microvm.nix VS nix-snapshotter

- Generating virtual machines/installators from a configuration: https://github.com/astro/microvm.nix and https://github.com/nix-community/nixos-generators

MicroVM.nix, which creates firecracker/cloud-hypervisor/qemu/etc VMs: https://github.com/astro/microvm.nix

FWIW, the contemporary alternative to 9p is virtiofs. It is implemented as a separate service that is running aside the hypervisor. Originally out of qemu, it was rewritten in Rust as a freestanding project that can also be used with cloud-hypervisor and crosvm.

https://gitlab.com/virtio-fs/virtiofsd

On NixOS: https://github.com/astro/microvm.nix

Not super recent, but nix-snapshotter is one that I'd call awesome(but I'm also a k8s fanboi): https://github.com/pdtpartners/nix-snapshotter

https://news.ycombinator.com/item?id=37407758

Excellent info! I started head-deving a project similar to nix-snapshotter[0] and I was thinking "ok, I can probably just build CRI impl that builds a rootfs dir with nix and just shell out to bubblewrap to make a "container".

But once I went through that mental exercise I started reading code in containerd and cri-o. Wow, these are _not_ simple projects; containerd itself having a full GRPC-based service registry for driving dynamic logic via config.

One thing I was pretty disappointed about is how deeply ingrained OSI images are in the whole ecosystem. While you can replace almost all functional parts of runtime, but not really the concept of images. I think images are a poor solution to the problem they solve, and a big downside of this is a bunch of complexity in the runtimes trying to work around how images work (like remote snapshotters).

[0] https://github.com/pdtpartners/nix-snapshotter

Does anyone here have any experience using https://github.com/pdtpartners/nix-snapshotter ?

I build a lot of Docker images using Nix, and while yes it’s generally more pleasant than using Dockerfiles, the 128 layer limit is really annoying and easy to hit when you start building images with Nix. The workaround of grouping store paths makes poor use of storage and bandwidth.