Adding more structure.

flake.nix

@@ -10,101 +10,60 @@
 
   outputs = { self, nixpkgs, deploy-rs, disko, nixos-anywhere, ... }:
     let
-      # Default architecture if meta.nix doesn't say otherwise
       system = "x86_64-linux";
 
-      pkgs = import nixpkgs {
-        inherit system;
-      };
-
+      pkgs = import nixpkgs { inherit system; };
       lib = pkgs.lib;
 
-      # Your mkIp / mkHostsFromSpec / mkSubnetsFromSpec, etc.
-      # This expects: lib/addressing/default.nix
       addressing = import ./lib/addressing {
         inherit lib;
       };
 
-      # User-provided world model.
       meta = import ./meta.nix;
 
-      # Uses your rewritten mkNetworkFromSpec that understands meta.nix shape.
-      network = addressing.mkNetworkFromSpec meta;
-
-      # Optional: meta.systems = { hostName = { system = "..."; modules = [ ... ]; ... }; ...; }
       systemsFromMeta = meta.systems or { };
     in
     {
-      #######################
-      # Library-style exports
-      #######################
-      lib = {
-        metanix = {
-          inherit meta network addressing;
-        };
+      lib.metanix = {
+        inherit meta addressing;
+        network = addressing.mkNetworkFromSpec meta;
       };
 
-      #############################
-      # Per-host NixOS configs
-      #
-      # Driven by meta.systems if present. Shape example:
-      # meta.systems = {
-      #   deimos = {
-      #     system = "x86_64-linux";
-      #     modules = [ ./hosts/deimos.nix ];
-      #     diskoConfig = ./disko/deimos.nix;  # optional
-      #     deployHost = "deimos.kasear.net";  # optional
-      #     deployUser = "root";               # optional
-      #   };
-      # };
-      #############################
       nixosConfigurations =
         lib.mapAttrs
           (name: sysCfg:
             let
               systemForHost = sysCfg.system or system;
+            in
+            lib.nixosSystem {
+              system = systemForHost;
 
-              pkgsForHost = import nixpkgs {
-                inherit systemForHost;
+              # Make meta + addressing available to all modules
+              specialArgs = {
+                inherit meta addressing;
               };
 
-              hostLib = pkgsForHost.lib;
-
-              # Optional disko module wiring if sysCfg.diskoConfig exists.
-              diskoModule =
-                if sysCfg ? diskoConfig then
-                  { imports = [ disko.nixosModules.disko sysCfg.diskoConfig ]; }
-                else
-                  { };
-            in
-            hostLib.nixosSystem {
-              system = systemForHost;
               modules =
                 (sysCfg.modules or [ ]) ++ [
-                  diskoModule
-                  ({ ... }: {
-                    _module.args = {
-                      inherit meta network addressing;
-                      hostName = name;
-                    };
-                  })
+                  ./modules/metanix-core.nix
+
+                  # Disko wiring if present
+                  (if sysCfg ? diskoConfig then
+                    { imports = [ disko.nixosModules.disko sysCfg.diskoConfig ]; }
+                  else
+                    { })
                 ];
             })
           systemsFromMeta;
 
-      ########################################
-      # deploy-rs integration
-      #
-      # Builds deploy.nodes using meta.systems + addressing.
-      ########################################
       deploy = {
         nodes =
           lib.mapAttrs
             (name: sysCfg:
               let
+                network = addressing.mkNetworkFromSpec meta;
                 hasNetworkHost = builtins.hasAttr name network.hosts;
                 hostInfo = if hasNetworkHost then network.hosts.${name} else null;
-
                 defaultHostname =
                   if hasNetworkHost then hostInfo.fqdn else "${name}.${meta.domain}";
               in
@@ -121,15 +80,9 @@
             systemsFromMeta;
       };
 
-      ########################################
-      # deploy-rs sanity checks
-      ########################################
       checks.${system}.deploy =
         deploy-rs.lib.${system}.deployChecks self.deploy;
 
-      ########################################
-      # nixos-anywhere convenience app
-      ########################################
       apps.${system}.nixos-anywhere = {
         type = "app";
         program =

modules/metanix-core.nix

@@ -0,0 +1,71 @@
+{ lib, meta, addressing, ... }:
+
+let
+  inherit (lib) mkOption types;
+in
+{
+  options.metanix = {
+    # Raw world spec, straight from meta.nix
+    meta = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      default = { };
+      description = "Raw Metanix world spec loaded from meta.nix.";
+    };
+
+    domain = mkOption {
+      type = types.str;
+      readOnly = true;
+      description = "Base DNS domain for this Metanix world.";
+    };
+
+    locations = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "Location tree from meta.nix.";
+    };
+
+    systems = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "System definitions from meta.nix.";
+    };
+
+    # Computed addressing
+    network = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "Computed addressing (hosts, subnets, etc.) from meta.nix.";
+    };
+
+    hosts = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "Shortcut for metanix.network.hosts.";
+    };
+
+    subnets = mkOption {
+      type = types.attrs;
+      readOnly = true;
+      description = "Shortcut for metanix.network.subnets.";
+    };
+  };
+
+  config.metanix =
+    let
+      world = meta;
+      network = addressing.mkNetworkFromSpec world;
+    in
+    {
+      meta = world;
+
+      domain = world.domain;
+      locations = world.locations or { };
+      systems = world.systems or { };
+      policy = world.policy or { };
+
+      inherit network;
+      hosts = network.hosts;
+      subnets = network.subnets;
+    };
+}