Add wireguard service

configuration/services/wireguard.nix

@@ -0,0 +1,50 @@
+{config, ...}: {
+  systemd.network = {
+    netdevs = {
+      "20-wg0" = {
+        netdevConfig = {
+          Name = "wg0";
+          Kind = "wireguard";
+          Description = "wg0 - wireguard tunnel";
+        };
+
+        wireguardConfig = {
+          ListenPort = 51820;
+          PrivateKeyFile = config.sops.secrets."wireguard/server-key".path;
+          # Public key: 73z3Pga/2BCxETYM/qCT2FM1JUCUvQ+Cp+8ROxjhu0w=
+        };
+
+        wireguardPeers = [
+          {
+            # yui
+            wireguardPeerConfig = {
+              AllowedIPs = ["10.45.249.2/32"];
+              PublicKey = "5mlnqEVJWks5OqgeFA2bLIrvST9TlCE81Btl+j4myz0=";
+            };
+          }
+
+          {
+            # yuanyuan
+            wireguardPeerConfig = {
+              AllowedIPs = ["10.45.249.10/32"];
+              PublicKey = "0UsFE2atz/O5P3OKQ8UHyyyGQNJbp1MeIWUJLuoerwE=";
+            };
+          }
+        ];
+      };
+    };
+
+    networks = {
+      "20-wg0" = {
+        matchConfig.Name = "wg0";
+
+        networkConfig.Address = [
+          "10.45.249.1/24"
+          # TODO(tlater): Add IPv6 whenever that becomes relevant
+        ];
+
+        linkConfig.RequiredForOnline = "no";
+      };
+    };
+  };
+}