DNS, Images, CPUs, Koyeb, Laptop, TLS

1. DNS tinkering: .local vs .localhost vs .test vs .dev vs .internal, etc. If you don't know the difference(s), you should. All of those are essentially and technically very different things (Summer 2025) even if all of those do seem like simple "I can use that" strings.

2. PNG is back with its 3rd generation (@ www.w3.org) - New PNG format with extensions. For some very niche cases that's the way to go. But for most cases WebP, AVIF and JPEG XL are way, way superior. If unsure, always use WebP (lossy or lossless both are good).

3. Helping a friend to configure network printers remotely. This is as frustrating and painful a task as it gets. Well, yeah sure. You'll get it done, but it's incredibly inefficient.

4. Long discussion with tech nerds about CPU vulnerability mitigation and performance. Well yeah, it depends; in some environments it's required and others, not. There's no correct answer.

5. Koyeb is a very nice European solution for specific "hosting" use cases. I studied it and tested their services thoroughly. It fits very nicely between low-level providers and high-level web hosting providers which I've talked so much about. As well as they've got great AI / LLM options, which can be utilized with the service(s). It's good to know that they do have an HTTP(S) only networking restriction. Yet it depends what kind of control you've got over clients, because they do support WebSockets and Server-Sent Events (SSE) over HTTPS.

6. I've read about HTTPS/SSE (Server-Sent Events) several times, but haven't ever written a test server / client. Now I did it just for fun. I've been mostly using WebSockets, but SSE is so much simpler for "push data / events from server" use cases.

7. Firecracker inside Docker... I had to test that quickly if it works, and it does! What a configuration, lol! But that can be used in case you want to further isolate some stuff or run full virtualization inside docker. Made me smile, worked well. I launched alpine inside docker which runs in Ubuntu. Check worked. I'll keep this in mind if I need it later. The trick necessary to make it work is to pass the KVM device access to the container --device /dev/kvm.

8. Laptop "fix" - Based on the initial fault description, the machine's (a laptop's) cooler was broken, and that turned out to be true. The machine would stay on for a moment and then shut down when it got too hot. What then? A closer inspection, once I got the model and other details, revealed it was a 2015 HP running Windows 10. It's not worth repairing a machine that old; depending on the options, a repair would have cost roughly €30 - €200. Regular users are the type who never have backups, so what's the solution? I connected an external drive to the machine. At first, I considered cooling it with a vacuum cleaner. However, a perfectly good hair dryer was available on-site, so we ended up using that. I aimed the hair dryer at the cooling vent, turned on the airflow, and powered on the machine... after about 15 minutes of waiting and a burn-in test. It stayed on. Nothing left but to use robocopy to copy the entire Users folders to the external drive. Selecting and ordering a new laptop is the next phase. So, the outcome was that a repair wasn't even needed.

9. About TLS problems. Another application absolutely requires that the session be continued, and refuses to function without it. And of course, the other end doesn't even know what continuing the session means. So these are just the nice normal everyday situations.

10. Something different? K239 Chunmoo (@ Wikipedia) and its variant Homar-K for Poland.

2026-07-26