This repository contains nix recipes of NixOS images that can be run on any GNU/Linux that has systemd using machinectl.

You don't need nix or NixOS to fetch and run the image:

# x86_64-linux architecture
machinectl pull-tar https://github.com/tfc/nspawn-nixos/releases/download/v1.0/nixos-system-x86_64-linux.tar.xz nixos --verify=no

# aarch64-linux architecture
machinectl pull-tar https://github.com/tfc/nspawn-nixos/releases/download/v1.0/nixos-system-aarch64-linux.tar.xz nixos --verify=no

machinectl start nixos
# Set root password
machinectl shell nixos /usr/bin/env passwd
machinectl login nixos

You can also change the configuration in this repository first, and then import a local build:

machinectl import-tar $(nix build --print-out-paths)/tarball/* nixos

If you want the container to use the host's network, create a configuration file like this:

printf "[Network]\nVirtualEthernet=no" > /etc/systemd/nspawn/nixos.nspawn

The system configuration in /etc/nixos/configuration.nix can be adapted to your needs. nixos-rebuild switch activates a new configuration.

If you would like to share mounts between host and container, create port mappings, etc. please refer to the systemd.nspawn config file documentation and/or the archlinux wiki about systemd-nspawn

Docker puts the file system of any Linux distro around a single process, but it essentially does not run a whole system. Running NixOS (or any other distro) in systemd-nspawn is similar to running a full VM, but with the same thin namespace isolation as in Docker, which leads to less overhead.

Changes that you do to your nspawn container remain persistent by default.