chore: add docker workflow

.github/workflows/docker.yaml

@@ -0,0 +1,59 @@
+name: Docker
+
+on:
+  push:
+    tags: [ 'alpha' ]
+  workflow_dispatch:
+
+env:
+  REGISTRY: docker.io
+  IMAGE_NAME: '{{ env.DOCKERHUB_ACCOUNT }}/{{ env.DOCKERHUB_REPO }}'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Setup Docker buildx
+        uses: docker/setup-buildx-action@v1
+
+      # Extract metadata (tags, labels) for Docker
+      # https://github.com/docker/metadata-action
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Log into registry ${{ env.REGISTRY }}
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      # Build and push Docker image with Buildx (don't push on PR)
+      # https://github.com/docker/build-push-action
+      - name: Build and push Docker image
+        id: build-and-push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          platforms: |
+            linux/386
+            linux/amd64
+            linux/arm64/v8
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}