June 21, 2019

Catching support emails from my internet service provider

We all assume you cannot register admin, postmaster or support@yourisp.com, however, a Dutch provider let me do a similar thing. In Dutch we had an old spelling and a new one; pannekoek (old) and pannenkoek (new), which means pancake. So I tried to register klanteservice instead of klantenservice, which was still available! I didn’t look at it for years, my ISP changed its name, making me even catch more emails! Read more

June 20, 2019

Form manipulation

My regular domain registrar did not provide .nl domains, which made me look for Dutch registrars. At one of the cheapest registrars, the price was below 1EU for the first year. However, what if we could have this price for multiple years? Would the form proceed if we changed the value? Now only the checkout, do they validate? Contact registrar After I was able to proceed this checkout, I notified the company. Read more

June 13, 2019

Infrastructure as code for faster feedback loops

Investment banking and managing assets generally requires one to make decisions. Research has shown that making decisions based on data is better than gut feeling. We measure the output of our system by the metrics provided and decide and act upon them. But let’s look at the acting part. The old model is to change the business process (variables), wait for some data and see if the change had the desired outcome. Read more

April 11, 2019

Hack to enable WSL

Windows Subsystem for Linux (WSL) enables us to run Linux on a Windows 10 device. Even when developer mode and the windows store are disabled, you can run this when you can start PowerShell as an admin. Ubuntu/Debian/Kali via WSL If we have at least windows 10 1803 (see below), we can install WSL using the following steps: Download your distro (e.g. Ubuntu) as appx here Open PowerShell as Administrator cd C:\Users\YOUR-USERNAME\Downloads Add-AppxPackage . Read more

April 10, 2019

Prevent MITM proxies

Men In The Middle (MITM) proxies are used in some corporate environments for compliancy. You can spot this in your browser by inspecting the certificate. Sometimes you don’t want people to be able to do eavesdropping, which we can prevent using Nginx. Use the following config: ssl_protocols TLSv1.3; ssl_prefer_server_ciphers on; Note that this will not work for older browsers like Edge and IE. Chrome works fine. Debugging OpenSSL If you get an error stating no cipher match your Nginx may not have the latest OpenSSL version. Read more

February 10, 2019

List of self hosted web based IDEs

Developers write code in an integrated development environment (IDE), which is usually installed on their workstation. A WebIDE runs in the cloud, allowing one to work from any device that has a browser. In this article we only consider open source products. I’ve used a WebIDE for more than a year now and love it. It has allowed me to use a chromebook now and do everything in the cloud. Read more

February 6, 2019

Expose Nginx to public in Kubernetes

After getting kubernetes up and running and the dashboard online we proceed to getting our first service public to the world. When you do not use a load balancer provided by your cloud provider, kubernetes offers you two options for exposing ports: NodePort or using an ingress. Ingress is clearly the way to go, enabling you to have multiple services using the same port (this article explains the difference in more detail). Read more

February 3, 2019

Kubernetes dashboard basic auth

Kubernetes provides us with a proxy without TLS support or HTTP Basic authentication (BA). Using IP filtering (--accept-hosts) did not work on my VPS either. In this post I’ll show how you can access your dashboard with TLS and basic auth. This post can also be used to get your first k8s running on your Ubuntu machine/VPS. Get your cluster The following steps are based on this tutorial. You should have Ubuntu 16 or higher: Read more

January 28, 2019

Lightweight open source ERP

When developing software, teams often use an Agile process. Usually using a product backlog, providing a clear overview of the desired features. For my personal projects (which usually involve code) and other tasks in life, I did not keep to such a structure and was looking for an unified overview. The various notes; written, Google keep, in the README of the project etc. are not efficient enough. What I need is a good project management tool, to enhance productivity and create an overview. Read more

January 17, 2019

As a Developer and DevOps you can work on a chromebook

My technical colleagues never got why I wanted to work on a chromebook, they said, why limit yourself when it isn’t needed? People get it when I’m always in search for the hottest peppers or like to have muscle fatigue after exercise, but not when working with less specs. Initial setup Almost everything that I do, can be done in a browser or on a CLI (i.e. on my Linux VPS over SSH). Read more

Blog by lent.ink