feat: upstream node generation

2025-02-06 21:14:42 +01:00 · 2025-02-06 21:14:42 +01:00 · 93b08971cf
commit 93b08971cf
parent f1a3f0303b
9 changed files with 268 additions and 48 deletions
--- a/flake-modules/nodes.nix
+++ b/flake-modules/nodes.nix
@ -0,0 +1,110 @@
+{
+  inputs,
+  self,
+  lib,
+  config,
+  ...
+}:
+let
+  inherit (lib) mkOption types;
+  topConfig = config;
+in
+{
+  options.node = {
+    path = mkOption {
+      type = types.path;
+      description = "The path containing your host definitions";
+    };
+    nixpkgs = mkOption {
+      type = types.path;
+      default = inputs.nixpkgs;
+      description = "The path to your nixpkgs.";
+    };
+  };
+  config.flake =
+    {
+      config,
+      lib,
+      ...
+    }:
+    let
+      inherit (lib)
+        concatMapAttrs
+        filterAttrs
+        flip
+        genAttrs
+        mapAttrs'
+        nameValuePair
+        ;
+
+      # Creates a new nixosSystem with the correct specialArgs, pkgs and name definition
+      mkHost =
+        { minimal }:
+        name:
+        let
+          pkgs = config.pkgs.x86_64-linux;
+        in
+        (import "${topConfig.node.nixpkgs}/nixos/lib/eval-config.nix") {
+          system = null;
+          specialArgs = {
+            # Use the correct instance lib that has our overlays
+            inherit (pkgs) lib;
+            inherit (config) nodes globals;
+            inherit minimal;
+            extraModules = [
+              ../modules
+            ] ++ topConfig.globals.optModules;
+            inputs = inputs // {
+              inherit (topConfig.node) nixpkgs;
+            };
+          };
+          modules = [
+            (
+              { config, ... }:
+              {
+                node.name = name;
+                node.secretsDir = topConfig.node.path + "/${name}/secrets";
+                nixpkgs.pkgs = self.pkgs.${config.nixpkgs.hostPlatform.system};
+              }
+            )
+            (topConfig.node.path + "/${name}")
+            ../modules
+          ] ++ topConfig.globals.optModules;
+        };
+
+      # Load the list of hosts that this flake defines, which
+      # associates the minimum amount of metadata that is necessary
+      # to instanciate hosts correctly.
+      hosts = builtins.attrNames (
+        filterAttrs (_: type: type == "directory") (builtins.readDir topConfig.node.path)
+      );
+    in
+    # Process each nixosHosts declaration and generatea nixosSystem definitions
+    {
+      nixosConfigurations = genAttrs hosts (mkHost {
+        minimal = false;
+      });
+      minimalConfigurations = genAttrs hosts (mkHost {
+        minimal = true;
+      });
+
+      # True NixOS nodes can define additional guest nodes that are built
+      # together with it. We collect all defined guests from each node here
+      # to allow accessing any node via the unified attribute `nodes`.
+      guestConfigurations = flip concatMapAttrs config.nixosConfigurations (
+        _: node:
+        flip mapAttrs' (node.config.guests or { }) (
+          guestName: guestDef:
+          nameValuePair guestDef.nodeName (
+            if guestDef.backend == "microvm" then
+              node.config.microvm.vms.${guestName}.config
+            else
+              node.config.containers.${guestName}.nixosConfiguration
+          )
+        )
+      );
+      # All nixosSystem instanciations are collected here, so that we can refer
+      # to any system via nodes.<name>
+      nodes = config.nixosConfigurations // config.guestConfigurations;
+    };
+}