Skyflake: Hyperconverged Infrastructure for NixOS

• No Docker, no Kubernetes
• Hosts run NixOS, payloads are NixOS in microvm.nix
• Static hosts, dynamic virtual machines managed by Nomad
• Deploy machines by git push your Nix Flake

Running the example cluster

• Have a bridge virbr0.

• Provide Internet access.

• Have 3x 4 GB RAM.

• Have 3x 20 GB disk.

• Put your SSH public key into example-server.nix

• Run MicroVMs in parallel:

  nix run .#example1
  nix run .#example2
  nix run .#example3
  

• Login and check for the IP address.

• Next, create your user flake:

  {
    outputs = { self, nixpkgs }: {
      nixosConfigurations =
        let
          mkHost = hostName:
            nixpkgs.lib.nixosSystem {
              modules = [ {
                system.stateVersion = "22.11";
                networking = { inherit hostName; };
                services.openssh = {
                  enable = true;
                  permitRootLogin = "yes";
                };
                users.users.root.password = "";
              } ];
              system = "x86_64-linux";
            };
        in {
          skytest1 = mkHost "skytest1";
          skytest2 = mkHost "skytest2";
          skytest3 = mkHost "skytest3";
          skytest4 = mkHost "skytest4";
        };
    };
  }
  

• Finally, deploy by pushing to a branch by hostname:

  git push [email protected]:example \
    HEAD:skytest1 HEAD:skytest2 \
    HEAD:skytest3 HEAD:skytest4
  

How it works

The central component is a nixosModule that is configured for servers to be part of a cluster.

Users have a flat hierarchy of flake repositories they can push to. Their ssh interaction is forced into a custom script that lets only git push, triggering a hook that does the following:

1. Builds the NixOS system
2. Copies the result into a cluster-shared binary cache
3. Runs the job on the cluster through Nomad

Server configuration options

The nixosModule for the servers that make up the cluster provides the following knobs:

TODO

Deployment customization

Network setup, storage integration and more options of the MicroVMs must be customized for the environment.

See default-customization.nix