tl;dr: Service for generating Dockerfile for Jenkins slaves is up and running here: http://docker-jenkins-slave.herokuapp.com/ .
Docker jenkins slave
The beginning of story is here: http://antigluk.blogspot.com/2013/10/docker-jenkins.html [russian].
Abstract: If you want to build your project on different environments (e.g. Jenkins installed on Arch Linux, and you want to build RPM on CentOS 6) with jenkins, but you don't want to use virtual machines, which is inefficient wasting of RAM and CPU, using Docker is good idea.