Nick's TechBlog

Miscellaneous December 2020

How to Create and Use Custom CAs with OpenSSL

Sometimes I need to create certificates for testing purposes. For example, I set up an etcd cluster by hand recently. This happens rarely enough that I need to look up the openssl syntax every time.

Linux November 2020

Implementing a Linux Syscall

Sometimes, issues can only be fixed in a layer below the abstractions you rely on usually. Understanding the whole stack as much as possible is a great advantage when a bug pops up. For this reason, I decided to implement a simple Linux syscall to become familiar with the Linux

DevOps November 2020

Migrating my Blog to Docker

When I started this blog at the end of 2018, I didn't want to spend much time on the blog's setup, but rather get started writing as soon as possible. For this reason, I chose a preconfigured VM image with the blogging software Ghost that was offered by my cloud

Event November 2020

Hacktoberfest 2020

Another year, another Hacktoberfest. Hacktoberfest is an event meant to promote open source involvement. This year, I created a basic ray tracer and also contributed to a Prometheus exporter. Ray tracerMy ray tracer is implemented in Golang without any dependencies and is heavily inspired by the C++ code from the

Security August 2020

DNS Amplification Attacks

I received an interesting E-Mail from my ISP recently. It said (translated from german): "Security warning: we detected an open DNS resolver on your system. Open DNS resolvers can be misused for DDoS reflection attacks against third parties." I was indeed running a publicly exposed DNS server that acted as

Kubernetes January 2020

Notes on "Kubernetes The Hard Way" with LXC

This blog post documents the steps I took to create a Kubernetes cluster according to Kelsey Hightower's "Kubernets The Hard Way", but with LXC.

DevOps January 2020

An Introduction to Canary Deployments

This blog post briefly explains canary deployments. The content doesn't assume the use of specific technologies, although the examples reference Kubernetes concepts.

book January 2020

Book review: "The Unicorn Project"

"The Unicorn Project" by Gene Kim is the successor to the book "The Phoenix Project", although the books can be read independently.

Security November 2019

Secret Management with HashiCorp Vault

HashiCorp Vault is a tool for centralized secrets management. In my opinion, the best way to learn a technology is to use it. For this reason, we are going to build a demo system in this blog post.

Event November 2019

Hacktoberfest 2019

Every year, Digital Ocean organizes Hacktoberfest, an event meant to promote Open Source involvement. Everyone who registers and creates 4 Pull Requests in October on GitHub receives a T-Shirt.

SPA October 2019

Serving Single Page Applications

Gain a high level understanding of the infrastructure pieces and traffic routing rules that are involved when a SPA frontend is used

Miscellaneous September 2019

On Great Commit Messages

As a software engineer, attention to detail is key because one small typo in your code can cause catastrophic bugs. Code isn't the only artefact software engineers produce, though. For example, most of us create numerous commits every day.

Logging September 2019

Centralized Logging on Kubernetes with Fluentd, Elasticsearch and Kibana

Centralized logging refers to collecting logs of many systems across multiple hosts in one central logging system. With the logs in a common log system, debugging issues with distributed systems becomes a lot easier because the logs can be analyzed efficiently.

Prometheus January 2019

Managing Prometheus on Kubernetes with Prometheus Operator

Kubernetes and Prometheus are a popular combination. CoreOS created a Kubernetes Operator which streamlines operating and configuring Prometheus in Kubernetes. This post is an introduction to Prometheus Operator.

Prometheus December 2018

Monitoring Batch Jobs with Prometheus

This article will describe how to monitor batch jobs with Prometheus. The defining characteristic of batch jobs is their limited lifetime. Monitoring ephemeral jobs with Prometheus is suboptimal due to Prometheus pull-based architecture.