Browsed by
Tag: software

WiFi 240V AC Led Dimmer – Speech Controlled

WiFi 240V AC Led Dimmer – Speech Controlled

I wanted to build my own WiFi dimmer, to connect my dinner table lights to Alexa (Amazon Echo Dot). The used parts are an ESP8266 (I used a Wemos D1 Mini Clone), an ATTiny45, some sort of power module to supply 3.3 volt, and a zero-cross-detector / Triac dimmer module.

Fluent Bit Elastic Search Data Type Filter

Fluent Bit Elastic Search Data Type Filter

Summary I have created a Fluent Bit LUA Filter to force proper data types to be send to our Elastic Search (log collector) Database, to prevent Elastic from rejecting the log records. GitHub Project: https://github.com/atkaper/fluent-bit-lua-filter-elastic-data-types Environment We are running a bunch of (on premise) Kubernetes clusters, all having around 20 nodes, with many deployments on it. The deployments use different technologies; Java, Kotlin, Node.js, GO, Python, C, … and quite some standard open source applications. Most of them have been…

Read More Read More

K8S Tiller/Helm History Cleanup

K8S Tiller/Helm History Cleanup

GitHub Project: https://github.com/atkaper/k8s-tiller-history-cleanup Introduction In our on premise Kubernetes cluster, we use Helm for a big part of our application / micro-services deployments. Helm uses an engine called Tiller (which is a deployment in the cluster). It executes the installs / updates / deletes, and it stores the results of deployments in the system as config maps. While migrating our applications to a new K8S cluster, we saw that we forgot to set a limit on the history which is…

Read More Read More

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,…

Read More Read More

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…

Read More Read More

Simple Tcp Vpn Over Ssh Socks

Simple Tcp Vpn Over Ssh Socks

Github Project: https://github.com/atkaper/simple-tcp-vpn-over-ssh-socks Poor-man’s VPN for TCP traffic over SSH dynamic socks tunnel, uses Linux/iptables Taken some TCP tunneling code from Christophe Devine, and turned it into a transparent socks proxy. This serves as a lightweight / poor-man’s VPN connection, to combine firewalled networks into one. Requirements; use linux on your end, and you need to be able to connect to an SSH server on the network you want to reach. And the local and remote network IP-ranges should NOT…

Read More Read More

K8S Network Test Daemonset

K8S Network Test Daemonset

Github Project: https://github.com/atkaper/k8s-network-test-daemonset Description An on-premise K8S (kubernetes) cluster needs a proper working virtual network to connect all masters and nodes to each other. In our situation, the host machines (vmware redhat), are not all 100% the same, and can not easily be wiped clean on new K8S and OS upgrades. Therefor we sometimes experienced issues in which the nodes or masters could not always reach each other. We did use the flannel network, which often caused weird issues. We…

Read More Read More

Pebble Watchfaces

Pebble Watchfaces

Github Projects: https://github.com/atkaper/pebble-simpleweek-nl and https://github.com/atkaper/pebble-simplicity-nl Pebble is a smartwatch, once created by a no longer existing company as a kickstarter project in 2012. See wikipedia for more info; https://en.wikipedia.org/wiki/Pebble_(watch) I do own a couple of these watches, and did create my own “watch face” for it. I still use the simpleweek-nl one, which displays the time, date, day, and week number. The “strange” number in the top left corner is indicating the year divided by 13 (4 week periods), as…

Read More Read More