From 5e0dd4a80e140884e71ebd57b25d2a2c2a1a9e33 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matthias=20Ri=C3=9Fe?= <matthias.risze@t-online.de>
Date: Mon, 8 Jan 2024 19:57:16 +0100
Subject: [PATCH] Create GitHub Actions matrix from `nix flake show`

---
 .github/workflows/build-flake-outputs.yml | 43 +++++++++++++++++++++++
 .github/workflows/nix-github-actions.yml  | 36 -------------------
 2 files changed, 43 insertions(+), 36 deletions(-)
 create mode 100644 .github/workflows/build-flake-outputs.yml
 delete mode 100644 .github/workflows/nix-github-actions.yml

diff --git a/.github/workflows/build-flake-outputs.yml b/.github/workflows/build-flake-outputs.yml
new file mode 100644
index 0000000..7decb3a
--- /dev/null
+++ b/.github/workflows/build-flake-outputs.yml
@@ -0,0 +1,43 @@
+name: Build flake outputs
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  nix-matrix:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v24
+      - id: set-matrix
+        name: Generate matrix
+        run: |
+          matrix=$(
+            nix flake show --refresh --json "." |
+              jq '{ attr: ((path(.. | select(.type? == "derivation")) | map((if (. | contains(".")) then "\"" + . + "\"" else . end)) | join(".")),
+                           (path(.. | select(.type? == "nixos-configuration")) | map((if (. | contains(".")) then "\"" + . + "\"" else . end)) | join(".") | . + ".config.system.build.toplevel"))
+                  }' |
+              jq --slurp --compact-output
+          )
+          echo "matrix=$matrix" >> "$GITHUB_OUTPUT"
+
+  nix-build:
+    needs: nix-matrix
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include: ${{fromJSON(needs.nix-matrix.outputs.matrix)}}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v24
+      - uses: cachix/cachix-action@v12
+        with:
+          name: matrss
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+      - run: nix build -L '.#${{ matrix.attr }}'
diff --git a/.github/workflows/nix-github-actions.yml b/.github/workflows/nix-github-actions.yml
deleted file mode 100644
index 3fcd5cb..0000000
--- a/.github/workflows/nix-github-actions.yml
+++ /dev/null
@@ -1,36 +0,0 @@
-name: Nix Flake actions
-
-on:
-  pull_request:
-  push:
-    branches:
-      - main
-
-jobs:
-  nix-matrix:
-    runs-on: ubuntu-latest
-    outputs:
-      matrix: ${{ steps.set-matrix.outputs.matrix }}
-    steps:
-      - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@v24
-      - id: set-matrix
-        name: Generate Nix Matrix
-        run: |
-          set -Eeu
-          matrix="$(nix eval --json '.#githubActions.matrix')"
-          echo "matrix=$matrix" >> "$GITHUB_OUTPUT"
-
-  nix-build:
-    needs: nix-matrix
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix: ${{fromJSON(needs.nix-matrix.outputs.matrix)}}
-    steps:
-      - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@v24
-      - uses: cachix/cachix-action@v12
-        with:
-          name: matrss
-          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
-      - run: nix build -L ".#${{ matrix.attr }}"