Today at Red Hat is day of learning again! I used the occasion to brush up my knowledge about web components and taking a look at PatternFly Elements. I’ve leered at that for a long time already – using “regular” PatternFly requires React, and thus all the npm, bundler, build system etc. baggage around it. In Cockpit we support writing your own plugins with a simple static .html and . ... Read More

For the last quarter I have worked in Red Hat’s Testing Farm (TFT) and “Operating System CI” (OSCI) and teams, on a temporary rotation. TFT develops and runs the Testing Farm (TF) infrastructure, an API which you tell “go run a test with $these parameters, it allocates a bunch of cloud instances, sets them up, runs your test, and returns the result. OSCI builds upon this to implement Fedora’s and RHEL’s gating tests for package updates, image builds, upgrades, and so on. ... Read More

I spent this day of learning on evaluating the three popular high-level Rust frameworks for HTTP/websocket servers. At some point we want/need to rewrite Cockpit’s web server, and Rust feels like a natural choice for this (besides Python). My goal was to write a little webserver which can do the following: /hello: simple http GET, with optional User-Agent: header inspection: curl http://localhost:3030/hello/myname replies with “Hello myname from from curl/7. ... Read More

I recently found myself needing to write a dynamic reverse HTTP/websocket proxy. After some prototyping it is now time to write something real. To prepare myself for that, I devoted today’s Red Hat Day of Learning to another aspect of Rust: asynchronous programming, and learning about tokio. There is really no getting around tokio in the Rust world of networking. I started with the small book “Asynchronous Programming in Rust”. Honestly I found this a bit hard to follow, as it quickly dives into a lot of technical details, which I don’t have yet. ... Read More

Today was another Red Hat Day of Learning. Half a year ago I started learning Rust, but have not really done much with it since then. I did try to port simple-term, but that was quickly thwarted by the unmaintained and broken vte Rust binding for GTK3 – that issue is still way over my head, I didn’t make much progress after two hours of monkey patching. I have used gtimelog to track my work for my entire professional life (since 2004). ... Read More

Cockpit CI demands Testing Cockpit is not an easy task – each pull request gets tested by over 300 browser integration test cases on a dozen operating systems. Each per-OS test suite starts hundreds of virtual machines, and many of them exercise them quite hard: provoking crashes, rebooting, attaching storage or network devices, or changing boot loader arguments. With these requirements we absolutely depend on a working /dev/kvm in the test environment, and a performant host to run all these tests in a reasonable time. ... Read More

Why Rust? I had spent the last two rainy days of my summer vacation on learning Rust. Rust is becoming ever-more popular and is even making its way into the Linux kernel – so it feels like something I should know a little about. There have been a lot of new languages in the recent years, like Kotlin or Go. None of them are particularly attractive to me personally, as their strenghts and “selling points” just don’t apply enough to what I do – so far, that has been covered rather well between C, Python, and JavaScript. ... Read More

In the Cockpit team we recently started to generate and export metrics about our CI, and collect/graph them by a Red Hat internal Prometheus and Grafana instance. But I am not happy with this yet, as it does not yet answer all the questions that we have for it. Also, it is not accessible outside of Red Hat. On today’s Red Hat Day of Learning I wanted to get to know how to deploy these components and learn more about the PromQL language. ... Read More

Email: A source of stress Email has been a significant source of stress for me. Canonical, Red Hat, Debian and free software projects all are a firehose of announcements, discussions, bug reports, review requests, questions, and work tasks every day. I am fairly good and efficient at quickly deleting the 90% irrelevant email, but the type of “10 seconds for the sender to write, half a day of work for me to act upon” emails pile up, break my motivation, and cause annoyance and refusal. ... Read More

Today is another Red Hat Day of Learning. A while ago I heard about snowpack, a new contender for the trusty old webpack to build modern web projects. Today I finally managed to take a quick look at it. Even with webpack --watch one often needs to wait several seconds up to half a minute with some larger cockpit pages, so the promised split-second builds certainly sound attractive. At first sight it also makes more opinionated choices about sensible defaults, so that one hopefully does not have to write such a wall of boilerplate. ... Read More