flake.nix

{
  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
  inputs.disko.url = "github:nix-community/disko";
  inputs.disko.inputs.nixpkgs.follows = "nixpkgs";
  inputs.nixos-facter-modules.url = "github:numtide/nixos-facter-modules";

  outputs =
    {
      nixpkgs,
      disko,
      nixos-facter-modules,
      ...
    }:
    {
      nixosConfigurations.hetzner-cloud = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          disko.nixosModules.disko
          ./configuration.nix
        ];
      };
      # tested with 2GB/2CPU droplet, 1GB droplets do not have enough RAM for kexec
      nixosConfigurations.digitalocean = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          disko.nixosModules.disko
          { disko.devices.disk.disk1.device = "/dev/vda"; }
          {
            # do not use DHCP, as DigitalOcean provisions IPs using cloud-init
            networking.useDHCP = nixpkgs.lib.mkForce false;

            services.cloud-init = {
              enable = true;
              network.enable = true;

              # not strictly needed, just for good measure
              datasource_list = [ "DigitalOcean" ];
              datasource.DigitalOcean = { };
            };
          }
          ./configuration.nix
        ];
      };
      nixosConfigurations.hetzner-cloud-aarch64 = nixpkgs.lib.nixosSystem {
        system = "aarch64-linux";
        modules = [
          disko.nixosModules.disko
          ./configuration.nix
        ];
      };

      # Use this for all other targets
      # nixos-anywhere --flake .#generic-nixos-facter --generate-hardware-config nixos-generate-config ./hardware-configuration.nix <hostname>
      nixosConfigurations.generic = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          disko.nixosModules.disko
          ./configuration.nix
          ./hardware-configuration.nix
        ];
      };

      # Slightly experimental: Like generic, but with nixos-facter (https://github.com/numtide/nixos-facter)
      # nixos-anywhere --flake .#generic-nixos-facter --generate-hardware-config nixos-facter facter.json <hostname>
      nixosConfigurations.generic-nixos-facter = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          disko.nixosModules.disko
          ./configuration.nix
          nixos-facter-modules.nixosModules.facter
          {
            config.facter.reportPath =
              if builtins.pathExists ./facter.json then
                ./facter.json
              else
                throw "Have you forgotten to run nixos-anywhere with `--generate-hardware-config nixos-facter ./facter.json`?";
          }
        ];
      };
    };
}