This is a story about the struggles of adding a single iptables rule to ansible, which led to a night of insomnia and a series of incorrect assumptions about the root cause. While it’s uncommon to create a post mortem for a side-project cluster, I hope that sharing my experience will help others avoid making similar mistakes. I’ve also included all log and error messages in case you encounter similar issues. more...

I spent more than 20 years in a volunteer fire department which heavily influenced my leadership style as an engineering manager. I present my top five lessons learned from my time in leadership roles in the fire department, and how it helped me to shape the culture and motivate teams in my world of an engineering manager. more...

Simple if you know how to do it: Preventing Docker (Swarm) from opening ports to the outer world on Debian by overwriting the Docker network magic using iptables and nftables. more...

It took me 10 years to finish my PhD, so I would assume my procrastination skills are not that bad ;) … fortunately, nowadays, I use some basic rules to fight procrastination and have become quite efficient with it. The following three basic rules helped me a lot to organize myself. more...