从 Flask 项目打包为多平台 Docker 镜像并上传 Docker Hub（含 GitHub Actions

🧱 1. 创建一个基础 Flask 项目

项目结构：

flask-demo/
├── app.py
├── requirements.txt
├── Dockerfile
├── start.sh
└── .github/
  └── workflows/
      └── docker.yml

app.py

from flask import Flask
app = Flask(name)
​
@app.route(‘/‘)
def hello():
   return “Hello from multi-arch Flask Docker in production mode!”

requirements.txt

flask
gunicorn

start.sh

#!/bin/bash

start.sh

​

默认使用 4 个 Gunicorn worker

WORKERS=${WORKERS:-4}
​
echo “🚀 Starting Gunicorn with $WORKERS workers…”
​

启动 Flask 应用

exec gunicorn -w “$WORKERS” -b 0.0.0.0:5000 app:app
​

---

🐋 2. 编写多平台 Dockerfile

FROM python:3.12-slim
​
WORKDIR /app
​
COPY requirements.txt .
RUN pip install –no-cache-dir -r requirements.txt
​
COPY . .
​
RUN chmod +x start.sh
​
CMD [“./start.sh”]

---

⚙️ 3. 本地构建 & 推送多平台镜像（可选）

#!/bin/bash
​
set -e
​

==== 配置区域 ====

IMAGE_NAME=”cloudsmithy/flask-demo”             # Docker Hub 镜像名
PLATFORMS=”linux/amd64,linux/arm64”             # 多架构支持
BUILDER_NAME=”multiarch”                        # buildx 构建器名

==================

​

获取 TAG，优先使用 Git tag，其次 fallback 为时间戳

TAG=$(git describe –tags –abbrev=0 2>/dev/null || date +%Y%m%d)
​
echo “🔖 使用镜像 tag：$TAG”
echo “📦 构建并推送镜像：”
echo “ - $IMAGE_NAME:$TAG”
echo “ - $IMAGE_NAME:latest”
​

登录 Docker Hub（如果没有缓存登录状态）

if ! docker info | grep -q “Username: cloudsmithy”; then
 echo “🔐 正在登录 Docker Hub…”
docker login -u cloudsmithy
fi
​

创建 buildx builder（如不存在）

if ! docker buildx inspect “$BUILDER_NAME” &> /dev/null; then
docker buildx create –name “$BUILDER_NAME” –use
else
docker buildx use “$BUILDER_NAME”
fi
​
docker buildx inspect –bootstrap
​

构建并推送镜像

docker buildx build –platform “$PLATFORMS” \
 -t “$IMAGE_NAME:$TAG” \
 -t “$IMAGE_NAME:latest” \
 –push .
​

---

🚀 4. 设置 GitHub Actions 自动推送镜像

在 .github/workflows/docker.yml 中创建以下内容：

name: Build and Push Docker Image
​
on:
push:
  tags:
    - ‘v*‘  # 仅在 tag push（如 v1.0.0）时触发
​
jobs:
build-and-push:
  runs-on: ubuntu-latest
​
  steps:
  - name: Checkout source code
    uses: actions/checkout@v4
​
  - name: Check DockerHub secrets
    run: |
      if [ -z “$“ ] || [ -z “$“ ]; then
        echo “❌ ERROR: DOCKER_USERNAME or DOCKER_PASSWORD is missing”
        exit 1
      fi
​
  - name: Set up QEMU
    uses: docker/setup-qemu-action@v3
​
  - name: Set up Docker Buildx
    uses: docker/setup-buildx-action@v3
    with:
      install: true  # ✅ 自动创建默认 builder
​
  - name: Docker login
    uses: docker/login-action@v3
    with:
      username: $
      password: $
​
  - name: Extract tag name
    id: vars
    run: echo “TAG=${GITHUB_REF#refs/tags/}” >> $GITHUB_ENV
​
  - name: Build and push Docker image (multi-arch + latest)
    uses: docker/build-push-action@v5
    with:
      context: .
      push: true
      platforms: linux/amd64,linux/arm64
      tags: |
        cloudsmithy/flask-demo:$
        cloudsmithy/flask-demo:latest
​

---

🔐 5. 配置 GitHub Secrets

在仓库的 Settings → Secrets → Actions 中添加：

Name	Value
DOCKER_USERNAME	你的 Docker Hub 用户名
DOCKER_PASSWORD	你的 Docker Hub Token（推荐）

---

🏁 6. 触发构建 & 发布流程

git tag v1.0.0
git push origin v1.0.0

GitHub Actions 会自动：

1. 构建支持 x86 + ARM 的镜像

2. 推送到 Docker Hub：

   • cloudsmithy/flask-demo:v1.0.0
   • cloudsmithy/flask-demo:latest

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✅ 7. 结果验证

docker pull cloudsmithy/flask-demo:latest
docker run -p 5000:5000 cloudsmithy/flask-demo:latest

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