Not-OS – NixOS-based OS generator that outputs an OS with 47MB squashfs (2022)

https://github.com/cleverca22/not-os

by peter_d_sherman • 3 years ago

140 30 3 years ago

github.com

peoplearepeople• 3 years ago

An operating system generator, based on NixOS, that, given a config, outputs a small (47 MB), read-only squashfs for a runit-based operating system, with support for iPXE and signed boot.
runit is a cross-platform Unix init scheme with service supervision, a replacement for sysvinit, and other init schemes.

pxc4• 3 years ago

This is actually a really long-standing project by now! Michael has been a Nixer for a long time. He's very helpful and quite an adept Nix hacker. When I was first getting started with NixOS he gave me a lot of help in IRC for some packaging issues (Nixpkgs was less than 25% of it's current size back then, IIRC!) and inspired me to knuckle down and learn the Nixpkgs codebase by reading it.

Cool to see his work show up here. :)

Fans of slimmer and systemd-less spinoffs of NixOS should perhaps also check out NixNG: https://github.com/nix-community/NixNG

trynewideas• 3 years ago

Fans of slimmer and systemd-less spinoffs of NixOS should perhaps also check out NixNG

So a primary difference from NixNG is that not-OS has a kernel and initial RAM disk, making it viable for running on hardware? The sparse README says it's for "embedded" purposes, but I'm struggling to understand the value of Nix here if the whole filesystem is read-only — you'd be working entirely off the RAM disk?

vlovich123• 3 years ago

The Linux boot image is a squashfs image loaded into memory by your boot loader (eg grub). It can still mount other filesystems for on-disk partitions (provided the relevant file system and drivers are compiled into the kernel). 50MiB is a bit on the heavy side for many embedded use cases (ie M0 devices). It’s possible M3/M4 CPUs have enough storage and RAM to support this. It’s been a while since I checked the specs for those chips.

nine_k2• 3 years ago

In an embedded system you likely have all the code on a read-only filesystem which is the device's flash storage. You can have a separate device for writable storage (an SD card, another piece of flash, etc), or operate on a RAM disk entirely if all you need is storing runtime-only data. The latter is how OpenWRT operates, for instance.

touisteur• 3 years ago

Wondering now whether it'd be a good fit for microvms too.

rendaw• 3 years ago

With a read only filesystem the value is in the simple and robust tooling for assembling the image, rather than administration of the live system.

Other embedded filesystem image generation I'm aware of (like android?) require a huge swath of software and dependencies installed, byzantine build systems, star alignment, etc. Or emulation and shell scripts with timing issues, limited failure recovery/idempotency.

MuffinFlavored• 3 years ago

A lighter and simpler design, due to the omission of systemd

What does it use in alternative?

fuzzybear3965• 3 years ago

IIRC, Magic was trying to get runit working. But, the idea would be that the init system is modular/swappable.

The answers are in the source, though.

ncr100• 3 years ago

Q: What is an example usage? What have people used read-only *NIX installations for? Would this be especially suitable to run virtually?

The author has game related repos on GH and I speculate a usage they are considering is to setup an emulation station.

nine_k2• 3 years ago

Would be perfect for a small VM, or a container. Writable storage can be mounted separately where needed.

Jhsto• 3 years ago

A slight optimization here could be to use in-kernel dhcp for init1 netbooting instead of packaging dhcpd and then sleeping for 5 seconds during the bootup to get a lease -- last time I tried it the in-kernel version ensures a lease is acquired before the init script is run.

superkuh3• 3 years ago

This is the kind of NixOS project that makes sense; unlike all the people cargo culting it as a desktop OS.

avgcorrection• 3 years ago

It is an OS. Do you know what “cargo cult” means?

superkuh3• 3 years ago

It's when people begin ineffectually mimicking the surface patterns of technology necessary for one context in a completely inapropriate one in order to try to reap the benefits of it. Like using an OS designed for "deployals" necessary in some businesses/institutional contexts when you're actually just a single person running a home desktop computer.

NixOS as a desktop and hoping this reduces your complexity is the technological equivalent to making planes out of straw and hoping for cargo drops.

tripdout• 3 years ago

It works perfectly fine (even better, I'd say, than other Linux distributions) as a desktop OS. Currently running it on both a laptop and a desktop, and not sure what you're referring to.

jbverschoor• 3 years ago

Very tempting to start using a combination of nix and qubes

flurie• 3 years ago

You may be interested in Spectrum OS[1], which is more or less what you're looking for.

[1] https://spectrum-os.org/

LanternLight832• 3 years ago

Glad to see it doesn't stick with Xen, that's really interesting! (if not seL4-interesting)

LanternLight832• 3 years ago

I've had the same though with Guix, and have considered attempting to repackage / port the Qubes components, but it's one of those far fetched ideas that I know I can't make time for (or even maintain if it was just magically done).

mike_hock• 3 years ago

A kernel, initrd, and 47MB squashfs, making the squashfs the smallest of the three.

alchemist1e9• 3 years ago

Could this potentially also be used as a foundation to create an OCI compliant container image?

Slurm now supports OCI images and creating them completely from nixpkgs in an automated system would pair very well.

indigodaddy• 3 years ago

If I add any stuffs within the system, does it persist (or if not how can I make it so)

Not-OS – NixOS-based OS generator that outputs an OS with 47MB squashfs (2022)

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