Add GitHub Actions workflow to build and push Docker image

Build multi-arch (amd64/arm64) images to ghcr.io on main, tags, and manual runs.

Author: FX

.github/workflows/docker.yml

@@ -0,0 +1,63 @@
+name: Docker Image
+
+on:
+  push:
+    branches: [main]
+    tags: ["v*"]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  packages: write
+
+concurrency:
+  group: docker-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: Build and push
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository }}
+          tags: |
+            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=sha,prefix=sha-
+            type=ref,event=branch
+
+      - name: Login to GHCR
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

README.md

@@ -36,6 +36,41 @@ docker compose up -d --build
 docker compose down
 ```
 
+## GitHub Actions 镜像
+
+推送到 `main` 或打 `v*` 标签后，会自动构建并推送多架构镜像到 GHCR：
+
+- `ghcr.io/fatelightx/appupdate:latest`（main）
+- `ghcr.io/fatelightx/appupdate:sha-<短提交>`
+- `ghcr.io/fatelightx/appupdate:1.0.0`（标签 `v1.0.0`）
+
+### 使用预构建镜像
+
+```bash
+# 私有仓库镜像需先登录（用有 read:packages 的 Token）
+echo YOUR_GITHUB_TOKEN | docker login ghcr.io -u FateLightX --password-stdin
+
+docker pull ghcr.io/fatelightx/appupdate:latest
+
+docker run -d --name appupdate \
+  -p 8000:8000 \
+  -v "$PWD/data:/data" \
+  --restart unless-stopped \
+  ghcr.io/fatelightx/appupdate:latest
+```
+
+或在 `docker-compose.yml` 中注释 `build`，启用：
+
+```yaml
+image: ghcr.io/fatelightx/appupdate:latest
+```
+
+工作流文件：`.github/workflows/docker.yml`  
+也可在 GitHub → Actions → **Docker Image** → **Run workflow** 手动触发。
+
+若镜像拉不下来：到仓库 **Packages** 将 `appupdate` 包设为 Public，或保持 Private 并用 Token 登录。
+
+
 ## 可选环境变量
 
 | 变量 | 说明 |

docker-compose.yml

@@ -1,6 +1,9 @@
 services:
   appupdate:
+    # 本地构建：
     build: .
+    # 或使用 GitHub Actions 推送的镜像（二选一，使用镜像时注释掉 build）：
+    # image: ghcr.io/fatelightx/appupdate:latest
     container_name: appupdate
     ports:
       - "8000:8000"