Show HN: Smol machines – subsecond coldstart, portable virtual machines (github.com)

Hello, I'm building a replacement for docker containers with a virtual machine with the ergonomics of containers + subsecond start times.

I worked in AWS previously in the container space + with firecracker. I realized the container is an unnecessary layer that slowed things down + firecracker was a technology designed for AWS org structure + usecase.

So I ended up building a hybrid taking the best of containers with the best of firecracker.

Let me know your thoughts, thanks!

The feature that lets you create self-contained binaries seems like a potentially simpler way to package JVM apps than GraalVM Native.

Probably a lot of other neat usecases for this, too

  smolvm pack create --image python:3.12-alpine -o ./python312
  ./python312 run -- python3 --version
  # Python 3.12.x — isolated, no pyenv/venv/conda needed

Can .smolmachine be digitally signed and self authenticate when run? Similar to https://docs.sylabs.io/guides/main/user-guide/signNverify.ht...

I see the alpine and python:3.12-alpine images in your cli docs. Where does these come from?is it from a docker like registry or are these built in? Can I create my own images? Or this this purely done with the smolfile? Is there a Ubuntu image available?

Looks really nice btw. Hot resize mem/cpu would be nice. This could become a nice tech for a one-backend-per-customer infra orchestrator then.

Great job with the comparison table. Immediately I was like “neat sounds like firecracker” then saw your table to see where it was similar and different. Easy!

Nice job! This looks really cool

What are you actually doing on top of libkrun? Providing really small machine images that boot quickly? If I run the smolvm run --image alpine example, what is "alpine?" Where is that image coming from? Does this have some built-in default registry of machine images it pulls from? Does it need an Internet connection that allows outbound access to wherever this registry runs? Is it one of a default set of pre-built images that comes with the software itself and is stored on my own filesystem? Where are the builds for these images? Where do these machine images end up? ~/.local/share/smolvm/?

Basically any open source project nowadays run their software stack in containers often requiring docker compose. Unfortunatley Smol machines do not support Docker inside the microvms and they also do not support nested VMs for things that use Vagrant. I think this is a big drawback.

Could it be made even faster using some of the ideas from https://github.com/zerobootdev/zeroboot ?

Is there a relation to the similarly-purposed and similarly-named https://github.com/CelestoAI/SmolVM

What I really like about containers is quickly being able to spin one up without having to specify resources (e.g. RAM limit). I hope this would let me do that also.

Hey this is pretty neat! I definitely would try using this for benchmarks and other places where I need strong isolation as Docker is just too bloated and slow, but sadly I don't think I can run this natively on my Windows laptop. I hope you extend to WSL! Good luck and congrats on launch.

We’re using smolmachines to create environments for our agents to execute code. It’s been great so far and the team is super responsive. The dev ergonomics are also great.

This project is very cool! One readme nit: "Pack a stateful virtual machine into a single file (.smolmachine) to rehydrate on any supported platform." For awhile I thought this meant that you could rehydrate a machine's memory like you can with a firecracker vm, but as far as I can tell you can't? It's stateful == disk?

smolvm is awesome. The team is highly responsive and very experienced. They clearly know what they’re doing.

I’m currently evaluating smolvm for my project, https://withcave.ai, where I’m using Incus for isolation. The initial integration results look very promising!

Why would I prefer smol machines over docker sandbox? Do you have an elevator pitch?

This looks very cool. Does the VM machinery still work if I run it in a bubblewrap? Can it talk to a GPU?

Can you pipe into one? It would be cute if I could wget in machine 1 and send that result to offline machine 2 for processing.

Sounds very similar to the various unikernel implementations floating around ? Such as Unikernel[1]

[1] https://unikraft.org

Give it a try folks. Would really love to hear all the feedbacks!

Cheers!

This is a very cool project and I'm happy to see it getting traction here. I stumbled upon it when I was looking to build something similar and surveying the state of the art...then I realized you built _exactly_ what I wanted!

Thank you, great work!

im keen to check this out. since I've moved 100% to the Mac [1] I've been keen to move away from Docker to something like Apple Containers [2] which runs each "container" as an isolated vm. So I wanna try this out, too.

[1] shameful self plug: https://gigatexal.blog/pages/i-heart-my-macbook/i-heart-my-m...

[2] https://github.com/apple/container

Any integration with existing orchestrators? Plans to support any or building your own?

Doesn't Docker's sbx do this?

https://docs.docker.com/reference/cli/sbx/

see too[0][1] for projects of a similar* vein, incl historical account.

*yes, FreeBSD is specifically developed against Firecracker which is specifically avoided w "Smol machines", but interesting nonetheless

[0] https://github.com/NetBSDfr/smolBSD

[1] https://www.usenix.org/publications/loginonline/freebsd-fire...

I see you support Linux and MacOS hosts. Any Windows support planned?

This is very exciting. It enables a cross platform, language agnostic plugin system, especially for agents, while being safe in a VM.

Wow, this seems very useful for coding agent sandbox environments that have full browser installations and the like.

its a really innovative idea! very interested in the subsecond coldstart claim, how does it achieve that?

hi! congrats for your work that's really nice.

question: why do you report that qemu is 15sthanks a lot

Would love to have this as a Proxmox guest type

How does it compare to podman with crun-vm ?

This looks awesome. Thanks for sharing!

Congrats that looks really amazing!

https://shellbox.dev is a hosted version of something very similar

How many smolvm can you find?

I like the name ! :)

congrats on the launch binbin, this is cool!

https://github.com/earendil-works/gondolin is another project addressing a similar use-case.

See also SmolBSD -- similar idea, similar name, using NetBSD.

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