Show HN: Docker-boot – Run a system from RAM without LiveCD

27 points

2 years ago

How often do you screw up the system so much you have to reformat the disk (without losing data) to fix it? Well, sometimes I do, and sometimes I can't be bothered to burn a live ISO onto a USB stick. There's initramfs, but it's hardly a pleasant environment, with network configuration and all.

My go-to solution has typically been to create a chroot with busybox and a few utilities in /tmp, chroot into it, and then kill services that use the solid drive so that I can unmount it. That's an error-prone process, and sometimes systemd itself uses disk, so you can't unmount the drive despite killing all the userland but PID 1.

This script improves the UX. It uses a Docker image as the chroot base, which is much easier to tailor to your needs, and automagically commits all the atrocities, such as tearing down all the userland processes, including PID 1, and re-spawning the host system from the container filesystem.

It also drives libostree and Nix users mad, because it can be used to try out a new DE or even a whole OS without polluting the host filesystem or spawning a virtual machine. The video in the README shows me trying out KDE + SDDM from a host running GNOME + GDM3.

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