Java 8 and Java 11 support incl. installed docker-ce inside the Jenkins container to allow for docker container execution within Jenkins.
Depending on your firewall settings and if you want to use docker container inside your jenkins pipeline
(e.g. the famous testcontainers library) you might need to adapt your firewall settings to allow jenkins
to connect to container on the same host. The following command adds the required permissions for the
docker0 interface:
sudo ufw allow in on docker0 from 172.17.0.0/16 to 172.17.0.0/16