Add tent machine from xeon04

We moved the tent machine to the server room in the BSC building and is
now directly connected to the raccoon via NAT.

Fixes: #106
Reviewed-by: Aleix Boné <abonerib@bsc.es>

m/tent/configuration.nix

@@ -0,0 +1,38 @@
+{ config, pkgs, ... }:
+
+{
+  imports = [
+    ../common/xeon.nix
+    ../module/emulation.nix
+    ../module/debuginfod.nix
+  ];
+
+  # Select the this using the ID to avoid mismatches
+  boot.loader.grub.device = "/dev/disk/by-id/wwn-0x55cd2e414d537675";
+
+  networking = {
+    hostName = "tent";
+    interfaces.eno1.ipv4.addresses = [
+      {
+        address = "10.0.44.4";
+        prefixLength = 24;
+      }
+    ];
+
+    # Only BSC DNSs seem to be reachable from the office VLAN
+    nameservers = [ "84.88.52.35" "84.88.52.36" ];
+    defaultGateway = "10.0.44.1";
+  };
+
+  nix.settings = {
+    extra-substituters = [ "https://jungle.bsc.es/cache" ];
+    extra-trusted-public-keys = [ "jungle.bsc.es:pEc7MlAT0HEwLQYPtpkPLwRsGf80ZI26aj29zMw/HH0=" ];
+  };
+
+  services.prometheus.exporters.node = {
+    enable = true;
+    enabledCollectors = [ "systemd" ];
+    port = 9002;
+    listenAddress = "127.0.0.1";
+  };
+}