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.

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, with optional cross-container access via connectors. 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)