Converts Raspberry Pi OS image to a Podman container.

Input can be any 64 bit Raspberry Pi OS. Tested with bullseye. The converted image may not exceed 4GB (feel free to enlarge the value in the script if you need more). This shouldn't be a problem since you most likely want to use lite variant anyway.

Debian/Ubuntu requirements:

sudo apt install qemu-user-static qemu-system-arm xz-utils podman

First, obtain Raspberry Pi OS (64-bit) Lite from raspberrypi.com.

Then run conversion. The first argument is the path to the .xz image, second argument is the Podman image name to be created.

sudo ./convert_rpi_to_podman ~/Downloads/2023-05-03-raspios-bullseye-arm64-lite.img.xz raspi64

Please note that this imports the container to your own Podman storage. It detects the user you are running sudo with and places the resulting image there.

The conversion takes minutes. Due to Raspberry Pi OS initialization oddities, we must run it initially with full system emulation to keep the file system resize scripts happy.

During conversion, a static user emulator binary is placed in the container root filesystem and is automatically used. See QemuUserEmulation for technical details.

To run a throwaway container:

podman run --rm=true -it raspi64

To create a container with your hostname of choice and a shared directory:

podman create -it --hostname=vadelma --name=vadelma -v /path/to/share:/mnt/share raspi64

To start it, just run podman start -a vadelma.

On first run new user is prompted. After user creation, auto login happens. If that's not what you want, you may revert it by running inside the container:

systemctl revert console-getty
rm /etc/console-getty

The containerized system is manipulated carefully so that the systemd overrides are activated only when the system is running inside Podman. So, converting container back to SD card image should be possible.

Just create a smaller VFAT partition for /boot and rest as ext4 partition, copy files accordingly and adjust /etc/fstab. It should work! In case you create a tool, I'm happy to merge it.

QEMU user emulation doesn't emulate system calls but pass them to the host, so don't expect everything to work like in a native system. However, running on x86_64 syscalls are mostly compatible.

AppArmor is stupid enough to enforce rules in a different mount namespace, too. QEMU user emulation requires read access to the binary itself to be able to emulate it. Reading the binary is prohibited by some profiles such as man.

Follow system journal to see if there are AppArmor errors in the log. If so, disable (or improve) those rules.

To get man pages working, you can disable the whole rule. On the host system:

sudo ln -s /etc/apparmor.d/usr.bin.man /etc/apparmor.d/disable/

Written by Joel Lehtonen / Zouppen. Licenced under the terms of MIT license.