switch to a full networkd setup

shared/commons/mesh.nix

@@ -13,8 +13,8 @@ let
     buildSecret = zone: id: {
         "wg-private-zone-${toString zone}-id-${toString id}" = {
             file = ./../../secrets/wireguard + ( "/wg-private-zone-" + toString zone + "-id-" + toString id + ".age" );
-            owner = "root";
-            group = "root";
+            owner = "systemd-network";
+            group = "systemd-network";
         };
     };
     generatedSecrets = lib.mapAttrsToList (name: node: buildSecret node.zone node.id) nodes;
@@ -22,71 +22,57 @@ let
     # Filter itself out of the peer list
     peerConfigs = lib.filterAttrs (_peerName: peerConfig: (peerConfig.zone != myZone) || (peerConfig.id != myId)) nodes;
     
-    peers = lib.mapAttrsToList (peerName: peerConfig: {
-        name = "${peerName}";
-        publicKey = peerConfig.wg-pub;
-        allowedIPs = [
+    interfacePeers = lib.mapAttrsToList (peerName: peerConfig: {
+        PublicKey = peerConfig.wg-pub;
+        AllowedIPs = [
             "172.19.${toString peerConfig.zone}.${toString peerConfig.id}/32"
             "fc00::${toString peerConfig.zone}:${toString peerConfig.id}/128"
         ] ++ lib.optionals (lib.elem peerName mapping.bastion) [
             "172.19.${toString (peerConfig.zone + 127)}.0/24"
             "fc00:f::${toString (peerConfig.zone + 127)}:0/112"
         ];
-        endpoint = "${builtins.head (builtins.split "/" peerConfig.ip4)}:51820";
-        persistentKeepalive = 25;
+        Endpoint = "${builtins.head (builtins.split "/" peerConfig.ip4)}:51820";
+        PersistentKeepalive = 25;
     }) peerConfigs;
     
-    interfaces = {
-        "mesh" = {
-            ips = [
-                "172.19.${toString myZone}.${toString myId}/17"
-                "fc00::${toString myZone}:${toString myId}/112"
-            ];
-            privateKeyFile = config.age.secrets."wg-private-zone-${toString myZone}-id-${toString myId}".path;
-            listenPort = 51820;
-            peers = peers;
-        };
+    interfaceConfig = {
+        PrivateKeyFile = config.age.secrets."wg-private-zone-${toString myZone}-id-${toString myId}".path;
+        ListenPort = 51820;
     };
 
-    generateRoute = peerName: peerConfig: ''
-        # Return path for mgmt trafic
-        ${if lib.elem peerName mapping.bastion then ''
-            ${pkgs.iproute2}/bin/ip route replace 172.19.${toString (peerConfig.zone + 127)}.0/24 via 172.19.${toString peerConfig.zone}.${toString peerConfig.id} dev mesh
-            ${pkgs.iproute2}/bin/ip -6 route replace fc00:f::${toString (peerConfig.zone + 127)}:0/112 via fc00::${toString peerConfig.zone}:${toString peerConfig.id} dev mesh
-        '' else ""}
-    '';
+    # Return route for mgmt traffic
+    bastionConfigs = lib.filterAttrs (peerName: _peerConfig: lib.elem peerName mapping.bastion) peerConfigs;
 
-    generateAfter = peerName: peerConfig: "wireguard-mesh.target";
-
-    routes = lib.mapAttrsToList (name: peer: generateRoute name peer) peerConfigs;
-    afters = lib.mapAttrsToList (name: peer: generateAfter name peer) peerConfigs;
-
-    wireguardStaticRoute = pkgs.writeShellScriptBin "wireguardStaticRoute" ''
-        ${lib.concatStrings routes}
-    '';
+    rtwg4 = map (node: { 
+        Gateway = "172.19.${toString node.zone}.${toString node.id}"; 
+        Destination = "172.19.${toString (node.zone + 127)}.0/24"; 
+    }) (lib.attrValues bastionConfigs);
+    
+    rtwg6 = map (node: { 
+        Gateway = "fc00::${toString node.zone}:${toString node.id}"; 
+        Destination = "fc00:f::${toString (node.zone + 127)}:0/112"; 
+    }) (lib.attrValues bastionConfigs);
 in
 {
     age.secrets = lib.lists.foldl' (acc: set: lib.attrsets.recursiveUpdate acc set) {} generatedSecrets;
 
-    # Networkd backend introduce in 25.05
-    # No independant target are generated 
-    # when using networkd as a backend
-    # We need them, see below
-    networking.wireguard.useNetworkd = false;
-
-    # Return all WireGuard interfaces for each node
-    networking.wireguard.interfaces = interfaces;
-
-    # Execute custom routing for wireguard
-    systemd.services.wireguardStaticRouting = {
-        wantedBy = [ "multi-user.target" ];
-        # Thus we need specific target to be reached to run it
-        after = afters;
-        description = "Add custom ip route for wireguard.";
-        serviceConfig = {
-            Type = "oneshot";
-            User = "root";
-            ExecStart = "${wireguardStaticRoute}/bin/wireguardStaticRoute";
+    # Build Mesh interface
+    systemd.network = {
+        netdevs."mesh" = {
+            netdevConfig = {
+                Name = "mesh";
+                Kind = "wireguard";
+            };
+            wireguardConfig = interfaceConfig;
+            wireguardPeers = interfacePeers;
+        };
+        networks."mesh" = {
+            matchConfig.Name = "mesh";
+            address = [
+                "172.19.${toString myZone}.${toString myId}/17"
+                "fc00::${toString myZone}:${toString myId}/112"
+            ];
+            routes = rtwg4 ++ rtwg6;
         };
     };
 }

shared/commons/networking.nix

@@ -35,11 +35,5 @@ in
                 linkConfig.RequiredForOnline = "routable";
             };
         };
-        
-        config.addRouteTablesToIPRoute2 = true;
-        config.routeTables = {
-            # Act as a route bin
-            off = 999;
-        };
     };
 }