Lxroot - a software virtualization tool

About Lxroot

lxroot is a lightweight and safe alternative to chroot, Docker, and other software virtualization tools.

lxroot allows a non-root user to easily and safely create a "chroot-style" virtual software environment (via Linux namespaces), and then run one or more programs inside that environment.

Requirements

Lxroot requires Linux kernel version 3.9 or later. (And preferably version 5.11 or later, see man user_namespaces for details.)
The kernel must have been compiled with unpriveleged namespace support. (See related discussion.)
Unpriveleged namespace support must also be enabled at runtime.

As of 2025 (and possibly even since 2020), most common Linux distributions by default both (a) support unpriveleged namespaces and (b) enable them by default.

Project Status

As of September 2023, Lxroot is still under intermittent development.
I seem to work on Lxroot several times per year. Typically, when I
work on Lxroot, I spend several days either adding new features or
refactoring existing features to make Lxroot easier to use.

I personally run software inside Lxroot every hour of every day, all year long.
As time passes, I am increasing the quantity and variety of programs that I run inside of Lxroot.

To the best of my knowledge, I am the only person who uses Lxroot
regularly. Therefore, I have been investing my energy in improving
Lxroot, rather than documenting the improvements and publishing
updates. Therefore, if you are interested in using Lxroot, please let
me know so that I can provide you with the updated and improved source
code.

Lxroot Worlds

As of September 2023, I now call an Lxroot-based chroot-style-environment a "world".

To manually create Apline Linux world named alpine, I could
(for example), do the following:

$  mkdir  -p  alpine/newroot    #  this directory is required.
$  tar  xzf  alpine-minirootfs.tar.gz  -C alpine/newroot
$  mkdir  alpine/home           #  this directory is optional.
$  mkdir  alpine/tmp            #  this directory is optional.
$  lxroot  alpine               #  use Lxroot to enter the world.

When Lxroot runs, the following directories will be bind-mounted into
alpine/newroot:

source           target
alpine/home  ->  alpine/newroot/home
alpine/tmp   ->  alpine/newroot/tmp

Then Lxroot will chroot into alpine/newroot.

Any of newroot, home, and tmp can be symbolic links. This
allows directories to be shared across multiple worlds. (Lxroot can
bind-mount any subdirectory into newroot, not just the two examples shown above.)

On a Linux kernel version 5.11 and later,
Lxroot can also create and chroot into a kernel-level overlay
filesystem. An Lxroot-world can simultaneously use both an overlay filesystem
and one or more bind-mounted subdirectories.

I have written custom scripts that create Lxroot-worlds based on
various Linux distributions. The below table summaries the types of
Lxroot-worlds that I regularly create and/or use. The distros are
ordered from most commonly used (by me) to least commonly used.

Base distro	Create world with	Install binary packages with	Can build packages?
Debian, Ubuntu, Mint	`mk-deb.sh`	`fakeroot` and `apt`	Probably?
Alpine	`mk-alpine.sh` (1)	`apk`	Probably?
Flatpak	`mk-alpine.sh` (1)	`flatpak`	Probably?
Arch	`mk-arch.sh` (1)	`pacman`	Probably?
Arch AUR	`mk-arch.sh` (1)	(n/a)	Probably?
Void	Create by hand? (2)	`xbps-install`? (2)	Probably?

Notes: (1) I have not yet published mk-alpine.sh and mk-arch.sh. (2) It has been a long time since I used Void Linux inside Lxroot, but there is a good chance that XBPS will "just work" inside Lxroot.

(Aside: Previously, I used a separate tool called vland to create and
work with Lxroot environments. However, vland is now obsolete and
unsupported. vland's functionality was either (a) moved into Lxroot
itself, or (b) moved into smaller, stand-alone scripts.)