Add Docker image workflow [ci skip]

.github/workflows/docker-image.yml

@@ -0,0 +1,37 @@
+name: docker-image
+
+on:
+  push:
+    branches:
+      - 'master'
+    tags:
+      - 'docker-image'
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Extract version
+        id: get_version
+        run: |
+          echo "::set-output name=VERSION::$(grep -oP 'version = \K.*' setup.cfg)"
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Login to DockerHub
+        uses: docker/login-action@v1 
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: true
+          tags: alexzhangs/shadowsocks-manager:${{ steps.get_version.outputs.VERSION }}
+          platforms: linux/amd64,linux/arm64