diff --git a/Deployments/hydra.nix b/Deployments/hydra.nix
new file mode 100644
index 0000000..e163f67
--- /dev/null
+++ b/Deployments/hydra.nix
@@ -0,0 +1,89 @@
+# NixOps configuration for the VMs running Hydra
+
+{ config, pkgs, lib, ... }:
+
+{
+
+  services.postfix = {
+    enable = true;
+    setSendmail = true;
+  };
+
+  services.postgresql = {
+    enable = true;
+    package = pkgs.postgresql;
+    identMap =
+      ''
+        hydra-users hydra hydra
+        hydra-users hydra-queue-runner hydra
+        hydra-users hydra-www hydra
+        hydra-users root postgres
+        hydra-users postgres postgres
+      '';
+  };
+
+  networking.firewall.allowedTCPPorts = [ config.services.hydra.port ];
+
+  services.hydra = {
+    enable = true;
+    useSubstitutes = true;
+    hydraURL = "https://hydra.mcwhirter.io";
+    notificationSender = "hydra.mcwhirter.io";
+    buildMachinesFiles = [];
+    extraConfig = ''
+      store_uri = file:///var/lib/hydra/cache?secret-key=/etc/nix/hydra.mcwhirter.io/secret
+      binary_cache_secret_key_file = /etc/nix/hydra.mcwhirter.io/secret
+      binary_cache_dir = /var/lib/hydra/cache
+    '';
+  };
+
+  services.nginx = {
+    enable = true;
+    recommendedProxySettings = true;
+    virtualHosts."hydra.mcwhirter.io" = {
+      forceSSL = true;
+      enableACME = true;
+      locations."/".proxyPass = "http://localhost:3000";
+    };
+  };
+
+  security.acme.certs = {
+      "hydra.mcwhirter.io".email = "craige@mcwhirter.io";
+  };
+
+  systemd.services.hydra-manual-setup = {
+    description = "Create Admin User for Hydra";
+    serviceConfig.Type = "oneshot";
+    serviceConfig.RemainAfterExit = true;
+    wantedBy = [ "multi-user.target" ];
+    requires = [ "hydra-init.service" ];
+    after = [ "hydra-init.service" ];
+    environment = builtins.removeAttrs (config.systemd.services.hydra-init.environment) ["PATH"];
+    script = ''
+      if [ ! -e ~hydra/.setup-is-complete ]; then
+        # create signing keys
+        /run/current-system/sw/bin/install -d -m 551 /etc/nix/hydra.mcwhirter.io
+        /run/current-system/sw/bin/nix-store --generate-binary-cache-key hydra.mcwhirter.io /etc/nix/hydra.mcwhirter.io/secret /etc/nix/hydra.mcwhirter.io/public
+        /run/current-system/sw/bin/chown -R hydra:hydra /etc/nix/hydra.mcwhirter.io
+        /run/current-system/sw/bin/chmod 440 /etc/nix/hydra.mcwhirter.io/secret
+        /run/current-system/sw/bin/chmod 444 /etc/nix/hydra.mcwhirter.io/public
+        # create cache
+        /run/current-system/sw/bin/install -d -m 755 /var/lib/hydra/cache
+        /run/current-system/sw/bin/chown -R hydra-queue-runner:hydra /var/lib/hydra/cache
+        # done
+        touch ~hydra/.setup-is-complete
+      fi
+    '';
+  };
+  nix.trustedUsers = ["hydra" "hydra-evaluator" "hydra-queue-runner"];
+  nix.buildMachines = [
+    {
+      hostName = "localhost";
+      systems = [ "x86_64-linux" "i686-linux" ];
+      maxJobs = 6;
+      # for building VirtualBox VMs as build artifacts, you might need other
+      # features depending on what you are doing
+      supportedFeatures = [ ];
+    }
+  ];
+}
diff --git a/Hosts/cuallaidh.nix b/Hosts/cuallaidh.nix
index 2aad5e7..dc67ee4 100644
--- a/Hosts/cuallaidh.nix
+++ b/Hosts/cuallaidh.nix
@@ -5,8 +5,16 @@
     { config, pkgs, lib, ... }:
 
     {
+
+      imports =
+        [
+          ../Deployments/hydra.nix
+        ];
+
       deployment.targetHost = "172.105.197.118";
 
-      networking.hostName = "cuallaidh";      # Define your hostname.
+      networking.hostName = "cuallaidh";   # Define your hostname.
+
+      system.stateVersion = "19.03";       # The version of NixOS originally installed
     };
 }
diff --git a/Networks/Linode.nix b/Networks/Linode.nix
index fc1a801..4ddf25a 100644
--- a/Networks/Linode.nix
+++ b/Networks/Linode.nix
@@ -36,22 +36,11 @@
         domain = "mcwhirter.io";
         firewall = {
           enable = true;
-          allowedTCPPorts = [  ];
+          allowedTCPPorts = [ 80 443 ];
           trustedInterfaces = [ "lo" ];
         };
       };
-  };
 
-  cuallaidh =
-    { config, pkgs, lib, ... }:
-
-    {
-      # This value determines the NixOS release with which your system is to be
-      # compatible, in order to avoid breaking some software such as database
-      # servers. You should change this only after NixOS release notes say you
-      # should.
-      system.stateVersion = "19.03"; # Did you read the comment?
-      system.autoUpgrade.enable = false;
-      system.autoUpgrade.channel = https://nixos.org/channels/nixos-19.03;
+      system.autoUpgrade.enable = false;  # Disabled as it conflicts with NixOps
     };
 }