major refactor

mod/build-machines.nix

@@ -0,0 +1,30 @@
+{ lib, config, ... }:
+with lib;
+{
+  options.hd.buildMachines.enable = mkEnableOption "Use standard remote builders";
+  config = mkIf config.hd.buildMachines.enable {
+    nix = {
+      buildMachines = [
+        {
+          hostName = "noravm"; # TODO: do not rely on mutable ssh config
+          sshUser = "nixremote";
+          system = "x86_64-linux";
+          protocol = "ssh-ng";
+          maxJobs = 32;
+          speedFactor = 2;
+          supportedFeatures = [
+            "nixos-test"
+            "benchmark"
+            "big-parallel"
+            "kvm"
+          ];
+          mandatoryFeatures = [ ];
+        }
+      ];
+      distributedBuilds = true;
+      extraOptions = ''
+        	  builders-use-substitutes = true
+        	'';
+    };
+  };
+}