更新烧瓶上的浏览器缓存

Question

我有一个小型烧瓶服务器，主要用于试验和开发自用工具（在我的家庭网络上）。它在树莓派机器上以开发模式运行。它被配置为通过rc.local启动时启动：

sudo -H -u pi /home/pi/Server/start.sh &

start.sh 文件读取

#!/bin/bash

cd /home/pi/Server
source /home/pi/Server/venv/bin/activate
export FLASK_APP=/home/pi/Server/app.py
export FLASK_ENV=development
export FLASK_RUN_HOST=192.168.1.104
export FLASK_RUN_PORT=5001

flask run

最初几天一切正常，但现在我收到以下错误：

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/flask/app.py", line 2309, in __call__
    return self.wsgi_app(environ, start_response)
  File "/usr/lib/python3/dist-packages/flask/app.py", line 2295, in wsgi_app
    response = self.handle_exception(e)
  File "/usr/lib/python3/dist-packages/flask/app.py", line 1741, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/lib/python3/dist-packages/flask/_compat.py", line 35, in reraise
    raise value
  File "/usr/lib/python3/dist-packages/flask/app.py", line 2291, in wsgi_app
    ctx.push()
  File "/usr/lib/python3/dist-packages/flask/ctx.py", line 377, in push
    self.app, self.request
  File "/usr/lib/python3/dist-packages/flask/sessions.py", line 343, in open_session
    data = s.loads(val, max_age=max_age)
  File "/usr/lib/python3/dist-packages/itsdangerous.py", line 643, in loads
    .unsign(s, max_age, return_timestamp=True)
  File "/usr/lib/python3/dist-packages/itsdangerous.py", line 466, in unsign
    return value, self.timestamp_to_datetime(timestamp)
  File "/usr/lib/python3/dist-packages/itsdangerous.py", line 404, in timestamp_to_datetime
    return datetime.utcfromtimestamp(ts + EPOCH)
OverflowError: timestamp out of range for platform time_t

据我所知here 这是浏览器缓存的问题。我怎样才能告诉烧瓶来处理这个？

Answer 1

看起来您正在使用会话/cookie？尝试调查一下，也许日期不正确或无效。尝试清除它session.clear() 或使用更短的到期日期。从 python 2 升级到 3 后，我也遇到了一些问题，这会弄乱 cookie，如果你这样做了，你需要清除缓存，以便可以设置 python3 日期/时间 cookie。

Answer 2

当从 Adafruit CircuitPython NTP issue 返回的时间为 0 时，这似乎是一个错误。一种直接的方法是使用 PR 修补一些烧瓶依赖项。

但是，这似乎更多是您的缓存年龄错误。尽量缩短时间

@app.after_request
def after_request(response):
    response.headers["Cache-Control"] = "max-age=300" # in second
    return response