feat: finish transition to flake-parts

nix/hosts.nix

@@ -1,70 +1,63 @@
-inputs: let
-  inherit (inputs) self;
-  inherit
-    (inputs.nixpkgs.lib)
-    concatMapAttrs
-    filterAttrs
-    flip
-    mapAttrs
-    mapAttrs'
-    nameValuePair
-    nixosSystem
-    ;
+{inputs, ...}: {
+  flake = {
+    config,
+    lib,
+    ...
+  }: let
+    inherit
+      (lib)
+      concatMapAttrs
+      filterAttrs
+      flip
+      genAttrs
+      mapAttrs
+      mapAttrs'
+      nameValuePair
+      ;
 
-  # Creates a new nixosSystem with the correct specialArgs, pkgs and name definition
-  mkHost = {minimal}: name: hostCfg: let
-    pkgs = self.pkgs.${hostCfg.system};
-  in
-    nixosSystem {
-      specialArgs = {
-        # Use the correct instance lib that has our overlays
-        inherit (pkgs) lib;
-        inherit (self) nodes globals;
-        inherit inputs minimal;
+    # Creates a new nixosSystem with the correct specialArgs, pkgs and name definition
+    mkHost = {minimal}: name: let
+      pkgs = config.pkgs.x86_64-linux; # FIXME: NOOOOOOOOOOOOOOOOOOOOOOO
+    in
+      inputs.nixpkgs.lib.nixosSystem {
+        specialArgs = {
+          # Use the correct instance lib that has our overlays
+          inherit (pkgs) lib;
+          inherit (config) nodes globals;
+          inherit inputs minimal;
+        };
+        modules = [
+          {
+            node.name = name;
+            node.secretsDir = ../hosts/${name}/secrets;
+          }
+          ../hosts/${name}
+        ];
       };
-      modules = [
-        {
-          # We cannot force the package set via nixpkgs.pkgs and
-          # inputs.nixpkgs.nixosModules.readOnlyPkgs, since some nixosModules
-          # like nixseparatedebuginfod depend on adding packages via nixpkgs.overlays.
-          # So we just mimic the options and overlays defined by the passed pkgs set.
-          nixpkgs.hostPlatform = hostCfg.system;
-          nixpkgs.overlays = pkgs.overlays;
-          nixpkgs.config = pkgs.config;
-          node.name = name;
-          node.secretsDir = ../hosts/${name}/secrets;
-        }
-        ../hosts/${name}
-      ];
-    };
 
-  # 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.fromTOML (builtins.readFile ../hosts.toml);
-  # Get all hosts of type "nixos"
-  nixosHosts = filterAttrs (_: x: x.type == "nixos") hosts;
-  # Process each nixosHosts declaration and generatea nixosSystem definitions
-  nixosConfigurations = flip mapAttrs nixosHosts (mkHost {minimal = false;});
-  nixosConfigurationsMinimal = flip mapAttrs nixosHosts (mkHost {minimal = true;});
+    # Get all folders in hosts/
+    hosts = builtins.attrNames (filterAttrs (_: type: type == "directory") (builtins.readDir ../hosts));
+  in {
+    nixosConfigurations = genAttrs hosts (mkHost {minimal = false;});
+    nixosConfigurationsMinimal = 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`.
-  guestConfigs = flip concatMapAttrs self.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
-        )
-    ));
-in {
-  inherit
-    hosts
-    guestConfigs
-    nixosConfigurations
-    nixosConfigurationsMinimal
-    ;
+    # 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`.
+    guestConfigs = 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.guestConfigs;
+    # Add a shorthand to easily target toplevel derivations
+    "@" = mapAttrs (_: v: v.config.system.build.toplevel) config.nodes;
+  };
 }