workflow.yaml

name: Continuous integration

on:
  push:
    branches: master
  pull_request:
    branches: master
  workflow_dispatch: # allows manual triggering
  workflow_call: # allows call from another workflow
  schedule:
    - cron: '1 11 * * *'

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
  cancel-in-progress: ${{ github.ref != 'refs/heads/master' }}

jobs:
  test-nixpkgs:
    name: Build & Test - Nixpkgs - ${{ matrix.bzlmodEnabled && 'bzlmod' || 'workspace' }} ${{ matrix.withNixRemote && '- NixRemote ' || '' }}- ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os:
          - ubuntu-latest
          - macos-latest
        bzlmodEnabled:
          - true
          - false
        withNixRemote:
          - true
          - false
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v4
      - uses: cachix/install-nix-action@v24
        with:
          nix_path: nixpkgs=./docs/nixpkgs.nix
      - uses: ./.github/actions/configure_bazelrc
        with:
          buildbuddy_api_key: ${{ secrets.BUILDBUDDY_API_KEY }}
      - name: Start remote Nix server
        if: matrix.withNixRemote && matrix.os == 'ubuntu-latest'
        run: |
          # Generate temporary SSH keys.
          mkdir -p $HOME/.ssh
          mkdir -p .github/nix-server/keys
          ssh-keygen -t ed25519 -f .github/nix-server/keys/ci -C ci-nix-server -q -N ""

          docker build -t nix-server -f .github/nix-server/Dockerfile .
          docker run -d -p 2222:22 nix-server

          cp .github/nix-server/keys/* $HOME/.ssh/

          sudo cp .github/nix-server/config /etc/ssh/ssh_config
      - name: Build & test
        env:
          BZLMOD_ENABLED: ${{ matrix.bzlmodEnabled }}
          NIX_REMOTE_ENABLED: matrix.withNixRemote && matrix.os == 'ubuntu-latest'
        run: |
          if [ "$NIX_REMOTE_ENABLED" = "true" ]; then
            echo "Setting BAZEL_NIX_REMOTE env variable"
            export BAZEL_NIX_REMOTE=nix-server
          fi

          nix-shell --pure \
            --keep GITHUB_STEP_SUMMARY \
            --keep GITHUB_REPOSITORY \
            --keep BZLMOD_ENABLED \
            --keep BAZEL_NIX_REMOTE \
            --run 'bash .github/build-and-test'
  test-examples:
    name: Build & Test - Examples
    strategy:
      fail-fast: false
      matrix:
        os:
          - ubuntu-latest
          - macos-latest
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v4
      - uses: cachix/install-nix-action@v24
        with:
          nix_path: nixpkgs=./nixpkgs.nix
      - uses: ./.github/actions/configure_bazelrc
        with:
          buildbuddy_api_key: ${{ secrets.BUILDBUDDY_API_KEY }}
      - name: Build & test
        run: |
          skip() {
            echo "Will skip $(head -n1 $2/README.md) ${1%_nix} Nix"
            local p="$1[@]"
            read -a ${1} <<< $(echo ${!p//$2})
          }

          pushd examples/cc-template
          echo
          echo "::group::Running $(head -n1 README.md) with Nix"
          nix develop --command bazel run //src:hello-world
          popd

          pushd examples/toolchains
          with_nix=( $(ls) )
          without_nix=( cc go java )

          for dir in "${with_nix[@]}"; do
              pushd "$dir"
              echo
              example_name="$(head -n1 README.md) with Nix"
              if [[ -f skip-on-ci ]]; then
                  echo "Skipping $example_name"
                  popd
                  continue
              else
                  echo "::group::Running $example_name"
                  nix-shell --command 'bazel run --config=nix :hello'
                  # TODO: all toolchains should run without Nixpkgs
              fi
              popd
          done
          for dir in "${without_nix[@]}"; do
              pushd "$dir"
              echo
              echo "::group::Running $(head -n1 README.md) without Nix"
              bazel run :hello
              popd
          done

          popd

      - name: Build bazel-nix-python-container with Nix
        uses: tweag/run-nix-shell@v0
        if: ${{ runner.os == 'Linux' }}
        with:
          pure: false
          working-directory: examples/python-container
          run: bazel build :hello_image

      - name: Run bazel-nix-flakes-example with Nix
        uses: tweag/run-nix-shell@v0
        if: ${{ runner.os == 'Linux' }}
        with:
          pure: false
          working-directory: examples/flakes
          run: bazel run --crosstool_top=@nixpkgs_config_cc//:toolchain :hello

  all_ci_tests:
    runs-on: ubuntu-latest
    needs:
      - test-nixpkgs
      - test-examples
    if: ${{ always() }}
    steps:
      - uses: cgrindel/gha_join_jobs@794a2d117251f22607f1aab937d3fd3eaaf9a2f5 # v1
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}