Multistrap

Multistrap is a tool used to bootstrap Debian-based root filesystems. It is designed to ease the creation of custom Debian or Ubuntu roots for embedded systems, containers, or chroots by assembling a filesystem from packages managed by the system’s package manager.

Multistrap operates by reading a configuration file (commonly multistrap.conf) that describes one or more bootstrap targets. Each target specifies fields such as architecture, repositories, components, and a list of packages to install, with optional pre- and post-install scripts that run inside the resulting root. When run, multistrap populates a designated directory with a minimal Debian/Ubuntu system based on the configuration.

Key features include support for bootstrapping multiple architectures and multiple roots in a single invocation, customization of apt sources, and hooks or scripts to tailor the build process. The output is a ready-to-use root filesystem suitable for chroot environments, containers, or image creation for embedded deployments.

In practice, multistrap is used in Debian-derived environments to generate reproducible, customized root filesystems without assembling a full live image. It complements other tools such as debootstrap by providing a higher-level configuration approach for multi-root or multi-arch builds. Its use spans embedded development, testing, and scenarios requiring controlled, repeatable filesystem images.

The maintenance status of multistrap has varied across Debian releases. Users often consider debootstrap directly or alternative image-building tools depending on their needs and the level of maintenance and ecosystem support desired. See also debootstrap, apt, root filesystem, embedded Linux, container.