Move common aspi and kardorf nixos-config to modules

modules/nixos/builder/default.nix

@@ -0,0 +1,55 @@
+{
+  # Snowfall Lib provides a customized `lib` instance with access to your flake's library
+  # as well as the libraries available from your flake's inputs.
+  lib,
+  # An instance of `pkgs` with your overlays and packages applied is also available.
+  pkgs,
+  # You also have access to your flake's inputs.
+  inputs,
+
+  # Additional metadata is provided by Snowfall Lib.
+  namespace, # The namespace used for your flake, defaulting to "internal" if not set.
+  system, # The system architecture for this host (eg. `x86_64-linux`).
+  target, # The Snowfall Lib target for this system (eg. `x86_64-iso`).
+  format, # A normalized name for the system target (eg. `iso`).
+  virtual, # A boolean to determine whether this system is a virtual target using nixos-generators.
+  systems, # An attribute map of your defined hosts.
+
+  # All other arguments come from the module system.
+  config,
+  ...
+}:
+
+let
+  cfg = config.modules.builder;
+in
+{
+  options.modules.builder = {
+    enable = lib.mkOption { default = false; };
+  };
+
+  config = lib.mkIf cfg.enable {
+    nix.buildMachines = [
+      {
+        hostName = "192.168.3.118";
+        system = "x86_64-linux";
+        protocol = "ssh";
+        # if the builder supports building for multiple architectures,
+        # replace the previous line by, e.g.
+        # systems = ["x86_64-linux" "aarch64-linux"];
+        maxJobs = 4;
+        speedFactor = 3;
+        supportedFeatures = [
+          "nixos-test"
+          "benchmark"
+          "big-parallel"
+          "kvm"
+        ];
+        mandatoryFeatures = [ ];
+      }
+    ];
+    nix.distributedBuilds = true;
+    # optional, useful when the builder has a faster internet connection than yours
+    nix.extraOptions = "  builders-use-substitutes = true\n";
+  };
+}