Duplicate unprotected Mifare Classic NFC Card

Duplicate unprotected Mifare Classic NFC Card

Where I live, they have changed the way they pickup garbage. Only plastic, paper, and green-stuff will be picked up (in separate bins). And the ordinary (formerly grey) trash you need to bring to one of the central bins in the neighborhood (and glass you have to bring to the bins at the shopping mall). So, those central “grey” bins… to prevent just anyone from dropping stuff in there, you need to use an RFID badge to open it up….

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Sonoff Firmware Update – Lava-lamp Switch

Sonoff Firmware Update – Lava-lamp Switch

I have a lava-lamp, which should not be on for more than 5 or 6 hours at a time. So I decided to move it from switching on/off manually to something a bit more automated. For this I reprogrammed a Sonoff WiFi switch (based on the ESP8266). Now it can be controlled via voice commands (via Alexa / Amazon’s Echo Dot), and via some simple CURL (Wifi) command line call’s. The curl’s are put in a cron (timer) process on…

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WordPress Plugin – Meta Robots

WordPress Plugin – Meta Robots

Mini project of the day… I did create a tiny WordPress plugin, to add a meta robots header to some of my pages, to prevent them from being indexed by google and other search engines. So without further ado, here’s the source code, to be put in a file: wp-content/plugins/meta-robots/meta_robots.php in your WordPress installation folder: After adding this code, go to your plugin configuration, and enable the plugin. It should show up in the list automatically. To enable the header,…

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3D Printed Bathroom Cabinet Shelf Finishing Strip

3D Printed Bathroom Cabinet Shelf Finishing Strip

The shelves in my bathroom (mirror) cabinet do have fixed positions. So when trying to put an electric (standing) toothbrush in there, it would not fit. So I just took out a bit of one of the shelves. And this left an ugly front side of the shelf, which needed some solution. First attempt was just using a bit of electric isolation tape; Of course this works fine (a bit shabby, but it’s juts a normally closed cupboard). But as…

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SEO Wisdoms

SEO Wisdoms

Or: how to get your data to be found on the internet… Intro So… at the office we were moving from one web mail/storage system to another (too bad, not getting any better), and we had to go through our old documents to determine what to keep. And in the pile of stuff to check, there was a nice photo of some Search Engine Optimization (SEO) rules which will (probably?) never get old. We did have these rules up on…

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Antique Game Button Setup

Antique Game Button Setup

Today I was cleaning out an old moving-box, and found a very old small project of mine 😉 It’s a set of game / quiz buttons, which record who did press first. There were only two buttons connected, but the circuit was suitable for 4 of them (two were cut off). There’s no circuit diagrams or software available, it’s just a bunch of images and movies to show the old stuff. It’s a simple setup, you can almost guess the…

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Docker Log Plugin

Docker Log Plugin

A quest I took at 2 November, making my own docker log plugin. Suitable to share with everyone. At the office, we are mixing docker-only hosts, with on-premise kubernetes clusters. For example our databases do run better / more stable on plain docker hosts, with no kubernetes intervention. That’s mainly due to the sub-optimal distributed storage in our on-premise cluster. But… we do want to send all of the logs from both kubernetes and docker hosts to a central logging…

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Wifi Controlled Alert Light

Wifi Controlled Alert Light

Intro Now why would I want to create an alert light? 😉 The use case I had in mind was work related; in our team we do monitor a bunch of kubernetes/docker server clusters, a set of software build tools/services, and an oauth secured open-api-gateway. To keep an eye on this during office hours, we have some big dashboard monitors in the room, showing nice graphs and red/green alert boxes. However, sometimes when you are working on something, it takes…

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K8S Check Certificate Chains

K8S Check Certificate Chains

Github Project: https://github.com/atkaper/k8s-check-certificate-chains Ingress/nginx (running in Kubernetes / K8S) does not like silly certificates, therefore I created two scripts to find wrong ones. The script get-all-k8s-certificates.sh retrieves all certificates from kubernetes, and the check-certificate-chains.sh script verifies the chain’s are complete and in proper ordering. Added md5 hash check on crt and key file to verify the two belong to each other. The check-certificate-chains.sh just reports on WRONG certificates. Run with “-v” option to also show OK’s. Thijs.

Fast Character Replace Contest

Fast Character Replace Contest

At the office, we have quite a bunch of Java developers. However, because we are quickly growing (way, way, way too quick in my opinion), there was an intake exam created, as part of sourcing in new Java coders from external companies. One of the questions on the intake was an interesting one, so we took it upon ourselves (the existing oldies) to try creating not the most beautiful, but the FASTEST way to get the job done 😉 See…

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