{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
  };
  outputs = { self, nixpkgs, ... }: let
    pkgs = import nixpkgs {
      overlays = [
        (import ./pkgs/overlay.nix)
      ];
      system = "x86_64-linux";
    };
    system = "x86_64-linux";
  in {
    nixosConfigurations = {
      backup-4 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/backup-4/configuration.nix
        ];
      };
      carbon = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/carbon/configuration.nix
        ];
      };
      clerie-backup = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/clerie-backup/configuration.nix
        ];
      };
      dn42-il-gw1 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/dn42-il-gw1/configuration.nix
        ];
      };
      dn42-il-gw5 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/dn42-il-gw5/configuration.nix
        ];
      };
      dn42-il-gw6 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/dn42-il-gw6/configuration.nix
        ];
      };
      dn42-ildix-clerie = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/dn42-ildix-clerie/configuration.nix
        ];
      };
      gatekeeper = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/gatekeeper/configuration.nix
        ];
      };
      hydra-1 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/hydra-1/configuration.nix
        ];
      };
      hydra-2 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/hydra-2/configuration.nix
        ];
      };
      minecraft-2 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/minecraft-2/configuration.nix
        ];
      };
      monitoring-3 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/monitoring-3/configuration.nix
        ];
      };
      nonat = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/nonat/configuration.nix
        ];
      };
      osmium = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/osmium/configuration.nix
        ];
      };
      palladium = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/palladium/configuration.nix
        ];
      };
      porter = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/porter/configuration.nix
        ];
      };
      storage-2 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/storage-2/configuration.nix
        ];
      };
      web-2 = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/web-2/configuration.nix
        ];
      };
    };

    colmena = {
      meta = {
        nixpkgs = import nixpkgs {};
      };

      defaults = { name, ... }: {
        deployment = {
          targetHost = "${name}.net.clerie.de";
          targetUser = null;
        };
      };
    } // builtins.mapAttrs (name: host: {
      nixpkgs.system = host.config.nixpkgs.system;
      imports = host._module.args.modules;
    }) self.nixosConfigurations;

    packages.x86_64-linux = {
      inherit (pkgs)
        anycast_healthchecker
        flask-excel
        iot-data
        pyexcel-xlsx
        pyexcel-webio
        uptimestatus
        wetter;
    };

    hydraJobs = {
      inherit (self)
        packages;
      nixosConfigurations = builtins.mapAttrs (name: host: host.config.system.build.toplevel) self.nixosConfigurations;
    };
  };
}