nix/os/devices/CFB4ED74: enable hydra

nix/os/devices/CFB4ED74/pkg.nix

@@ -12,6 +12,24 @@
     openDefaultPorts = true;
   };
 
+ services.hydra = {
+    enable = true;
+    hydraURL = "http://localhost:3000"; # externally visible URL
+    notificationSender = "hydra@${config.networking.hostName}.stefanjunker.de"; # e-mail of hydra service
+    # a standalone hydra will require you to unset the buildMachinesFiles list to avoid using a nonexistant /etc/nix/machines
+    buildMachinesFiles = [];
+    # you will probably also want, otherwise *everything* will be built from scratch
+    useSubstitutes = true;
+  };
+
+  nix.buildMachines = [
+    { hostName = "localhost";
+      system = "x86_64-linux";
+      supportedFeatures = ["kvm" "nixos-test" "big-parallel" "benchmark"];
+      maxJobs = 4;
+    }
+  ];
+
   services.gitlab-runner = {
     enable = true;