Gunicorn应用在GAE上异常：静态文件正常但接口请求返回503错误

• 静态文件能正常访问，但配置的entrypoint完全未执行；曾尝试将start.sh设为entrypoint并添加echo "Starting gunicorn"语句，日志中无任何相关输出
• 本地测试代码无问题，未使用Gunicorn时应用可正常运行
• 预期API接口与静态前端均能正常工作，但目前仅静态文件可用

原app.yaml配置 #

runtime: python39
entrypoint: gunicorn --worker-class eventlet -t 4 -w 1 --timeout 120 main:app -b :$PORT

manual_scaling:
  instances: 1

network:
  session_affinity: true

handlers:
  # API handlers
  - url: /api/.*
    script: auto
    secure: always
    redirect_http_response_code: 301

  # Static file handlers
  - url: /(.*\.(html|css|js|png|jpg|jpeg|gif|ico|json|webp|svg))
    static_files: frontend/dist/\1
    upload: frontend/dist/(.*\.(html|css|js|png|jpg|jpeg|gif|ico|json|webp|svg))
    secure: always

  # Catch-all handler for other static files and single-page app support
  - url: /.*
    static_files: frontend/dist/index.html
    upload: frontend/dist/index.html
    secure: always

解决方法 #

问题出在路由处理逻辑上，改为在Python应用中托管静态文件。针对单页应用（SPA），添加如下路由处理代码：

# Catch-all for SPA
@app.route('/', defaults={'path': ''})
@app.route('/<path:path>')
def catch_all(path):
    if re.match("(.*\.(html|css|js|png|jpg|jpeg|gif|ico|json|webp|svg))", path):
        return app.send_static_file(path)
    return app.send_static_file("index.html")

内容的提问来源于stack exchange，提问作者Lukas Dobbles