readme

CHANGELOG.md

@@ -5,6 +5,7 @@
     - Add new config `nixci.*.*.systems` acting as a whitelist of systems to build that subflake.
     - Add `--build-systems` option to build on an arbitrary systems (\#39)
     - Allow selecting sub-flake to build, e.g.: `nixci .#default.myflake`  (\#45)
+    - Add subcommand to generate Github Actions matrix (\#50)
 - Fixes
     - Fix regression in Nix 2.19+ (`devour-flake produced an outpath with no outputs`) (\#35)
     - Evaluate OS configurations for current system only (\#38)

README.md

@@ -43,6 +43,8 @@ $ nixci .#default.dev
 
 ### Using in Github Actions
 
+#### Standard Runners
+
 Add the following to your workflow file,
 
 ```yaml
@@ -58,6 +60,28 @@ Add the following to your workflow file,
       - run: nixci
 ```
 
+#### Self-hosted Runners with Job Matrix
+
+```yaml
+jobs:
+  configure:
+    runs-on: self-hosted
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+     - uses: actions/checkout@v4
+     - id: set-matrix
+       run: echo "matrix=$(nixci dump-github-actions-matrix --systems=aarch64-linux,aarch64-darwin | jq -c .)" >> $GITHUB_OUTPUT
+  nix:
+    runs-on: self-hosted
+    needs: configure
+    strategy:
+      matrix: ${{ fromJson(needs.configure.outputs.matrix) }}
+    steps:
+      - uses: actions/checkout@v4
+      - run: nixci build --build-systems "github:nix-systems/${{ matrix.system }}" .#default.${{ matrix.subflake}}
+```
+
 ## Configuring
 
 By default, `nixci` will build the top-level flake, but you can tell it to build sub-flakes by adding the following output to your top-level flake: