hydra: setup bonded network

hosts/hydra/default.nix

@@ -3,6 +3,7 @@
 {
   imports = [
     ./hardware-configuration.nix
+    ./network.nix
     ./hydra.nix
     ./cache.nix
     ./updater.nix
@@ -41,15 +42,6 @@
   networking = {
     hostName = "hydra";
     firewall.enable = false;
-    defaultGateway = "172.20.73.1";
-    interfaces.enp3s0 = {
-      useDHCP = false;
-      tempAddress = "disabled";
-      ipv4.addresses = [{
-        address = "172.20.73.49";
-        prefixLength = zentralwerk.lib.config.site.net.serv.subnet4Len;
-      }];
-    };
     nameservers = [ "172.20.73.8" "9.9.9.9" ];
   };
 

hosts/hydra/network.nix

@@ -0,0 +1,67 @@
+{ zentralwerk, config, lib, ... }:
+{
+  networking = {
+    useDHCP = false;
+    useNetworkd = true;
+  };
+
+  boot.kernelParams = [
+    # Prevents automatic creation of interface bond0 by the kernel
+    "bonding.max_bonds=0"
+  ];
+
+  systemd.network = {
+    enable = true;
+
+    netdevs = {
+      serv.netdevConfig = {
+        Kind = "bond";
+        Name = "serv";
+      };
+      # LACP
+      serv.bondConfig.Mode = "802.3ad";
+    };
+
+    networks = {
+      en = {
+        # physical ethernet ports
+        matchConfig.Name = "en*";
+        networkConfig = {
+          Bond = "serv";
+          LLDP = true;
+          EmitLLDP = true;
+        };
+      };
+      "serv" =
+        let
+          inherit (config.networking) hostName;
+          netConfig = zentralwerk.lib.config.site.net.serv;
+          address = netConfig.hosts4.${hostName};
+          prefixLen = netConfig.subnet4Len;
+        in
+          {
+            matchConfig.Name = "serv";
+            networkConfig = {
+              LLDP = true;
+              EmitLLDP = true;
+              DHCP = "no";
+              IPv6AcceptRA = "no";
+            };
+            addresses =
+              lib.optional (netConfig.hosts4 ? ${hostName}) {
+                addressConfig.Address = "${address}/${toString prefixLen}";
+              } ++
+              builtins.concatMap (hosts6:
+                lib.optional (hosts6 ? ${hostName}) {
+                  addressConfig.Address = "${hosts6.${hostName}}/64";
+                }
+              ) (builtins.attrValues netConfig.hosts6);
+
+            gateway = [
+              netConfig.hosts4.serv-gw
+              netConfig.hosts6.dn42.serv-gw
+            ];
+          };
+    };
+  };
+}