feat: add matrix build

.forgejo/workflows/docker-publish-semantic.yml

@@ -20,14 +20,22 @@ env:
   IMAGE_NAME: ${{ github.repository }}
 
 jobs:
-  build-and-push-semantic:
-    runs-on: docker
+  build:
+    runs-on: ${{ matrix.runner }}
     container:
       image: node:lts-bookworm
       options: --privileged
     permissions:
       contents: read
       packages: write
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - platform: linux/amd64
+            runner: docker-amd64
+          - platform: linux/arm64
+            runner: docker-arm64
 
     steps:
       - name: Install Docker
@@ -53,9 +61,6 @@ jobs:
             "https://oauth2:${{ github.token }}@bitfreedom.net/code/${{ github.repository }}.git" \
             .
 
-      - name: Set up QEMU (for multi-arch builds)
-        uses: https://github.com/docker/setup-qemu-action@v3
-
       - name: Set up Docker Buildx
         uses: https://github.com/docker/setup-buildx-action@v3
         with:
@@ -68,29 +73,77 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.REGISTRY_TOKEN }}
 
+      - name: Build and push platform image
+        id: build
+        uses: https://github.com/docker/build-push-action@v6
+        with:
+          context: .
+          platforms: ${{ matrix.platform }}
+          push: true
+          provenance: false
+          build-args: |
+            SEMANTIC_CACHE=true
+          tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache-semantic-${{ matrix.platform == 'linux/amd64' && 'amd64' || 'arm64' }}
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache-semantic-${{ matrix.platform == 'linux/amd64' && 'amd64' || 'arm64' }}
+          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache-semantic-${{ matrix.platform == 'linux/amd64' && 'amd64' || 'arm64' }},mode=max
+
+      - name: Export digest
+        run: |
+          mkdir -p /tmp/digests
+          digest="${{ steps.build.outputs.digest }}"
+          touch "/tmp/digests/${digest#sha256:}"
+
+      - name: Upload digest
+        uses: https://github.com/actions/upload-artifact@v4
+        with:
+          name: digest-semantic-${{ matrix.platform == 'linux/amd64' && 'amd64' || 'arm64' }}
+          path: /tmp/digests/*
+          if-no-files-found: error
+          retention-days: 1
+
+  merge:
+    runs-on: docker-amd64
+    needs: build
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - name: Download digests
+        uses: https://github.com/actions/download-artifact@v4
+        with:
+          path: /tmp/digests
+          pattern: digest-semantic-*
+          merge-multiple: true
+
+      - name: Install Docker
+        run: |
+          apt-get update -qq
+          apt-get install -y -qq docker.io
+
+      - name: Set up Docker Buildx
+        uses: https://github.com/docker/setup-buildx-action@v3
+
+      - name: Log in to Forgejo Container Registry
+        uses: https://github.com/docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
       - name: Extract Docker metadata
         id: meta
         uses: https://github.com/docker/metadata-action@v5
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           tags: |
-            # Versioned semantic tags on git tags (e.g. v0.7.0 → 0.7.0-semantic, 0.7-semantic)
             type=semver,pattern={{version}}-semantic
             type=semver,pattern={{major}}.{{minor}}-semantic
-            # latest-semantic only on main branch pushes
             type=raw,value=latest-semantic,enable=${{ github.ref == 'refs/heads/main' }}
-            # SHA-tagged for traceability
             type=sha,prefix=sha-,suffix=-semantic
 
-      - name: Build and push semantic Docker image
-        uses: https://github.com/docker/build-push-action@v6
-        with:
-          context: .
-          platforms: linux/amd64,linux/arm64
-          push: true
-          build-args: |
-            SEMANTIC_CACHE=true
-          tags: ${{ steps.meta.outputs.tags }}
-          labels: ${{ steps.meta.outputs.labels }}
-          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache-semantic
-          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache-semantic,mode=max
+      - name: Create and push multi-arch manifest
+        working-directory: /tmp/digests
+        run: |
+          docker buildx imagetools create \
+            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            $(printf '${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@sha256:%s ' *)