In my talk Evolving your APIs, I mention that an API Gateways is a Reverse Proxy 'on steroids'. One key difference between the former and the latter is that the API Gateway is not unfriendly to business logic. The poster child is rate-limiting. Rate-limiting is an age-old Reverse Proxy feature focused on protecting against DDoS attacks. It treats all clients the same and is purely technical. In this day and age, most API providers offer different subscription tiers; the higher the tier, the hig ..read more

I spoke at Swiss PgDay in Switzerland in late June. The talk was about how to create a no-code API with the famous PostgreSQL database, the related PostgREST, and Apache APISIX, of course. I already wrote about the idea in a previous post. However, I wanted to improve it, if only slightly. PostgREST offers a powerful SELECT mechanism. To list all entities with a column equal to a value, you need the following command: curl /products?id=eq.1 id is the columneq.1 corresponds to the WHERE cla ..read more

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 ..read more

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 ..read more

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 ..read more

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 ..read more

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 ..read more

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 ..read more

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 ..read more

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& ..read more