To build an Arch Linux Docker image you would typically take the + mkimage-arch-pacman.conf as described on the Wiki, and run it as root on an Arch machine. This poses 2 issues: you may not have root access, and what if you want to build Arch Linux image on eg. Ubuntu? So I came up with a setup (Dockerfile, Python script, .dockerignore file) that lets you build Arch Linux Docker images on any Linux host running Docker, as a regular user (if your Docker instance allows that, but please mind there are good reasons why it shouldn't), FROM scratch, using bootstrap tarballs, which are published alongside Arch Linux ISO installation media every 4 weeks.