From b2adc5926ef44b951b74cbcda4653b7ea8a8491e Mon Sep 17 00:00:00 2001
From: Tom Prince <tom.prince@hocat.ca>
Date: Thu, 2 Sep 2021 21:25:26 -0600
Subject: [PATCH] Expose eval as nix attribute.

---
 data/eval-machines.nix |  4 ++--
 default.nix            | 52 +++++++++++++++++++++++-------------------
 2 files changed, 31 insertions(+), 25 deletions(-)

diff --git a/data/eval-machines.nix b/data/eval-machines.nix
index a4bcda6..8cba819 100644
--- a/data/eval-machines.nix
+++ b/data/eval-machines.nix
@@ -1,9 +1,9 @@
 # Completely stripped down version of nixops' evaluator
-{ networkExpr }:
+{ networkExpr, pkgs ? {} }:
 
 let
   network      = import networkExpr;
-  nwPkgs       = network.network.pkgs or {};
+  nwPkgs       = network.network.pkgs or pkgs;
   lib          = network.network.lib or nwPkgs.lib or (import <nixpkgs/lib>);
   evalConfig   = network.network.evalConfig or ((nwPkgs.path or <nixpkgs>) + "/nixos/lib/eval-config.nix");
   runCommand   = network.network.runCommand or nwPkgs.runCommand or ((import <nixpkgs> {}).runCommand);
diff --git a/default.nix b/default.nix
index 58d97bd..fcbfb5b 100644
--- a/default.nix
+++ b/default.nix
@@ -3,35 +3,41 @@
 , version ? "dev"
 }:
 
-pkgs.buildGoModule rec {
-  name = "morph-unstable-${version}";
-  inherit version;
+let
+  morph = pkgs.buildGoModule rec {
+    name = "morph-unstable-${version}";
+    inherit version;
 
-  nativeBuildInputs = with pkgs; [ go-bindata ];
+    nativeBuildInputs = with pkgs; [ go-bindata ];
 
-  src = pkgs.nix-gitignore.gitignoreSource [] ./.;
+    src = pkgs.nix-gitignore.gitignoreSource [] ./.;
 
-  buildFlagsArray = ''
-    -ldflags=
-    -X
-    main.version=${version}
-  '';
+    buildFlagsArray = ''
+      -ldflags=
+      -X
+      main.version=${version}
+    '';
 
-  vendorSha256 = "08zzp0h4c4i5hk4whz06a3da7qjms6lr36596vxz0d8q0n7rspr9";
+    vendorSha256 = "08zzp0h4c4i5hk4whz06a3da7qjms6lr36596vxz0d8q0n7rspr9";
 
-  postPatch = ''
-    go-bindata -pkg assets -o assets/assets.go data/
-  '';
+    postPatch = ''
+      go-bindata -pkg assets -o assets/assets.go data/
+    '';
 
-  postInstall = ''
-    mkdir -p $lib
-    cp -v ./data/*.nix $lib
-  '';
+    postInstall = ''
+      mkdir -p $lib
+      cp -v ./data/*.nix $lib
+    '';
 
-  outputs = [ "out" "lib" ];
+    outputs = [ "out" "lib" ];
 
-  meta = {
-    homepage = "https://github.com/DBCDK/morph";
-    description = "Morph is a NixOS host manager written in Golang.";
+    passthru = {
+      eval = args@{...}: (import (morph.lib + "/eval-machines.nix")) ({ inherit pkgs; } // args);
+    };
+
+    meta = {
+      homepage = "https://github.com/DBCDK/morph";
+      description = "Morph is a NixOS host manager written in Golang.";
+    };
   };
-}
+in morph