firewalld and common equivalents in iptables
As I increasingly use distributions that rely on firewalld over the old ways of manually configuring iptables this article notes down some common patterns encountered.
Transcoding a HDR video with tonemapping
Before HDR came into wider use, working with video was easier. You didn't have to care about colorspaces [1], it would display fine everywhere and working with it was painless. With HDR it's not so simple anymore: To display it a process called tonemapping needs to be applied and you even need a HDR-capable output device in order to see a meaningful difference compared to SDR (Standard Dynamic Range).
Here I will document how you can convert HDR video to SDR, e.g. to view it on an older device.
How to trick Windows 10 to install on an USB drive
Suppose you want a Windows installation for your computer, but a bit more portable. You might think to use an external USB but the truth is Microsoft doesn't want you doing this and prevents it in the Windows installer.
Linux package managers cheatsheet
This post isn't for the basic operations like installing stuff, because those are easy to remember or easy to figure out if you're missing them.
Putting a systemd service behind a VPN
It recently occurred that I had the need to route all traffic by a certain application through a VPN. While premade solutions for this exist using Docker (especially in combination with BitTorrent clients), I preferred looking for something that really just isolates what is needed and leaves the rest alone.
Ad-hoc router using OpenWrt in a VM
OpenWrt build notes
This post contains Q&A-style notes on compiling software for OpenWrt or compiling OpenWrt itself.
Headless Raspberry Pi OS virtualization, 64-bit edition
With Raspbian (now named Raspberry Pi OS) having been released as 64-bit, I can finally write a proper sequel to the previous post that dealt with virtualizing ARM/Linux distributions headlessly using QEMU.
You can read the original article here: Virtualizing Raspbian (or any ARM/Linux distro) headless using QEMU. Since the process is the same I will skip detailed explanations here.
Installing UniFi Network on Raspberry Pi OS 11 (bullseye)
Installing an Unifi controller on a Raspberry Pi seems like a straightforward task until you notice the section with system requirements.
The software requires a MongoDB version before 4.0. The last version that satisfies this is 3.7.9 which is almost four years old at the time of writing. You may find old versions packaged on the MongoDB website or in other repositories but certainly not for ARM. The second problem is that MongoDB dropped 32-bit support in version 3.4 so the latest we can actually use is 3.2.22 (also 4 years old).
In the end I was unable to find a build of MongoDB 3.2 that could run on a Pi which leaves only the option of compiling from source. This is what I ended up doing, it required lots of trial and error [1] before it succeeded. To (hopefully) save someone else time I put up the final Debian package for download.
Overview of VPN providers that support IPv6
Finding commercial VPN providers that provide actual real IPv6 support
(and not just "leak protection" aka a blackhole route) is pretty hard so
I decided to write down the ones I know about.
The amount of information present depends on the provider's documentation and whether I have tested them myself.