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smolBSD

build your own minimal BSD UNIX system

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About

smolBSD is a meta-operating system built on top of NetBSD. It lets
you compose your own UNIX environment -- from a single-purpose
microservice system to a fully-custom OS image -- in just a few
minutes.

The smolBSD environment uses the netbsd-MICROVM kernel as its
foundation, leveraging the same portable, reliable codebase that
powers NetBSD itself. You decide what to include -- sshd, httpd, or
your own service -- and smolBSD builds a coherent, minimal, bootable
image ready to run anywhere.

$ bmake SERVICE=bozohttpd build
[?]   starting the builder microvm
[?]   host filesystem mounted on /mnt
[?]   fetching sets
[?]   creating root filesystem (512M)
done  image ready: bozohttpd-amd64.img


Why smolBSD

Build BSD systems like you build software -- fast, reproducible, and
minimal.

 Composable

Pick only the components you need -- from kernel to services.

[?][?] Reproducible

Every build is deterministic, portable, and easy to version-control.

 Instant Boot

Powered by netbsd-MICROVM -- boot to service in milliseconds.

 Universal

Runs anywhere QEMU or Firecracker runs -- cloud, CI, edge, or laptop.

Quick Start

Build and boot your own BSD system in seconds:

$ git clone https://github.com/NetBSDfr/smolBSD
$ cd smolBSD
$ bmake SERVICE=sshd build
[?]   starting the builder microvm
[?]   fetching sets
[?]   creating root filesystem (512M)
done  image ready: sshd-amd64.img
[?]   killing the builder microvm

$ ./startnb.sh -f etc/sshd.conf
[   1.0092096] kernel boot time: 14ms
Starting sshd.
Server listening on :: port 22.
Server listening on 0.0.0.0 port 22.


Download

Examples

bozohttpd

A complete static web server in a few megabytes. smolBSD builds a
minimal system with bozohttpd preconfigured and ready to serve
content immediately on boot.

$ bmake SERVICE=bozohttpd build
[?]   starting the builder microvm
[?]   fetching sets
[?]   creating root filesystem (512M)
done  image ready: bozohttpd-amd64.img

$ ./startnb.sh -f etc/bozohttpd.conf
[   1.001231] kernel boot time: 10ms
Starting bozohttpd on :80
listening on 0.0.0.0:80


nbakery

A lightweight build and image creation service based entirely on
NetBSD tools. The nbakery image gives you a taste of a preconfigured
NetBSD environment with all the well known tools.

$ bmake SERVICE=nbakery build
[?]   starting the builder microvm
[?]   fetching sets
[?]   creating root filesystem (512M)
done  image ready: nbakery-amd64.img

$ ./startnb.sh -f etc/nbakery.conf
[   1.008374] kernel boot time: 11ms

Welcome to the (n)bakery! 

 doas  to run command as root
 pkgin to manage packages
 exit to cleanly shutdown, ^a-x to exit qemu
 you are inside a tmux with prefix ^q


nitrosshd

A minimal secure shell server started with nitro, designed to launch
instantly and provide remote access with zero unnecessary services.
Ideal for an SSH bouncer.

$ bmake SERVICE=nitrosshd build
[?]   starting the builder microvm
[?]   fetching sets
[?]   creating root filesystem (512M)
done  image ready: nitrosshd-amd64.img

$ ./startnb.sh -f etc/sshd.conf
[   1.011598] kernel boot time: 12ms
Created tmpfs /dev (1835008 byte, 3552 inodes)
Starting sshd.
Server listening on :: port 22.
Server listening on 0.0.0.0 port 22.


Community

smolBSD is an independent project built on top of NetBSD. Join us,
share your micro-systems, or contribute new services and build
recipes.

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