Still a work in progress.

flake.lock

@@ -233,16 +233,16 @@
     },
     "nixpkgs_4": {
       "locked": {
-        "lastModified": 1735563628,
-        "narHash": "sha256-OnSAY7XDSx7CtDoqNh8jwVwh4xNL/2HaJxGjryLWzX8=",
+        "lastModified": 1764316264,
+        "narHash": "sha256-82L+EJU+40+FIdeG4gmUlOF1jeSwlf2AwMarrpdHF6o=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "b134951a4c9f3c995fd7be05f3243f8ecd65d798",
+        "rev": "9a7b80b6f82a71ea04270d7ba11b48855681c4b0",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-24.05",
+        "ref": "nixos-25.05",
         "repo": "nixpkgs",
         "type": "github"
       }

flake.nix

@@ -2,7 +2,7 @@
   description = "Metanix static flake: meta.nix → addressing, deploy-rs, disko, nixos-anywhere";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
     deploy-rs.url = "github:serokell/deploy-rs";
     disko.url = "github:nix-community/disko";
     nixos-anywhere.url = "github:numtide/nixos-anywhere";

meta.nix

@@ -47,7 +47,6 @@
           deimos = {
             role = "server";
             hw-address = "10:98:36:a0:2c:b2";
-            interface = "eno2";
             aliases = [
               "kasear.net"
               "cloud.kasear.net"
@@ -115,6 +114,7 @@
           phobos = {
             role = "server";
             hw-address = "10:98:36:a9:4a:26";
+            interface = "eno2";
             aliases = [
               "pbx.kasear.net"
               "private.kasear.net"

modules/metanix/networkd.nix

@@ -1,45 +1,34 @@
 { lib, config, ... }:
 
 let
-  inherit (lib) mkOption mkIf types attrValues filterAttrs head;
+  inherit (lib) mkOption mkIf types;
 
   metanix = config.metanix or { };
 
-  # For now, tell Metanix "which host am I?"
   thisHostName = config.metanix.thisHost or config.networking.hostName;
 
-  host = metanix.network.hosts.${thisHostName} or null;
+  hosts = (metanix.network or { }).hosts or { };
+  host = hosts.${thisHostName} or null;
 
-  # Find the subnet this host belongs to by matching IP prefix
-  # VERY SIMPLE: relies on your rigid addressing scheme
-  findSubnetForHost =
-    ip:
-    let
-      subnets = metanix.network.subnets or { };
-      matches =
-        filterAttrs
-          (_: s: lib.strings.hasPrefix (lib.strings.concatStringsSep "." (lib.take 3 (lib.splitString "." s.cidr)))
-            (lib.strings.concatStringsSep "." (lib.take 3 (lib.splitString "." ip))))
-          subnets;
-    in
-    if matches == { }
-    then null
-    else head (attrValues matches);
+  subnets = (metanix.network or { }).subnets or { };
+  subnet =
+    if host != null && host ? subnetKey
+    then subnets.${host.subnetKey} or null
+    else null;
 
   cidrPrefix =
     cidr:
     let
-      # match "10.1.32.0/19" → [ "19" ]
       m = builtins.match ".*/([0-9]+)" cidr;
     in
-    if m == null then 32 else builtins.fromJSON (head m);
-
-  hostSubnet =
-    if host == null then null else findSubnetForHost host."ip-address";
+    if m == null then 32 else builtins.fromJSON (builtins.head m);
 
   prefixLen =
-    if hostSubnet == null then 32 else cidrPrefix hostSubnet.cidr;
+    if subnet == null then 32 else cidrPrefix subnet.cidr;
 
+  unitName =
+    if host == null then "metanix"
+    else "10-${host.location}-${host.subnetType}-${host.interface}";
 in
 {
   options.metanix.thisHost = mkOption {
@@ -54,24 +43,16 @@ in
   config = mkIf (host != null && host ? interface) {
     systemd.network.enable = true;
 
-    systemd.network.networks."10-metanix-${host.interface}" = {
-      matchConfig = {
-        Name = host.interface;
-      };
+    systemd.network.networks.${unitName} = {
+      matchConfig.Name = host.interface;
 
-      # Static address from Metanix
       address = [
         "${host."ip-address"}/${toString prefixLen}"
       ];
 
-      # Optional: match MAC if present
-      linkConfig = lib.mkIf (host ? "hw-address") {
+      linkConfig = mkIf (host ? "hw-address") {
         MACAddress = host."hw-address";
       };
-
-      # TODO later: gateway & DNS resolution from metanix.network / policy
-      # gateway = "...";
-      # dns = [ ... ];
     };
   };
 }

tests/networkd-phobos.nix

@@ -2,49 +2,35 @@
 let
   system = "x86_64-linux";
 
-  # Bring in nixpkgs and lib
+  # Grab nixpkgs lib for convenience
   pkgs = import <nixpkgs> { inherit system; };
   lib = pkgs.lib;
 
-  # Your world + addressing lib
+  # Metanix world + addressing
   meta = import ../meta.nix;
   addressing = import ../lib/addressing { inherit lib; };
 
-  # NixOS module system library
-  nixosLib = import <nixpkgs/nixos/lib> {
-    inherit lib;
+  network = addressing.mkNetworkFromSpec meta;
+
+  # Fake NixOS config that your module expects
+  config = {
+    networking.hostName = "phobos";
+    metanix = {
+      thisHost = "phobos";
+      inherit network;
+    };
   };
 
-  # All standard NixOS modules (as a list)
-  baseModules = import <nixpkgs/nixos/modules/module-list.nix>;
-
-  # Evaluate modules as if this were a NixOS system
-  evalResult = nixosLib.evalModules {
-    modules =
-      baseModules
-      ++ [
-        # Metanix core wiring (meta + addressing)
-        ../modules/metanix/core.nix
-
-        # systemd-networkd integration
-        ../modules/metanix/networkd.nix
-
-        # Local stub: "this machine is phobos"
-        {
-          networking.hostName = "phobos";
-          metanix.thisHost = "phobos";
-        }
-      ];
-
-    # Args passed to all modules: { lib, pkgs, system, meta, addressing, modulesPath, ... }
-    specialArgs = {
-      inherit lib pkgs system meta addressing;
-      modulesPath = builtins.toString <nixpkgs/nixos/modules>;
-    };
+  # Call the networkd module directly as a function
+  networkdModule = import ../modules/metanix/networkd.nix {
+    inherit lib config;
   };
 in
 {
-  systemdNetwork = evalResult.config.systemd.network;
-  metanixHost = evalResult.config.metanix.network.hosts.phobos;
-  metanixSubnet = evalResult.config.metanix.network.subnets."home-main";
+  # Raw Metanix view
+  metanixHost = network.hosts.phobos;
+  metanixSubnet = network.subnets."home-main";
+
+  # What the module actually emits
+  systemdNetwork = networkdModule.config.systemd.network;
 }