Blog
From time to time I will post here some interesting findings I made or write something about things I’m working on.
Y2038, glibc and /var/log/lastlog on 64bit architectures
On January, 19th 2038 at 03:14:07 UTC the 32bit time_t counter will overflow. For more information about this I suggest to start with the wikipedia Year 2038 problem article. That problem is long known and several groups are working on a solution for 32bit systems, but many people don’t know that pure 64bit systems could be affected, too. The general statement so far has always been that on 64bit systems with a 64bit time_t you are safe with respect to the Y2038 problem.
Radfahren in Fürth
Ich bin in Warendorf geboren und aufgewachsen. Entsprechend konnte ich natürlich schon vor der Einschulung Fahrrad fahren und es war auch völlig normal, das wir bei fast jedem Wetter mit dem Fahrrad zur Schule gefahren sind. Gut ausgebaute, teilweise beleuchtete Radwege haben die einzelnen Dörfer auf direktem Weg miteinander verbunden. Heute würde man einige davon wohl Radschnellweg nennen. Also ein Zustund, wie ich ihn hier in Fürth und Bayern wohl zu Lebzeiten nicht mehr erleben werde.
Hugo Photoswipe5 Gallery Theme
Over the last days I create a gallery displaying images in a lightbox/carousel gadget. It’s a css image gallery in Hugo using shortcodes, for the optional lightbox/carousel gadget I’m using PhotoSwipe 5.3.x and Dynamic caption plugin. This theme can create a gallery of all images in a page bundle. It uses Hugo Page Resources, which allows to create thumbnails on the fly, with a configurable thumbnail size. It’s based and inspired by the easy-gallery theme from Li-Wen Yip.
Y2038, glibc and utmp/utmpx on 64bit architectures
On January, 19th 2038 at 03:14:07 UTC the 32bit time_t counter will overflow. For more information about this I suggest to start with the wikipedia Year 2038 problem article. That problem is long known and several groups are working on a solution for 32bit systems, but many people don’t know that pure 64bit systems could be affected, too. The general statement so far has always been that on 64bit systems with a 64bit time_t you are safe with respect to the Y2038 problem.
Y2038, glibc and wtmp on 64bit architectures
On January, 19th 2038 at 03:14:07 UTC the 32bit time_t counter will overflow. For more information about this I suggest to start with the wikipedia Year 2038 problem article. That problem is long known and several groups are working on a solution for 32bit systems, but many people don’t know that pure 64bit systems could be affected, too. The general statement so far has always been that on 64bit systems with a 64bit time_t you are safe with respect to the Y2038 problem.
Export MQTT Topics to InfluxDB
Intro The goal of this blog series is to collect the sensor data of different IoT devices via MQTT, store them in InfluxDB 2.6 and visualize them with Grafana. The previous blogs from this series: Grafana with podman kube Setup MQTT Broker, IoT Devices and Security InfluxDB v2 as Datasource for Grafana In this post I will describe how to collect the sensor data via a MQTT Broker and store them in InfluxDB 2.
InfluxDB v2 as Datasource for Grafana
Intro In the last blogs (Grafana with podman kube and Setup MQTT Broker, IoT Devices and Security) I explained how to setup Prometheus, Grafana and Mosquitto as MQTT Broker to visualize the data from IoT devices, mainly from Shelly. In this blog I will explain how to setup InfluxDB v2.6 and use it as additional datasource for Grafana. Why Prometheus and InfluxDB? Many of my devices send only a new MQTT message with new values, if the difference to the old value is big enough.
Setup MQTT Broker, IoT Devices and Security
Intro Some time ago I heard an interesting talk: The S in IoT stands for Security. There is no ‘S’ in IoT? Correct, and exactly this is very often the problem. Even if you think “My IoT devices are all behind my firewall, I’m safe”: No, because most attacks happens from inside the network, by malware, social engineering attacks, unhappy employees or bad friends, … So my goal is, to setup my MQTT broker which is as safe as possible.
Grafana with podman kube
Background For a long time I have been using a containerized version of Munin to monitor some of my devices. But there are many things I can’t do with it and for many new tasks I would have to write code first, while there are often more than enough solutions for Prometheus and Grafana. So far I have only used it for demos of openSUSE Kubic and openSUSE MicroOS at conferences and trade shows (like SUSECon19).
New Homepage Design!
After 21 years it was time for a redesign of my homepage. Not everything is converted yet, but I’m working on it! This time I wanted to make it easy and not create an own theme, but use the static web page generator Hugo and a nice, fitting theme from the gallery. The absolute majority of free themes didn’t fit for my use case or I didn’t liked them. The best fitting one was the personal-web theme, but as always: if you try to use it for your ideas to have something own, I reached pretty fast the boundaries of this theme.