About me

I am Vincent, a freelance software engineer living in Berlin. Write me an email or contact me on Telegram if you want to hire — or have a coffee with me. I have years of experience building web applications with a focus on usability and using Javascript and/or Python. Here is my cv. Some of the projects I have been working on are: okdone, a service that provides you with a personal assistant to boost big and small projects Metawahl, an tracker for changes in the stance of political parties in Germany mietlimbo, an online assistant for Berlin’s rent cap Aula, a liquid democracy system for high schools You can find more of my code on my GitHub.

How to Anonymize Nginx Access Logs

Web server access logs keep track of the addresses of computers that made connections to your server - in other words: Who is visiting your web site. I always thought that it’s not really necessary to record the individual IP addresses of everyone - it’s private data and you usually don’t even use it. Also it may even be a violation of the European GDPR directive.

Unfortunately the popular web server nginx is preconfigured to record this information and it’s not trivial to turn the feature off. This is especially so if you want to keep some form of identification in order to be able to identify groups of requests in your access log that originated from the same computer (e.g. when debugging).

These instructions let you configure your nginx server to record IP addresses in a »fuzzy« form, which is anonymous but still allows some debugging.

Metawahl bei Jugend Hackt

Bei Jugend Hackt, einem Event für junge Menschen, die sich fürs Basteln und Programmieren interessieren, habe ich am letzten Wochenende Metawahl vorgestellt. In dem Video stelle ich kurz das Projekt vor und gebe dann einen ultrakurzen Überblick, wie man sich mit einem Crawler Informationen aus dem Web zusammensuchen kann um daraus etwas neues zu bauen.

Beobachtungen zum Wahl-o-Mat Bayern 2018

Auf Metawahl gibt es jetzt eine Prognose zur gewählten Politik bei der Landtagswahl in Bayern diesen Monat. Interessanterweise gab es wieder hauptsächlich Fragen, die so, oder so ähnlich, auch in anderen Ausgaben des Wahl-o-Mat gestellt wurden.

Ein paar Sachen sind mir dabei gleich aufgefallen:

Humino: Accessing Soil Data With a Telegram Bot

I have written about building an Arduino-based soil monitoring system and how to predict time until next watering with linear regression. Yet, to see these results I had to shutdown the Arduino every morning, remove the SD card it was logging data to, copy that to my computer and run the analysis script. That should be wireless!

So I setup a bot for Telegram messenger that I can ask for the current measurements.

Humino: Predicting when plants will need watering

In the last post I wrote a follow-along to building an Arduino-based soil monitoring system. In this post I want to write about how I used linear regression to predict how much time is left until the plants are dry again.

  Hibiskus        wet (56.40%)
  Walnuss         wet (50.18%)
  Dieffenb B      2 days (53.21%)
  Dieffenb H      3 days (64.22%)
  Yucca           7 days (45.06%)

Edit: After running this for two weeks I found the predictions to be very unreliable and not very useful. Sometimes the sensor values fall continuously and then it works great, but often the influence of sun/warmth on the readings makes them unpredictable.

Humino: Monitor Soil Humidity with an Arduino

Another thing I wanted to have since I was maybe 5 years old? PLANTS with MICROCHIPS! Probably the hardest part about keeping my green friends alive is making sure that they get enough water even when I am busy with other stuff, on vacation, etc etc. Now that there are cheap Arduinos to have it has gotten quite easy to realise this!

Metadata Petting Zoo

Cellphones make available large amounts of personal information about you in public airspace. I propose building a metadata petting zoo to raise awareness for this issue and some possible solutions. This broadcasting of metadata is a necessity for you using your phone. It cannot be disabled until cellphone technology is recreated from the ground up with privacy in mind. It doesn’t require hidden surveillance technology but makes use of the most common network systems such as Wifi, LTE, GSM and Bluetooth.

An Independent Blog using Hugo and Dat

Everyone should have a button on their computer that reads “make a new website”. This is one of the things that the Dat project is working on with the Beaker browser: Making it easy to self-publish content on the web without using centralized infrastructure services from the likes of Google and Amazon. As I create this blog using Hugo, a static site generator, I thought it should be pretty easy to make it available on Dat.

Privacy Friendly Blog

Vincent Bernat writes about the replacements he used to make his blog more privacy aware instead of relying on an abundance of external services. Whatever.

read A more privacy-friendly blog