update github workflow to build multi architecture container images

Author: jcgruenhage

.github/workflows/docker.yml

@@ -1,56 +1,82 @@
 name: Docker build and release
 
 on:
-  release:
-    types: [published]
   push:
-    branches: [master,develop]
+  pull_request:
 
 jobs:
-  deploy_image:
-    name: 'Publish: DockerHub'
-    runs-on: ubuntu-latest
-    if: github.event_name == 'release' || github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/master'
+  build:
+    name: 'Build container image'
+    runs-on: ${{ matrix.platform == 'linux/arm64' && 'ubuntu-24.04-arm' || 'ubuntu-24.04' }}
+    outputs:
+      digest_arm64: ${{ steps.export_digest.outputs.digest_arm64 }}
+      digest_amd64: ${{ steps.export_digest.outputs.digest_amd64 }}
+    strategy:
+      matrix:
+        platform:
+          - linux/amd64
+          - linux/arm64
     steps:
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v1
+      - uses: actions/checkout@v4
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: "ghcr.io/${{ github.repository }}"
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
 
-      - name: Extract branch name
-        shell: bash
-        run: echo "##[set-output name=branch;]$(echo ${GITHUB_REF#refs/heads/})"
-        id: extract_branch
-
-      - name: Generating release tags and labels
-        if: github.event_name == 'release'
-        id: release_meta
-        uses: docker/metadata-action@v4
-        with:
-          images: jaedb/snapserver
-          tags: |
-            latest
-            type=semver,pattern={{version}}
-            type=semver,pattern={{major}}.{{minor}}
-
-      - name: Generating edge branch labels
-        if: github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/master'
-        id: edge_meta
-        uses: docker/metadata-action@v4
+      - name: Build and push by digest
+        id: build
+        uses: docker/build-push-action@v6
         with:
-          images: jaedb/snapserver
-          tags: ${{ steps.extract_branch.outputs.branch }}
+          platforms: ${{ matrix.platform }}
+          labels: ${{ steps.meta.outputs.labels }}
+          outputs: type=image,name=ghcr.io/${{ github.repository }},push-by-digest=true,name-canonical=true,push=true
 
-      - name: Login to DockerHub
-        uses: docker/login-action@v1 
+      - name: Export digest
+        id: export_digest
+        run: |
+          arch="$(echo -n ${{ matrix.platform }} | sed -e 's/linux\///')"
+          digest="${{ steps.build.outputs.digest }}"
+          echo "digest_${arch}=${digest#sha256:}" >> "$GITHUB_OUTPUT"
+
+  merge:
+    runs-on: "ubuntu-24.04"
+    needs:
+      - build
+    steps:
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
         with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
+          images: ghcr.io/${{ github.repository }}
 
-      - name: Build and push
-        uses: docker/build-push-action@v2
+      - name: Login to GHCR
+        uses: docker/login-action@v3
         with:
-          push: true
-          tags: ${{ steps.release_meta.outputs.tags || steps.edge_meta.outputs.tags }}
-          labels: ${{ steps.release_meta.outputs.labels || steps.edge_meta.outputs.tags }}
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Create manifest list and push
+        run: |
+          docker buildx imagetools create \
+            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            ${{ env.DOCKERHUB_REPO }}@sha256:${{ needs.build.outputs.digest_arm64 }} \
+            ${{ env.DOCKERHUB_REPO }}@sha256:${{ needs.build.outputs.digest_amd64 }}
+
+      - name: Inspect image
+        run: docker buildx imagetools inspect ${{ env.DOCKERHUB_REPO }}:${{ steps.meta.outputs.version }}