icinga2telegram

The Telegram bot API makes it really easy to use Telegram to send automated messages to yourself (or other people). A while ago I started to use this to send Icinga2 alerts to me.

Several other people implemented Icinga2-Telegram notifications by writing a simple Bash script. Most of the time this works but there are a few things I do not like about the Bash solutions:

  1. They use two scripts with almost the same content.
  2. Bash can screw up really bad when your alert output contains special characters.
  3. The Bash solutions are based on environment variables. This does not work natively with Icinga2 director as it only supports arguments in command definitions.

As a solution I wrote a small Python tool to handle Icinga2 notifications: icinga2telegram.

Screenshot of icinga2telegram

Obviously the Python implementation has a bigger footprint than the Bash solution. It requires a Python interpreter and installs several Python packages as dependencies. This could be a problem for an embedded system with very limited resources but most Icinga2 instances run on powerful machines and the icinga2telegram footprint does not matter there. In return you get a single maintainable and robust script that you can use for host and service notifications.

If you want to learn more about icinga2telegram you can check out the source code and documentation at GitHub.

OSMC 2018

From the 4th of November to the 7th of November two coworkers and I attended the OSMC 2018 in Nuremberg. We started the first day with a Prometheus workshop by Julien Pivotto. He gave us a nice overview how Prometheus works and we were able to try everything out in real time.

After the workshop we had two days of interesting talks about different monitoring related topics followed by a hackathon on the last day. During the hackathon I was able to work on a new IcingaWeb2 feature and hopefully it will find its way into the upstream code :)

During the second day of the conference I had the chance to give a lecture about our Icinga2 setup at SysEleven: Scaling Icinga2 with many heterogeneous projects – and still preserving configurability.

My slides are also available at SlideShare and all videos and photos of the amazing conference are available at the OSMC archive.

Record a GIF with Linux

I found a cool tool called Peek to record a GIF with linux. Unfortunately it does not work well with i3.

So I ended up using byzanz-record instead. My only issue with byzanz is that it requires you to pass x and y coordinates when you want to record a selection of your screen and usually I do not like to count pixels before every recording…

Luckily someone wrote xrectsel, a simple tool to get the geometry of a selected screen region. By combining xrectsel and byzanz it is possible to record a nice GIF with i3 and probably all other window managers:

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byzanz-record                                        \
  --cursor                                           \
  --verbose                                          \
  --delay=2                                          \
  --duration=10                                      \
  $(xrectsel "--x=%x --y=%y --width=%w --height=%h") \
  /tmp/recording.gif

To make my life easier I put it in a small shell script called gif.sh:

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#!/usr/bin/env sh

[ $# -lt 2 ] && \
  echo 'You have to pass a duration in seconds and a filename: "gif.sh 10 /tmp/record.gif"' && \
  exit 1

byzanz-record                                        \
  --cursor                                           \
  --verbose                                          \
  --delay=2                                          \
  --duration=${1}                                    \
  $(xrectsel "--x=%x --y=%y --width=%w --height=%h") \
  "${2}"

Record a GIF

Hello World 2.0

Hello again, I am back!

In 2011 I started my blog fotoallerlei.com. In the beginning it was more about photography but over the years my focus shifted more and more to tech related blog posts. In 2018 the GDPR came along and because I did not want to spend my time with all the new internet rules I decided to take my blog offline.

After a few months I was finally able to catch up with the new regulations and I also realized that I miss my blog. So I replaced my previous Wordpress installation with Hugo - a simple static site generator. Maybe I will repost some of the old content if it is still relevant.

From now on I will use my blog again to dump my personal notes for future use. And maybe they will be useful for some strangers in the internet. Most of the content will be tech related but we will see what the future holds.

34C3 - I talked about OmNomNom

Between Christmas and New Year’s Eve I attended the 34C3 in Leipzig. I visited the congress before but it was the first time that I gave a presentation (at the congress) myself. At the last day of the 34C3 I talked about OmNomNom, my open source Telegram canteen chatbot, as part of the Lightning Talks. I explained the architecture of the software and the infrastructure I use to run and deploy the bot.

All talks were recorded, you can check out my talk in the embedded video. It starts at 01:24:45.

If the video does not work you can check YouTube or media.ccc.de. Despite the fact that my talk was a little too long for the five minutes time slot it was a nice experience to talk on such a big stage and luckily I was done with the important part of my talk when the time was up.