Add buildx GH action for multi-arch docker images

.github/workflows/buildx.yaml

@@ -0,0 +1,61 @@
+name: buildx
+
+on:
+  push:
+    branches: master
+    tags:
+      - v*
+
+jobs:
+  buildx:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+      -
+        name: Prepare
+        id: prepare
+        run: |
+          DOCKER_IMAGE=crazymax/diun
+          DOCKER_PLATFORMS=linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/386
+          VERSION=version-${GITHUB_REF#refs/tags/v}
+          TAGS="--tag ${DOCKER_IMAGE}:${VERSION} --tag ${DOCKER_IMAGE}:latest"
+
+          echo ::set-output name=docker_image::${DOCKER_IMAGE}
+          echo ::set-output name=version::${VERSION}
+          echo ::set-output name=buildx_args::--platform ${DOCKER_PLATFORMS} \
+            --build-arg VERSION=${VERSION} \
+            --build-arg BUILD_DATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ') \
+            --build-arg VCS_REF=${GITHUB_SHA::8} \
+            ${TAGS} --file ./test/Dockerfile ./test
+      -
+        name: Set up Docker Buildx
+        uses: crazy-max/ghaction-docker-buildx@v3
+      -
+        name: Docker Buildx (build)
+        run: |
+          docker buildx build --output "type=image,push=false" ${{ steps.prepare.outputs.buildx_args }}
+      -
+        name: Docker Login
+        if: success()
+        env:
+          DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+          DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
+        run: |
+          echo "${DOCKER_PASSWORD}" | docker login --username "${DOCKER_USERNAME}" --password-stdin
+      -
+        name: Docker Buildx (push)
+        if: success()
+        run: |
+          docker buildx build --output "type=image,push=true" ${{ steps.prepare.outputs.buildx_args }}
+      -
+        name: Docker Check Manifest
+        if: always()
+        run: |
+          docker run --rm mplatform/mquery ${{ steps.prepare.outputs.docker_image }}:${{ steps.prepare.outputs.version }}
+      -
+        name: Clear
+        if: always()
+        run: |
+          rm -f ${HOME}/.docker/config.json