Felix Frank has used and programmed computers for most of his life. During and after his Computer Science diploma, he gained on-the-job experience as a system administrator, server operator, and open source software developer. Of his 10-year career, he spent 5 years as a Puppet power user. For almost a year, he intensified his learning by contributing source code and actively participating in several conferences. This is his first foray into writing books and is a work of great effort and sacrifice.