Implement multiplatform builds (#18) (#20)

* Implement multiplatform builds (#18)

* Initial multiplatform build

* Change image name for pr

* Fix prettier errors

* Handle semver

---------

Co-authored-by: Francesco Bruno <f.bruno.dev@gmail.com>

* Avoid dirty version number

* Remove v prefix

* Add tags option

* Fix tags?

---------

Co-authored-by: Francesco Bruno <b.frenc@hotmail.it>
Co-authored-by: Francesco Bruno <f.bruno.dev@gmail.com>

.dockerignore

@@ -1,3 +1,2 @@
 data
 webui/node_modules
-webui/src

.github/workflows/ghcr.yml

@@ -5,19 +5,95 @@ on:
     tags:
       - "v*.*.*"
 
+env:
+  REGISTRY_IMAGE: ghcr.io/bitmagnet-io/bitmagnet
+
 jobs:
-  build-push:
+  build:
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        platform:
+          - linux/amd64
+          - linux/arm/v7
+          - linux/arm64
     steps:
       - name: "Checkout GitHub Action"
         uses: actions/checkout@main
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY_IMAGE }}
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: "Login to GitHub Container Registry"
         uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
-      - name: "Build and push"
+
+      - name: Build and push by digest
+        id: build
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          platforms: ${{ matrix.platform }}
+          labels: ${{ steps.meta.outputs.labels }}
+          outputs: type=image,name=${{ env.REGISTRY_IMAGE }},push-by-digest=true,name-canonical=true,push=true
+
+      - name: Export digest
         run: |
-          docker build . --tag ghcr.io/bitmagnet-io/bitmagnet:${GITHUB_REF#refs/tags/} --tag ghcr.io/bitmagnet-io/bitmagnet:latest
-          docker push --all-tags ghcr.io/bitmagnet-io/bitmagnet
+          mkdir -p /tmp/digests
+          digest="${{ steps.build.outputs.digest }}"
+          touch "/tmp/digests/${digest#sha256:}"
+
+      - name: Upload digest
+        uses: actions/upload-artifact@v3
+        with:
+          name: digests
+          path: /tmp/digests/*
+          if-no-files-found: error
+          retention-days: 1
+
+  merge:
+    runs-on: ubuntu-latest
+    needs:
+      - build
+    steps:
+      - name: Download digests
+        uses: actions/download-artifact@v3
+        with:
+          name: digests
+          path: /tmp/digests
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY_IMAGE }}
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+      - name: "Login to GitHub Container Registry"
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Create manifest list and push
+        working-directory: /tmp/digests
+        run: |
+          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)
+      - name: Inspect image
+        run: |
+          docker buildx imagetools inspect ${{ env.REGISTRY_IMAGE }}:${{ steps.meta.outputs.version }}