Everything related to software development.
In this article I explain how (and why) you install and use a Linux-based self-hosted GitLab CI/CD runner that executes jobs of your GitLab pipelines. I go into a few caveats and how you can reduce maintenance efforts for the runner to a minimum. Introduction GitLab CI/CD has a distributed architecture that consists of a … Read more
In this book recommendation, I review the book Clean Code by Robert C. Martin, released in 2008. I offer my 13 page summary of the book as free download, and provide links to further reading material. Introduction to clean code In 2008, Robert C. Martin (a.k.a. “Uncle Bob”) released the book Clean code. It was … Read more
This article explains how to achieve Continuous Deployment of Docker-based software, using either pull-based approaches (external tools such as watchtower and harbormaster), or push-based techniques (deployment from the CI/CD pipeline). I explain the advantages and disadvantages of each approach, and also illustrate how automated testing greatly reduces the risk of unnoticed failed deployments. Introduction When … Read more
This article presents useful tips for operating Docker engine on a Linux server. I explain how you can improve the server’s security via automatic updates and scanning the images of your running containers, how to reduce the maintenance efforts by making sure your disks don’t run out of space, and how to set up a … Read more
This article demonstrates how to use the ArgoCD GitOps controller to deploy applications to a Kubernetes cluster. The definitions/manifests of these applications, such as an Ingress controller, monitoring stack, etc., are stored in GitLab. They are automatically updated by Renovate Bot, which regularly scans your GitLab project for outdated dependencies. A demo project illustrates how … Read more
This article provides a detailed introduction to the general concepts of GitLab CI/CD pipelines. It discusses the anatomy of the pipeline definition file, how GitLab distributes and runs jobs on runners, and what good practices you can follow. I also explain how the containerization of CI jobs affects their ability to build Docker/OCI images. Introduction … Read more
In this Logging with Loki deep dive, I explain how log collection and analysis works in principle, and then demonstrate what separates Loki from other log storage solutions. I elaborate on the different Helm charts you can use to install Loki into your Kubernetes cluster and go into the installation process using the loki-stack chart … Read more
This article discusses the different options you have to install Prometheus in Kubernetes, and then explains the installation of the Prometheus operator in detail, using the kube-prometheus-stack Helm chart. I conclude with how to upgrade your Prometheus stack as well as your own alerting rules and Grafana dashboards. Introduction The Prometheus stack is a popular set of … Read more
This article explains best practices for writing alerts on an abstract, tool-independent level. I go into technical alerting patterns (including RED and USE) and why it is better to start from a business angle instead. I elaborate on general alerting rule design, such as alert frequency and appropriate destinations, and give concrete tips for addressing … Read more
This is a deep dive into PromQL, the Prometheus query language. I discuss the basic data formats (instant vector and range vector), explain the different types of operators and functions, and then elaborate on how binary operators do result vector matching. I conclude with various PromQL tips and hints, and help you get started in … Read more