pass sources via specialArgs (#464)

this gets rid of ugly in-place imports and upward paths

Reviewed-on: Fediversity/Fediversity#464
Reviewed-by: kiara Grouwstra <kiara@procolix.eu>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-committed-by: Valentin Gagarin <valentin.gagarin@tweag.io>

infra/common/proxmox-qemu-vm.nix

@@ -1,15 +1,4 @@
-let
+{ sources, ... }:
-  # pulling this in manually over from module args resolves an infinite recursion.
-  # FIXME: instead untangle `//infra/flake-part.nix` and make it stop passing wild functions.
-  # move moving towards a portable-services-like pattern where some things are submodules.
-  # Right now those wild functions are for parameterising a bunch of things,
-  # and the modular way to do that would be options --
-  # obviously you can't use those for `imports`,
-  # so one way to decouple fixpoints is to isolate them into submodules.
-  # Therefore one approach would be to try to go down the call graph,
-  # and see where what's currently a function could be a `submodule` field of something else.
-  sources = import ../../npins;
-in
 {
   _class = "nixos";
 

infra/flake-part.nix

@@ -27,7 +27,6 @@ let
       _module.args = {
         inherit
           inputs
-          sources
           keys
           secrets
           ;
@@ -37,6 +36,10 @@ let
         ./common/proxmox-qemu-vm.nix
       ];
 
+      nixos.specialArgs = {
+        inherit sources;
+      };
+
       imports =
         [
           ./common/resource.nix
@@ -66,17 +69,33 @@ let
     vmNames:
     { providers, ... }:
     {
-      providers.local = inputs.nixops4.modules.nixops4Provider.local;
+      # XXX: this type merge is for adding `specialArgs` to resource modules
-      resources = genAttrs vmNames (vmName: {
+      options.resources = mkOption {
-        type = providers.local.exec;
+        type =
-        imports = [
+          with lib.types;
-          inputs.nixops4-nixos.modules.nixops4Resource.nixos
+          lazyAttrsOf (submoduleWith {
-          (makeResourceModule {
+            class = "nixops4Resource";
-            inherit vmName;
+            modules = [ ];
-            isTestVm = false;
+            # TODO(@fricklerhandwerk): we may want to pass through all of `specialArgs`
-          })
+            # once we're sure it's sane. leaving it here for better control during refactoring.
-        ];
+            specialArgs = {
-      });
+              inherit sources;
+            };
+          });
+      };
+      config = {
+        providers.local = inputs.nixops4.modules.nixops4Provider.local;
+        resources = genAttrs vmNames (vmName: {
+          type = providers.local.exec;
+          imports = [
+            inputs.nixops4-nixos.modules.nixops4Resource.nixos
+            (makeResourceModule {
+              inherit vmName;
+              isTestVm = false;
+            })
+          ];
+        });
+      };
     };
   makeDeployment' = vmName: makeDeployment [ vmName ];
 

machines/dev/fedi201/fedipanel.nix

@@ -1,17 +1,17 @@
 {
   config,
+  sources,
   ...
 }:
 let
   name = "panel";
-  sources = import ../../../npins;
 in
 {
   _class = "nixos";
 
   imports = [
-    (import ../../../panel { }).module
+    (../../../panel { }).module
-    (import "${sources.home-manager}/nixos")
+    "${sources.home-manager}/nixos"
   ];
 
   security.acme = {

panel/default.nix

@@ -45,7 +45,7 @@ in
     '';
   };
 
-  module = import ./nix/configuration.nix;
+  module = ./nix/configuration.nix;
   tests = pkgs.callPackage ./nix/tests.nix { };
 
   # re-export inputs so they can be overridden granularly