Mario Kleinsasser

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Senior Cloud Solution Architect, SysOps, Speaker, Docker Community Leader, Cloud Native Citizen, Open Source Evangelist - Working @STRABAG_SE IT

Hello and welcome to my personal profile page! On this page I would like to give you some information about me, my progress, my experience and my projects.

I am the team leader of a small web-hosting department of a large construction company. Since more than 15 years I am working as a DevOps and I try to push the automatization to a higher level. When theory meets practice things are often not working as expected. Combining the actual theoretical technical developments with real world IT problems and creating something new out of it is my passion. The art is to solve real world IT problems by transforming the theory into working and durable solutions.


  • IP Networking
  • DNS
  • Firewalls
  • Load Balancing
  • Microservices
  • RESTful APIs
  • SaaS/PaaS/IaaS
Languages, Operating Systems & Tools
  • Golang
  • Python
  • Bash
  • Perl
  • linux
Platform Development & Administration
  • Apache
  • Git
  • Puppet
Containers & Cloud


Post - Build a Docker Swarm on AWS with Ansible in 1 minute and 47 seconds

Is it possible to build a five node (3 manager nodes, 2 worker nodes) Docker Swarm in under 2 minutes? Yes it is! Some weeks ago, Hennnig Jacobs who works at Zalando Technology, posted a Tweet where he referenced an article he wrote called “Why Kubernetes?”. This article covers another post, “Maybe You Don’t Need Kubernetes”, written by Matthias Endler who works at Trivago. Read more...

April 2019

Post - DevOps Gathering 2019

For the second time I attend to the DevOps Gathering as a speaker. This year I shared the stage with Alexander Ortner, a colleague and friend of mine, and we did our talk together. Also Bernhard Rausch was with us, but we have to leave him back during our travelling challenge. 😮 Read more...

March 2019

Post - 2019

This weekend, from the 25th until the 27th of January, the took place at the Faculty of Information Technology Brno (Czech Republic) and I’ve got the chance to attend. As an Open Source addicted community driven conference, which is mainly sponsored by Red Hat there was no ticket charge, but a free ticket registration was required. Read more...

January 2019

Post - Site Reliability Engineering

The two weeks Holidays vacation is over, we are back at work and the Docker Swarms ran fully unattended without a single outage during this period! For every IT engineer reliability may be something different because it depends upon which goals you have to achieve with your team. Read more...

January 2019

Post - Condense DockerCon EU 2018 Barcelona

This year we had the great opportunity to attend to DockerCon EU 2018 at Barcelona with four people. Two of us, Alex and Martin are developers, and Bernhard and I are operators so we did a real DevOps journey! The decision to go with both teams, in terms of DevOps, was the best we ever made and we are very thankful that our company, STRABAG BRVZ supported this idea. In fact, there were a lot of topics which were developer focused and in parallel there were also a lot of breakouts that were more operator focused. So we’ve got the best of both world Read more...

December 2018

Post - Running Play with Docker on AWS

Some weeks ago I dived a little bit into the Play with Docker GitHub repository because I would like to run Play With Docker (called PWD) locally to have a backup option during a Docker Meetup if something would be wrong with the internet connectivity or with the Docker prepared workshop sessions. Read more...

December 2018

Post - Docker, block I/O and the black hole

Last week, Bernhard and I had to investigate high disk I/O load reported by one of our storage colleagues on our NFS server which serves the data for our Docker containers. We still have high disk load, because we are running lots of containers and therefore this post is will not resolve a load issue but it will give you some deep insights about some strange behaviors and technical details which we discovered during our I/O deep dive. Read more...

October 2018

Post - Writing a Docker Volume Plugin for CephFS

Currently we are evaluating Ceph for our Docker/Kubernetes on-premise cluster for persistent volume storage. Kubernetes officially supports CephRBD and CephFS as storage volume driver. Docker does not offer a Docker Volume plugin for CephFS currently. Read more...

September 2018

Post - Docker Swarm Network – Down the Rabbit Hole

Last week we tracked down a recurring problem with our Docker Swarm, more exactly with the Docker overlay network. To anticipate it, there is a merge which might fix this, but not for Docker-CE 18.03 . The pull mentioned is also not included in Docker-CE 18.06.1 but it is already merged into Moby and part of Docker-CE 18.09.0-ce-tp5 which means that the fix should be available with Docker-CE 18.09. Read more...

August 2018

Post - A way to DevOps - About failure culture and the five whys

After my talks I am regularly asked how we managed it to tear down the wall between Operations and Development. Read more...

February 2018


A collection of projects authored by me, and likely shared out with the community as an open source project.


A simple Golang template renderer with sprig template extensions.


Kubernetes - The roguelike way!

Build up Kubernetes the roguelike way on premise. No scripts. No clouds. No magic.


Docker Bosnd

bosnd, the boatswain daemon. Dynamic, Docker Swarm based configuration file templating for all kinds of services (Apache httpd, Nginx, HAProxy, ...) made real.



The smsgateway is a Python3 based software solution to send SMS with HTTPs REST calls (web interface) using commodity hardware.


Open Source Contributions

A collection of efforts to which I contributed, but did not create. Contributing back to Open Source projects is a strong passion of mine, and requires a considerate approach to learn norms, standards and approach for each community for a successful merge!


Summary of CodeDNS pull requests


Docker Machine

Summary of CodeDNS pull requests



Article - Macht der Einsatz von Kubernetes wirklich immer Sinn? - Artikel in der Spezialausgabe des Entwickler-Magazins

Kubernetes nur wegen Kubernetes einzusetzen oder weil der Einsatz ohne Grund als notwendig erachtet wird (Hype), stellt den falschen Ansatz dar und kann zu einem sehr großen Anstieg der Komplexität führen, weilcher am Ende sowohl Entwickler als auch Operatoren überfordert und schlussendlich frustriert.

May 2019

Talk - C4 - Continuous Culture Change Challenges (DevOps Gathering 2019)

In less than a year we have managed to change our working culture from throwing informations over the great wall between Dev and Ops to a failure tolerant, management accepted honored culture. We have enabled colleagues to unleash their bygone forgotten strengths... -

November 2018

Talk - GitOps: DevOps in Real Life. (Vienna DevOps & Security Meetup)

Container-Technologien in einem On-Premises Umfeld einzuführen bringt viele Veränderungen mit sich. Besonders die Evolution in der Zusammenarbeit zwischen den Teams, sowie der ständige Wandel und die Weiterentwicklung der Technologien, führen zu immer neuen Herausforderungen aber auch zu immer neuen, kreativen und innovativen Lösungen.

July 2018

Talk - Docker: DevOps unleashed. (DevOps Gathering 2018)

Ops are doomed in the quicksand of enterprise. We gained experience across our Docker journey which I would like to share. I will show you that it is possible to run Docker On-Premise and I will show you that it is worth it because you will be able to escape the - I have no time daemon -.

February 2018


Docker Community Leader

Docker Community Leader and Docker Meetup organizer south Austria.

November 2017 - Present

Teamleader Continuous Integration


Team Leader

August 2000 - Present


University of Applied Sciences Kapfenberg

Master of Business Arts
IT Law and Management
2015 - 2017

University of Applied Sciences Salzburg

Bachelor of Science
Information Technology and Systems Management
2011 - 2014
Nifty tech tag lists from Wouter Beeftink