ci: Set up mono repo CI for various container images (#1)

.github/workflows/ci.yml

@@ -0,0 +1,36 @@
+name: ci
+
+on:
+  push:
+    branches:
+      - "main"
+  pull_request:
+    branches: [main]
+
+jobs:
+  build_autoconf:
+    name: Build and test
+    strategy:
+      fail-fast: false
+      matrix:
+        autoconf_version: ["2.69", "2.71", "2.72"]
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./autoconf
+    env:
+      TAG: autoconf:${{ matrix.autoconf_version }}-${{ github.run_id }}
+    steps:
+      - name: Checkout Push to Registry action
+        uses: actions/checkout@v4
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Build Dockerfile
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          build-args: AUTOCONF_VERSION=${{ matrix.autoconf_version }}
+          load: true
+          tags: ${{ env.TAG }}
+      - name: Test
+        run: docker run --rm $TAG autoconf --version | grep ${{ matrix.autoconf_version }}