Wrapper for machinectl and systemctl to manage systemd-nspawn OS containers with a prescriptive way to cutover to new images and fallback to old ones (without depending on BTRFS or ZFS). OverlayFS is used to maintain control over changes from the original image. The goal of this wrapper is to remain as light-weight as possible, preferencing the preservation of the systemd-nspawn-flavored approaches to running containers over any features added in this wrapper script. This is not intended to replace machinectl, but to instead to supplement it with a prescriptive workflow for upgrading to new system containers while providing a valid fallback posture if needed. Note: this is a work in progress, so it is not stable yet.