[WIP] set up nix-github-actions

Author: yvan-sraka

.github/workflows/nix-github-actions.yml

@@ -0,0 +1,31 @@
+name: Nix Flake actions
+
+on:
+  pull_request:
+  push:
+
+jobs:
+  nix-matrix:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v30
+      - id: set-matrix
+        name: Generate Nix Matrix
+        run: |
+          set -Eeu
+          matrix="$(nix eval --json '.#githubActions.matrix')"
+          echo "matrix=$matrix" >> "$GITHUB_OUTPUT"
+
+  nix-build:
+    name: ${{ matrix.name }} (${{ matrix.system }})
+    needs: nix-matrix
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix: ${{fromJSON(needs.nix-matrix.outputs.matrix)}}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v30
+      - run: nix build -L '.#${{ matrix.attr }}'

flake.lock

@@ -13,6 +13,8 @@
     treefmt-nix.inputs.nixpkgs.follows = "nixpkgs";
     git-hooks.url = "github:cachix/git-hooks.nix";
     git-hooks.inputs.nixpkgs.follows = "nixpkgs";
+    nix-github-actions.url = "github:nix-community/nix-github-actions";
+    nix-github-actions.inputs.nixpkgs.follows = "nixpkgs";
   };
 
   outputs =
@@ -35,6 +37,7 @@
         nix/nixpkgs.nix
         nix/packages
         nix/overlays
+        nix/github-actions.nix
       ];
     });
 }

flake.nix

@@ -0,0 +1,6 @@
+{ inputs, ... }:
+{
+  flake.githubActions = inputs.nix-github-actions.lib.mkGithubMatrix {
+    checks = inputs.nixpkgs.lib.getAttrs [ "x86_64-linux" ] inputs.self.checks;
+  };
+}