MicroVM.nix

A Nix Flake to build NixOS and run it on one of several Type-2 Hypervisors.

Warning: This is a Nix Flakes-only project. Use with nix-shell -p nixFlakes

Installation

nix registry add microvm github:astro/microvm.nix

(If you do not want to inflict this change on your system, just replace microvm with github:astro/microvm.nix in the following examples.)

Start your own NixOS MicroVM definitions

nix flake init -t microvm

Examples

Run MicroVMs on your local machine

nix run microvm#qemu-example
nix run microvm#firecracker-example
nix run microvm#cloud-hypervisor-example
nix run microvm#crosvm-example
nix run microvm#kvmtool-example

Run a Virtual Machine to host example MicroVMs on 5 different Hypervisors

nix run microvm#vm

Check networkctl status virbr0 for the DHCP leases of the MicroVMs. They listen for ssh with an empty root password.

NixOS modules

microvm.nixosModules.host

• Declarative configuration of MicroVMs with microvm.vms
• The microvm command to imperatively manage the installation

Use this on a (physical) machine that is supposed to host MicroVMs.

microvm.nixosModules.microvm

This module is automatically included in MicroVMs.

Ideas

• Boot with root off virtiofs, avoiding overhead of creating squashfs image
• Provide a writable /nix/store
• Distribute/fail-over MicroVMs at run-time within a cluster of hosts