hydra: add dacbert to buildMachines

hosts/dacbert/default.nix

@@ -54,6 +54,25 @@
     firewall.enable = false;
   };
 
+  nix = {
+    buildCores = 4;
+    maxJobs = 1;
+    package = lib.mkForce pkgs.nixUnstable;
+    trustedUsers = [ "client" ];
+    extraOptions = ''
+      builders-use-substitutes = true
+    '';
+    daemonCPUSchedPolicy = "idle";
+    daemonIOSchedClass = "idle";
+  };
+  systemd.services.nix-daemon.serviceConfig = {
+    LimitNOFILE = lib.mkForce 8192;
+    CPUWeight = 5;
+    MemoryHigh = "4G";
+    MemoryMax = "6G";
+    MemorySwapMax = "0";
+  };
+
   environment.systemPackages = with pkgs; [
     libraspberrypi
     raspberrypi-eeprom

hosts/hydra/hydra.nix

@@ -25,6 +25,13 @@ in {
       ];
       supportedFeatures = [ "big-parallel" ];
       maxJobs = 4;
+    } {
+      hostName = "client@dacbert.hq.c3d2.de";
+      system = lib.concatStringsSep "," [
+        "aarch64-linux"
+      ];
+      supportedFeatures = [ "benchmark" "kvm" "nixos-test" ];
+      maxJobs = 1;
     } ];
 
     daemonCPUSchedPolicy = "idle";
@@ -32,8 +39,6 @@ in {
     daemonIOSchedPriority = 7;
   };
 
-  systemd.services.nix-daemon.serviceConfig.LimitNOFILE = lib.mkForce 8192;
-
   services.hydra-dev = {
     enable = true;
     hydraURL = "https://hydra.hq.c3d2.de";
@@ -53,6 +58,7 @@ in {
     MemorySwapMax = "16G";
   };
   systemd.services.nix-daemon.serviceConfig = {
+    LimitNOFILE = lib.mkForce 8192;
     CPUWeight = 5;
     MemoryHigh = "32G";
     MemoryMax = "32G";