docker容器内的Python，优雅地停止

我正在运行一个非常基本的 Python 循环示例Windows docker 容器，我愿意优雅地停下来.

该脚本在我的 dockerfile 中以这种方式启动：

CMD [“python.exe”，“./test.py”]

在 docker 文档中说SIGTERM 信号已发送到主命令，所以我试图这样捕捉它：

import signal
import time
import logging, sys

class GracefulKiller:
  kill_now = False
  def __init__(self):
    signal.signal(signal.SIGINT, self.exit_gracefully)
    signal.signal(signal.SIGTERM, self.exit_gracefully)

  def exit_gracefully(self,signum, frame):
    self.kill_now = True

if __name__ == '__main__':
  logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)
  killer = GracefulKiller()
  while True:
    time.sleep(1)
    logging.info("doing something in a loop ...")
    if killer.kill_now:
      break

  logging.info("End of the program. I was killed gracefully :)")

理论上，信号应该被处理程序捕获，布尔值应该切换，循环应该退出并显示我的最后一个日志行。事实并非如此，它只是在发出信号时（或者 2-3 秒后）停止整个事情

C:\Users\Administrator\Documents\Projects\test>docker-compose up
Recreating test_1 ... done
Attaching to test_1
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
test_1  | INFO:root:doing something in a loop ...
Gracefully stopping... (press Ctrl+C again to force)
Stopping test_1   ... done

我的最后一行日志从未到达。 有谁知道发生了什么事吗？这是 python 特定问题、docker 特定问题还是 Windows 特定问题？

我还尝试使用 docker 日志检查已停止的容器，最后一个日志也不在这里。尝试在其后添加睡眠，结果相同。

Thanks,

这在使用时似乎仍然普遍存在docker-compose up在当前版本中，我整个早上都在 Raspbian 上进行调查（并引导我来到这里）。

但是运行你的例子docker-compose 2.1.1 via docker-compose up使用以下配置显示您的 python 代码的最后一行实际上被调用，您只是看不到它：

docker-compose.yaml

services:
  grace_test:
    container_name: grace_test
    build: .

Dockerfile

FROM python:3.8-slim-buster

# setup WORKDIR
ADD . /grace_test
WORKDIR /grace_test
CMD ["python", "test.py"]

test.py

import signal
import time
import logging, sys

class GracefulKiller:
  kill_now = False
  def __init__(self):
    signal.signal(signal.SIGINT, self.exit_gracefully)
    signal.signal(signal.SIGTERM, self.exit_gracefully)

  def exit_gracefully(self,signum, frame):
    self.kill_now = True

if __name__ == '__main__':
  logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)
  killer = GracefulKiller()
  while True:
    time.sleep(1)
    logging.info("doing something in a loop ...")
    if killer.kill_now:
      break

  logging.info("End of the program. I was killed gracefully :)")

Verify

Use docker-compose logs之后检查日志Ctrl-C:

$ docker-compose logs
grace_test  | INFO:root:doing something in a loop ...
grace_test  | INFO:root:doing something in a loop ...
grace_test  | INFO:root:doing something in a loop ...
grace_test  | INFO:root:doing something in a loop ...
grace_test  | INFO:root:End of the program. I was killed gracefully :)