Posts on goroot

Automated tasmota backups

Sat, 04 Dec 2021 14:28:10 +0100

My smart home heavily relies on tasmota [arch] powered smart devices to work properly. While the tasmota software itself is rock stable and barely leads to any downtimes, the hardware it is running on isn’t quite. What do you do if you don’t have any tasmota backup and the device breaks? Would you be able to restore the configuration of dozens or even hundreds of devices just by remembering?

How to use Visual Studio Code on your iPad

Thu, 29 Jul 2021 13:19:52 +0100

I recently came across the problem that when being on vacation I don’t have my main computer available. I usually only go on vacation with a light weight set of IT equipment, which is in this case my iPad Pro and a few cables and chargers. This is a conscious decision since I don’t want to invest too much - in the best case no time at all - into sitting in front of my computer. How ever, there are situations where you need to do a quick fix: for example one of my websites breaking or any other service not running anymore. Even if this would be theoretically possible it is hard to fix these things on a smart phone without having an IDE like VSCode [arch] in place.

Presence detection: Bee in a box

Thu, 22 Jul 2021 21:31:21 +0100

The ‘bee in a box’ algorithm enables you to detect presence in a given area of your smart home. It will enable your smart home system to know whether in a given area anybody is present or not. No special sensors or other additional hardware is required to do so.

Bee in a box algorithm: The theory

Imagine somebody handing you over a small box made out of cardboard. On the top side of the box, there is a yellow warning symbol ‘Warning: there might be a bee inside’.

ESP32 as BLE Gateway for Xiaomi Mijia BLE Temperature & Humidity Sensor

Thu, 01 Jul 2021 14:37:30 +0100

Problem statement

~~Too many unused BLE sensors, too much time during the COVID-19 lockdown - lets add more sensors! Just because we can…~~

No seriously. I struggled a lot with too much humidity in the air in several areas of my house. After having a hot shower in the bathroom, the humidity condensed at the window, increasing the risk for mold growth. In the basement where our food supplies are stored, we had issues with salt getting wet. And since I also own a reef-tank connected to my smart home system which cools the water using evaporation, the humidity in the living room is also a very interesting measurement. So wh

Monitor the pH of your reef tank with Tasmota

Mon, 01 Mar 2021 21:09:03 +0000

Monitoring water values of your fish tank is essential. To keep your reef-ecosystem alive, several dozens of water values need to be measured. This can be quite annoying to do that manually all the time. So I just started automating the measurement of them via Tasmota [arch]. One of the leading indicators for a fish tank is the pH level of the water. Measuring the pH level gives you a good indication for several other water values as well.

Network segregation: IoT vs NoT networks

Thu, 18 Feb 2021 17:32:40 +0100

IoT devices became quite popular throughout the last years. Everything is connected, anytime. What sounds like a good idea, might actually result in a security hole in your network. As only the vendor knows what a device is actually doing, your IoT devices might bring some features with them that you don’t like.

What is the problem with my IoT device?

The short answer is: you own it, but you don’t control it. But…

Unattended docker container updates

Sat, 13 Jul 2019 14:32:03 +0000

To keep your container infrastructure up to date and therefore secure, there are two primary objectives that you need to achieve:

Keep the host‘s operating system up to date
Keep the content of your containers up to date

Update the operating system

Updating your operating system is quite straight forward. Just use the well known package managers to do the job for you. E.g. for Debian this would be as easy as running apt-get update && apt-get upgrade on a regular basis.

Using the cloud as panic room

Sat, 03 Feb 2018 18:41:00 +0000

Time to do something about it, and also about all other scenarios that threaten your digital heritage. Can the cloud be the safe place to backup all your data? But doesn’t uploading backups to the cloud also mean that others might be able to access it? In this article we will show a disaster recovery concept that you can use to backup infinite data amounts: It is free, easy to set up, and bullet prove.

Docker Image Review: jwilder/nginx-proxy

Mon, 29 Jan 2018 10:18:00 +0000

Ever wondered wether there is a good alternative for scenarios, where a full featured ingress proxy would be overkill? Here it comes: jwilder/nginx-proxy. The image can especially be useful when setting up an ingress concept for the first time. Nginx [arch] is well known in the world of classic server administration and web hosting. So why not use your familiar web server also in your containerised environment? Compared to full featured ingress routers like Traefik [arch] the image enables you to reuse your existing know-how, and also some of your configurations. The concept of a ingress router is similar to a reverse proxy. It is to hide all other services behind a single container, as you would do with a reverse proxy. The advantages are obvious: You don’t have to care about things like Encryption or authentication for each and every service separately. It also gives you the possibility to do things like load-balancing or gathering statistics across all your services.

Docker containers are insecure

Sun, 14 Jan 2018 12:12:00 +0000

Everybody knows how to keep a linux box updated. It is also common sense that running things in docker containers is more secure by definition. After all they isolate services from each other. So if you are running containers on a fully patched host, there should be no security holes at all. Not even close! Keeping containers up to date is a total different thing. That brings up the questions how to keep your containers up to date, and how to decide wether containerising is really worth it in your scenario.

Starting on a blank page

Thu, 11 Jan 2018 17:48:00 +0000

A little bit of History

The blog initially started in 2014 and was online till late 2016. I primarily focused on Ham Radio and IoT content these days. These topics were appreciated by many readers. Nevertheless, the old blog had to come to an end as my interests also changed over time. I was simply not able (nor willing :-)) to invest the time necessary to write high quality articles on topics that are no longer my primary focus.