Containerized Development Environment

Do you spend days or weeks setting up your development environment just the way you like it when you get a new computer? Is your home directory a mess of dotfiles and metadata that you’re reluctant to clean up just in case they do something useful? Do you avoid trying new versions of software because of the effort to roll back software and settings if the new version doesn’t work?

Take control over your local development environment with containerization and Dev-Env-as-Code!

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Ansible-runner

The command ansible-runner is part of the Ansible automation platform. If you have got installed Ansible, then you probably have already installed ansible-runner as well.

But what do you use it for? Well, if you run AWX or the Ansible Automation platform package somewhere in your environment, ansible-runner is part of the magic in the background and running your code. It is also a python library that can connect your code directly to Ansible ... [continue reading]

Portable Java shell scripts with Java 21

In some rare cases you might want to run Java code as a script. Let’s discover how to create portable, executable, robust, no-compilation-needed scripts with Java 21!

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Git worktrees

Git is an important part of my daily life. Professional as well as in private I use it to manage documents and all kinds of files and changes and synchronize these between my environments.

Working alone in my repositories I can commit my changes to the branch master all day long. This works well since I am the only one working in it.

In a customer environment this is different. Different workflow might be implemented, which then require branching, merge/pull ... [continue reading]

Helidon 4 SE

Helidon 4 is a micro-service framework which purports to make our lives slightly better with speed of development coupled with speed of runtime while being light on the mind. Is it any good?

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Cilium dual-stack k3s pi-setup

This guide can be used set up a vanilla/lightweight dual-stack Kubernetes (k3s) configuration on a Raspberry Pi. You can add more k3s-nodes to achieve high-availability if needed. In the end a IPv4/IPv6 Nextcloud instance ... [continue reading]

IPv6-Only Kubernetes Clusters

As a dedicated advocate of IPv6, I recently embarked on the task of converting my personal Kubernetes cluster to an IPv6-only environment.

Why?

The growing scarcity of IPv4 addresses is a well-known issue. ... [continue reading]

In a recent project we have successfully replaced some of our usage of ActiveMQ queues with instances of Jobrunr. Lets take a look at what Jobrunr is and why it is attractive.

Using asynchronous processing is a common theme in distributed systems - maybe the client doesn’t need to know whether something was a success or some resource intensive processing takes a while to ... [continue reading]

Ansible Jinja whitespace control

Jinja is a powerful template engine for Python. Inside Ansible it is often used to dynamically create files from templates and fill in placeholders with data.

The Jinja language (now in version 2) also offers features like loops and data manipulation. Building files from loops and data-structures is more complex, especially when considering whitespace and line breaks. It can get tricky very fast.

The general approach (and I think many will agree with me on this one) ... [continue reading]

Caching OPTIONS in Varnish

Web applications may send a special HTTP method OPTIONS to query an API for functionality. If supported, the answer is a bunch of clear text HTTP headers. An OPTIONS request is usually quite lightweight for the server, but it still uses resources like connections and CPU time. The answer to an OPTIONS request seldom changes unless the API itself changes. So we have small HTTP text objects that seldom are updated. Sounds ideal for caching with Varnish.

Varnish is the ... [continue reading]