Add github actions

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

@@ -0,0 +1,36 @@
+name: Nix Flake actions
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - main
+
+jobs:
+  nix-matrix:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install Nix
+        uses: DeterminateSystems/nix-installer-action@v4
+      - id: set-matrix
+        name: Generate Nix Matrix
+        run: |
+          set -Eeu
+          echo "matrix=$(nix eval --json '.#githubActions.matrix')" >> "$GITHUB_OUTPUT"
+
+  nix-build:
+    needs: nix-matrix
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix: ${{fromJSON(needs.nix-matrix.outputs.matrix)}}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install Nix
+        uses: DeterminateSystems/nix-installer-action@v4
+      - name: Run Nix cache
+        uses: DeterminateSystems/magic-nix-cache-action@v1
+      - run: nix build -L ".#${{ matrix.attr }}"

flake.nix

@@ -2,15 +2,21 @@
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
     flake-utils.url = "github:numtide/flake-utils";
+    nix-github-actions.url = "github:nix-community/nix-github-actions";
+    nix-github-actions.inputs.nixpkgs.follows = "nixpkgs";
   };
 
-  outputs = { self, nixpkgs, flake-utils }:
+  outputs = { self, nixpkgs, flake-utils, nix-github-actions }:
     let
       inherit (nixpkgs) lib;
     in
     {
-      libChecks = (import ./lib { inherit lib; }).tests;
+      githubActions = nix-github-actions.lib.mkGithubMatrix {
+        checks = { inherit (self.checks) x86_64-linux; };
+      };
+
       lib = builtins.removeAttrs (import ./lib { inherit lib; }) [ "tests" ];
+
     } // flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = nixpkgs.legacyPackages.${system};