Kotlin OpenRewrite

Authoring an OpenRewrite recipe

I’ve been eying OpenRewrite for some time, but I haven’t had time to play with it yet. In case you never heard about OpenRewrite, OpenRewrite takes care of refactoring your codebase to newer language, framework, and paradigm versions. OpenRewrite is an open-source automated refactoring ecosystem for source code, enabling developers to effectively eliminate technical debt within their repositories. It consists of an auto-refactoring engine that runs prepackaged, open-source refac

Rust lazy_static LazyLock OnceLock

Runtime-initialized variables in Rust

Rust offers different ways to initialize compile time-initialized variables. Recently, I had to create a runtime-initialized variable: existing approaches don’t work in this case. I want to describe multiple ways to achieve it in this post. Constants The Rust language allows you to create constants. Two keywords are available: const and static. Sometimes a certain value is used many times throughout a program, and it can become inconvenient to copy it over and over. What’s more, it’

technical writing blog

Writing for Developers

I started this blog as a hobby seventeen years ago, in April 2008. At the time, I had no clue about technical writing. I’m pretty sure it was not even a thing back then: the only content aimed at developers was technical documentation. Since then, the landscape has changed a lot, to the point that companies hire for technical writer positions. I was curious to compare what I learned by doing to the structured approach of a book. I ordered the book last year when it was still being written

home assistant entity state temperature Netatmo

Getting a single value from a device's state in Home Assistant

This is the 7th post in the My journey with Home Assistant focus series. I recently acquired Netatmo smart radiator valves to manage my rooms' temperature remotely. I’m not skilled at manual tasks, but I could easily replace the old thermo-static valves. I then registered the smart ones in the Netatmo app. Finally, I integrated them in my Home Assistant via the dedicated Netatmo integration. Everything was very straightforward. I noticed that each valve not only allows remote control but al

Infrastructure-as-Code IaC Kubernetes Crossplane

Getting my feet wet with Crossplane

In the early days of IT, we manually configured servers–each one a precious snowflake, lovingly maintained and documented. But the size of the infrastructure grew and this approach couldn’t scale. Chef and Puppet popularized the idea of Infrastructure-as-Code: engineers would define the state of the machine(s) in text files, stored in Git–hence the name. A global node would read these files to create a registry. Then, a local agent on each machine would check the desired state at regular in

System Architecture System Design wait

The subtle art of waiting

Recently, while working on a workshop titled Testing Your Pull Request on Kubernetes with GKE, and GitHub Actions, I faced twice the same issue: service A needs service B, but service A starts faster than service B, and the system fails. In this post, I want to describe the context of these issues and how I solved them both with the same tool. Waiting in Kubernetes It might sound strange to wait in Kubernetes. The self-healing nature of the Kubernetes platform is one of its biggest benefits.

Rust

High-cardinality values for build flags in Rust

While working on my demo on WebAssembly and Kubernetes, I wanted to create three different binaries based on the same code: Native: compile the Rust code to regular native code as a baselineEmbed: compile to WebAssembly and use the WasmEdge runtime image as the base Docker imageRuntime: compile to WebAssembly, use a base scratch image as my base image, and set the runtime when running the code The code itself is an HTTP server that offers a single endpoint. For the sake of the demo, I wanted it

OpenTelemetry vCluster Kubernetes

Even more OpenTelemetry - Kubernetes special

I have presented my OpenTelemetry demo many times, and I still do. Each time, the audience is different. To make no two presentations the same, I always ask attendees what stack they are more interested in. I also regularly add new features for the same reason. I was a victim of the IT crisis last summer, and my company fired me, so I no longer work on Apache APISIX. They say that the Chinese ideogram for crisis contains the ideogram for opportunity. I used this opportunity to join LoftLabs. Lo