Recording Log Appender for Java Unit Testing
A short post about a simple Java Utility class to help out in Unit Testing the proper functioning of log statements in code under test.
WiFi Temperature Sensor
Building a WiFi temperature sensor, and showing the data as graph. Using DS18B20, WeMos D1 mini ESP8266, InfluxDb, Telegraf, Grafana.
Send new created Jira ticket info to MS-Teams Channels
Summary We are using (self hosted) Jira (the Atlassian Issue Tracker / Scrum / Kanban Board) at the office. And we wanted to receive a chat notification for each newly created ticket, to be received in Microsoft Teams Channels. Teams is a collaboration messenger tool like Slack or RocketChat. Jira can send new ticket/story creations using a web-hook to external tools. The web-hook sends a Jira specific JSON payload, no configuration options possible. The project you are looking at, consists…
P1 Energy Meter Reader using Python in Docker
A python script, running in a docker container, to read energy consumption and back delivery data from the digital “smart?” meter (as is installed in many homes in the Netherlands). Storing it in mysql for further use.
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
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…
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…
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,…
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…
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…