add overlay from module

.github/workflows/ci.yaml

@@ -51,7 +51,6 @@ jobs:
       - id: set-matrix
         run: echo "matrix=$(nix eval --json ".#matrix.x86_64-linux")" | tee $GITHUB_OUTPUT
 
-
   build:
     runs-on: ubuntu-latest
     needs: [check, matrix]
@@ -72,9 +71,23 @@ jobs:
           name: shelve-${{ matrix.target }}
           path: result/bin/shelve${{ matrix.artifactSuffix }}
 
+
+  build-nixpkgs:
+    runs-on: ubuntu-latest
+    needs: check
+    steps:
+      - uses: actions/checkout@v3
+      - uses: cachix/install-nix-action@v20
+      - uses: icewind1991/attic-action@v1
+        with:
+          name: ci
+          instance: https://cache.icewind.me
+          authToken: '${{ secrets.ATTIC_TOKEN }}'
+      - run: nix build .#shelve
+
   docker:
     runs-on: ubuntu-latest
-    needs: build
+    needs: build-nixpkgs
     steps:
       - name: Checkout code
         uses: actions/checkout@v3

flake.nix

@@ -102,6 +102,17 @@
     )
     // {
       overlays.default = import ./overlay.nix;
-      nixosModules.default = import ./module.nix;
+      nixosModules.default = {
+        pkgs,
+        config,
+        lib,
+        ...
+      }: {
+        imports = [./module.nix];
+        config = lib.mkIf config.services.shelve.enable {
+          nixpkgs.overlays = [self.overlays.default];
+          services.shelve.package = lib.mkDefault pkgs.shelve;
+        };
+      };
     };
 }

module.nix

@@ -35,7 +35,6 @@ in {
     };
 
     package = mkOption {
-      default = pkgs.shelve;
       type = types.package;
       defaultText = literalExpression "pkgs.shelve";
       description = "package to use";

overlay.nix

@@ -1,3 +1,3 @@
-prev: final: {
+final: prev: {
   shelve = final.callPackage ./package.nix {};
 }