Add Github workflows with multiarch builds using docker buildx

.github/workflows/ci.yml

@@ -0,0 +1,117 @@
+name: ci
+on:
+  push:
+    branches:
+    - master
+    tags:
+    - '**'
+  pull_request:
+    branches:
+    - master
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+
+    # See: https://github.com/docker/build-push-action/blob/v2.6.1/docs/advanced/cache.md#github-cache
+    - name: Set up QEMU
+      uses: docker/setup-qemu-action@v2
+
+    - name: Set up Docker Buildx
+      id: buildx
+      uses: docker/setup-buildx-action@master
+
+    - name: Cache Docker layers
+      uses: actions/cache@v3
+      with:
+        path: /tmp/.buildx-cache
+        key: ${{ runner.os }}-buildx-${{ github.sha }}
+        restore-keys: |
+          ${{ runner.os }}-buildx-
+
+    - name: Prepare
+      id: prep
+      run: |
+        set -e
+
+        # Get ref, i.e. <branch_name> from refs/heads/<branch_name>, or <tag-name> from refs/tags/<tag_name>. E.g. 'master' or 'v1.2.3'
+        REF=$( echo "${GITHUB_REF}" | rev | cut -d '/' -f 1 | rev )
+
+        # Get commit hash E.g. 'b29758a'
+        SHA_SHORT=$( echo "${GITHUB_SHA}" | cut -c1-7 )
+
+        # Pass variables to next step
+        echo "REF=$REF" >> $GITHUB_ENV
+        echo "SHA_SHORT=$SHA_SHORT" >> $GITHUB_ENV
+
+    - name: Login to docker registry
+      if: github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/')
+      run: echo "${DOCKERHUB_REGISTRY_PASSWORD}" | docker login -u "${DOCKERHUB_REGISTRY_USER}" --password-stdin
+      env:
+        DOCKERHUB_REGISTRY_USER: ${{ secrets.DOCKERHUB_REGISTRY_USER }}
+        DOCKERHUB_REGISTRY_PASSWORD: ${{ secrets.DOCKERHUB_REGISTRY_PASSWORD }}
+
+    - name: Build (PRs)
+      id: docker_build_pr
+      # Run only on pull requests
+      if: github.event_name == 'pull_request'
+      uses: docker/build-push-action@v3
+      with:
+        context: '.'
+        file: ./.docker/release/Dockerfile
+        platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/s390x
+        push: true
+        tags: |
+          ${{ github.repository }}:${{ env.REF }}
+          ${{ github.repository }}:${{ env.REF }}-${{ env.SHA_SHORT }}
+        cache-from: type=local,src=/tmp/.buildx-cache
+        cache-to: type=local,dest=/tmp/.buildx-cache-new,mode=max
+
+    - name: Build and push (master)
+      id: docker_build_master
+      # Run only on master
+      if: github.ref == 'refs/heads/master'
+      uses: docker/build-push-action@v3
+      with:
+        context: '.'
+        file: ./.docker/release/Dockerfile
+        platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/s390x
+        push: true
+        tags: |
+          ${{ github.repository }}:${{ env.REF }}
+          ${{ github.repository }}:${{ env.REF }}-${{ env.SHA_SHORT }}
+        cache-from: type=local,src=/tmp/.buildx-cache
+        cache-to: type=local,dest=/tmp/.buildx-cache-new,mode=max
+
+    - name: Build and push (release)
+      id: docker_build_release
+      if: startsWith(github.ref, 'refs/tags/')
+      uses: docker/build-push-action@v3
+      with:
+        context: '.'
+        file: ./.docker/release/Dockerfile
+        platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/s390x
+        push: true
+        tags: |
+          ${{ github.repository }}:${{ env.REF }}
+          ${{ github.repository }}:${{ env.REF }}-${{ env.SHA_SHORT }}
+          ${{ github.repository }}:latest
+        cache-from: type=local,src=/tmp/.buildx-cache
+        cache-to: type=local,dest=/tmp/.buildx-cache-new,mode=max
+
+    # Temp fix
+    # https://github.com/docker/build-push-action/issues/252
+    # https://github.com/moby/buildkit/issues/1896
+    - name: Move cache
+      run: |
+        rm -rf /tmp/.buildx-cache
+        mv /tmp/.buildx-cache-new /tmp/.buildx-cache
+
+    - name: List docker images
+      run: docker images
+
+    - name: Clean-up
+      run: docker logout
+      if: always()