A Java geek

Last week, I described how to add a dynamic watermark to your images on the JVM. I didn’t find any library, so I had to develop the feature, or, more precisely, an embryo of a feature, by myself. Depending on your tech stack, you must search for an existing library or roll up your sleeves. For example, Rust offers such an out-of-the-box library. Worse, this approach might be impossible to implement if you don’t have access to the source image. Another alternative is to use ready-mad

Displaying images on your website makes for an interesting problem: on one side, you want to make them publicly available; on the other, you want to protect them against undue use. The age-long method to achieve it is watermarking: A digital watermark is a kind of marker covertly embedded in a noise-tolerant signal such as audio, video or image data. It is typically used to identify ownership of the copyright of such signal. 'Watermarking' is the process of hiding digital information in a car

In my earlier post about moving from Kotlin Scripting to Python, I mentioned several reasons: Separating the content from the scriptKotlin Scripting is an unloved child of JetBrainsRenovate cannot update Kotlin Scripting files I was wrong on the third point. Here’s my mea culpa. First things first, Renovate does indeed manages Kotlin Scripting files - since 2022. Even better, Renovate can manage any type of file. Thanks to Max Andersen for the tip: JVM's are cheap; not having to

I moved my blog from WordPress to GitLab Pages in…​ 2016. I’m happy with the solution. However, I used GitHub Pages when I was teaching for both the courses and the exercises, e.g., Java EE. At the time, there was no GitHub Actions: I used Travis CI to build and deploy. Recently, I had to use GitHub Pages to publish my Apache APISIX workshop. Travis is no longer free. GitHub Actions are a thing. I used the now nominal path and faced a few hurdles; here are my findings. GitHu

My ideas for blog posts inevitably start to dry up after over two years at Apache APISIX. Hence, I did some triage on the APISIX repo. I stumbled upon this one question: We have a requirement to use a plugin, where we need to route the traffic on percentage basis. I’ll give an example for better understanding. We have an URL https://xyz.com/ca/fr/index.html where ca is country (canada) and fr is french language. Now the traffic needs to routed 10% to https://xyz.com/ca/en/index.html a

I continue to work on my Opentelemetry demo. Its main idea is to showcase traces across various technology stacks, including asynchronous communication via an MQTT queue. This week, I added a couple of components and changed the architecture. Here are some noteworthy learnings; note that some of them might not be entirely connected to OpenTelemetry. Here’s an updated diagram. New components appear in violet, and updated components appear in green. I want to be able to add more comp

I’m in the process of adding more components to my OpenTelemetry demo (again!). The new design deploys several warehouse services behind the inventory service so the latter can query the former for data via their respective HTTP interface. I implemented each warehouse on top of a different technology stack. This way, I can show OpenTelemetry traces across several stacks. Anyone should be able to add a warehouse in their favorite tech stack if it returns the correct JSON payload to the inv

A (long) time ago, my first job consisted of implementing workflows using the Staffware engine. In short, a workflow comprises tasks; an automated task delegates to code, while a manual task requires somebody to do something and mark it as done. Then, it proceeds to the next task - or tasks. Here’s a sample workflow: The above diagram uses Business Process Model and Notation. You can now design your workflow using BPMN and run it with compatible workflow engines. Time has passed. Sta

I’ve always liked GUI, both desktop-based and browser-based before you needed five years of training on the latter. That’s the reason I loved, and still love Vaadin: you can develop web UIs without writing a single line of HTML, JavaScript, and CSS. I’m still interested in the subject; a couple of years ago, I analyzed the state of JVM desktop frameworks. I also like the Rust programming language a lot. Tauri is a Rust-based framework for building desktop applications. Here&