networking: Set up static IP address

configuration/default.nix

@@ -51,10 +51,7 @@
 
   networking = {
     hostName = "tlaternet";
-
     usePredictableInterfaceNames = false;
-    useDHCP = false;
-    interfaces.eth0.useDHCP = true;
 
     firewall = {
       allowedTCPPorts = [
@@ -95,6 +92,50 @@
     };
   };
 
+  systemd.network = {
+    enable = true;
+
+    networks = {
+      "10-eth0.network" = {
+        matchConfig.Name = "eth0";
+
+        networkConfig = {
+          DHCP = "no";
+
+          Address = "178.79.137.55";
+          Gateway = "178.79.137.1/24";
+
+          Domains = "ip.linodeusercontent.com";
+          DNS = [
+            "178.79.182.5"
+            "176.58.107.5"
+            "176.58.116.5"
+            "176.58.121.5"
+            "151.236.220.5"
+            "212.71.252.5"
+            "212.71.253.5"
+            "109.74.192.20"
+            "109.74.193.20"
+            "109.74.194.20"
+            "2a01:7e00::9"
+            "2a01:7e00::3"
+            "2a01:7e00::c"
+            "2a01:7e00::5"
+            "2a01:7e00::6"
+            "2a01:7e00::8"
+            "2a01:7e00::b"
+            "2a01:7e00::4"
+            "2a01:7e00::7"
+            "2a01:7e00::2"
+          ];
+
+          IPv6PrivacyExtensions = "no";
+          IPv6AcceptRA = "yes";
+        };
+      };
+    };
+  };
+
   time.timeZone = "Europe/London";
 
   users.users.tlater = {