I was getting this x509: malformed serial number error in my Go application when I tried to read a public key of a specific format. This error was very misleading, and it took me quite a while to figure it out. Most of the time was spent because of bad…

Flaky tests can give you a lot of trouble. They may pass today but fail tomorrow, randomly blocking your CI pipeline from successful execution, your merge requests from merging, and causing general aggravation. Finding the reason for flakiness is never simple, it’s hard to estimate how long it will take…

This post is not quite ordinary for my blog, as it’s not directly related to software engineering. But I suddenly decided to return to this online puzzle game Notpron decades later, and now it doesn’t go out of my one-track mind. So I just need to share it. …

Here’s a tiny tip on how to test your Go application inside a Docker container. Suppose you’re writing an application in Go, and you want to test how it will behave inside a container. Of course, you could write a Dockerfile for your application, build an image and run it…

I’ve interviewed hundreds of candidates for various software engineering positions, and one of the most annoying situations is when you ask a concrete technical question, and the candidate starts to ramble on unrelated topics instead of just admitting “I don’t know”. Probably, this is due to a wide-spread advice that…

If you prefer to work with Kubernetes from the command line, you‘ve probably faced this problem. You’ve installed some application in a Kubernetes cluster using kubectl apply or Helm. How do you now follow what’s going on with the installation? Did the application start successfully, or did some Pod fail? …

In this article, I’ll describe how to build a runnable jar from a Kotlin application using Gradle, and try to clarify some points of confusion and errors you may face in the process. I’ll describe both Groovy and Kotlin ways of configuring the build scripts. Initial setup It’s pretty easy to generate…

A secret to writing good tests is keeping in mind that there are only two reasons for a test to exist: 1. Making sure your code works as expected. 2. Avoiding regression bugs. That’s it. There are no other reasons for a test to exist. …

As a follow-up to my previous article about CentOS 8 issues, I’d like to show how to fix a similar issue with a new CentOS 8 installation, namely, “Error setting up base repository”. I was setting up CentOS on a VMWare virtual machine, and here’s how the issue looked like: …