sdme

Lightweight systemd-nspawn containers with overlayfs.

Quick install

Download a static binary from fiorix.github.io/sdme.

Runs on Linux with systemd. Uses kernel overlayfs for copy-on-write storage. By default, containers are overlayfs clones of / but you can also import rootfs from other distros (Ubuntu, Debian, Fedora, NixOS; see docs/nix).

Why does this even exist? Here's my pitch: from a linux system with just systemd and sdme, you can create and run any container and cloud image that exists today. 1 binary.

Check out the sdme architecture for details about what this is and how it works. The containers we create are booted systemd containers.

On macOS? See docs/macos.md for instructions using lima-vm.

Usage

Cloning your own "/" filesystem:

sudo sdme new

By default, host-rootfs containers (no -r) make /etc/systemd/system and /var/log opaque so the host's systemd overrides and log history don't leak in. Override with -o or change the default via sdme config set host_rootfs_opaque_dirs.

Importing a root filesystem on Ubuntu with debootstrap:

$ debootstrap --include=dbus,systemd noble /tmp/ubuntu
$ sudo sdme fs import ubuntu /tmp/ubuntu
$ sudo sdme new -r ubuntu

Importing filesystem from an OCI container

Fedora:

sudo sdme fs import fedora quay.io/fedora/fedora
sudo sdme new -r fedora

Debian:

sudo sdme fs import debian docker.io/debian
sudo sdme new -r debian

sdme can also run OCI application images (nginx, mysql, etc.) as systemd services inside a base container. See docs/oci.md for details.

Dependencies

Runtime

Install all dependencies (Debian/Ubuntu)

sudo apt install systemd-container

For QCOW2 image imports, also install qemu-utils.

Build

cargo build --release       # build the binary
cargo test                  # run all tests
cargo test <test_name>      # run a single test
make                        # same as cargo build --release
sudo make install           # install to /usr/local (does NOT rebuild)