使用GitHub Actions部署Python应用至Azure App Service遇pyodbc缺失问题

问题背景 #

通过GitHub Actions将Python Web应用部署到Azure App Service，应用需连接Azure SQL后端查询数据。已配置secrets.AZURE_WEBAPP_PUBLISH_PROFILE密钥，相关配置如下：

仓库结构

/python-app$
.
├── app
│   ├── app.py
│   ├── requirements.txt
│   ├── static
│   │   └── styles.css
│   └── templates
│       ├── index.html
│       └── welcome.html
├── terraform-infra

原GitHub Actions流水线

name: Build and Deploy Python App to Azure Web App
on:
  push:
    branches:
      - main
  workflow_dispatch:

jobs:
  build:
    runs-on: ubuntu-latest
    
    steps:
      - uses: actions/checkout@v4

      - name: Set up Python version
        uses: actions/setup-python@v5
        with:
          python-version: '3.12'

      - name: Install unixodbc
        run: sudo apt-get install -y unixodbc

      - name: Create and activate virtual environment
        run: |
          python -m venv venv
          source venv/bin/activate
      
      - name: Install dependencies
        run: pip install -r app/requirements.txt
        
      - name: Compress artifact for deployment
        run: zip release.zip ./app/* -r

      - name: Upload artifact for deployment jobs
        uses: actions/upload-artifact@v4
        with:
          name: python-app
          path: |
            release.zip
            !venv/

  deploy:
    runs-on: ubuntu-latest
    needs: build
    environment:
      name: 'Production'
      url: ${{ steps.deploy-to-webapp.outputs.webapp-url }}
    
    steps:
      - name: Download artifact from build job
        uses: actions/download-artifact@v4
        with:
          name: python-app

      - name: Unzip artifact for deployment
        run: |
          unzip release.zip
          mv app/* .

      - name: 'Deploy to Azure Web App'
        uses: azure/webapps-deploy@v3
        id: deploy-to-webapp
        with:
          app-name: 'python-app-mario'
          slot-name: 'production'
          publish-profile: ${{ secrets.AZURE_WEBAPP_PUBLISH_PROFILE }}

requirements.txt内容

bcrypt==4.2.0
blinker==1.8.2
click==8.1.7
Flask==3.0.3
itsdangerous==2.2.0
Jinja2==3.1.4
MarkupSafe==2.1.5
pyodbc==5.1.0
Werkzeug==3.0.4

app.py数据库连接代码

database = os.getenv("database")
password = os.getenv("password")
server = os.getenv("server")
user = os.getenv("user")
driver= '{ODBC Driver 17 for SQL Server}'

# Connecting to SQL server
conexion = pyodbc.connect(f"DRIVER={driver};SERVER={server};DATABASE={database};UID={user};PWD={password}")

错误现象

部署后访问应用出现Application Error，日志显示核心错误：

ModuleNotFoundError: No module named 'pyodbc'

已尝试在构建阶段安装pyodbc和unixodbc，也用过Azure提供的默认流水线，问题未解决。

解决方案 #

通过以下两步修复问题：

1. 调整依赖安装路径
   将依赖安装到应用目录内的.python_packages/lib/site-packages文件夹，确保部署包包含所有Python依赖。修改后的构建阶段依赖安装步骤如下：

- name: Install dependencies
  run: pip install --target="./.python_packages/lib/site-packages" -r requirements.txt
  working-directory: ./app

2. 启用Azure部署时构建
   在Terraform基础设施配置文件中添加环境变量：

SCM_DO_BUILD_DURING_DEPLOYMENT = 1

此配置确保Azure App Service在部署期间执行构建流程，正确识别并加载安装的依赖包。

内容的提问来源于stack exchange，提问作者Mario SFdez