python - 基于 Docker 的环境配置中带有 mod_wsgi 的 Apache

Question

我需要设置:WSGIRestrictSignal Off，因为一旦调用正常关闭，我必须在 python 代码中执行一些操作。

来自文档:

行为良好的 Python WSGI 应用程序通常不应使用 signal.signal() 注册其自己的任何信号处理程序。原因是托管 WSGI 应用程序的 Web 服务器很可能会注册自己的信号处理程序。如果 WSGI 应用程序要覆盖此类信号处理程序，它可能会干扰 Web 服务器的操作，从而阻止服务器关闭和重新启动等操作。

你知道如何更改Docker中的配置文件吗？
我应该覆盖现有文件吗？

这是我的 Dockerfile:

FROM grahamdumpleton/mod-wsgi-docker:python-2.7
ADD requirements.txt requirements.txt
RUN ["pip", "install", "-r", "requirements.txt"]

WORKDIR /app
COPY src/main/scripts/app.wsgi /app/app.wsgi

ENTRYPOINT [ "mod_wsgi-docker-start" ]

CMD [ "app.wsgi", "--processes", "1", "--port", "5000" ]

我应该放这样的东西吗？

ADD "httpd.conf" /tmp/mod_wsgi-localhost:5000:0/httpd.conf

据我所知，mod_wsgi-docker-start”正在通过选择“默认”配置来执行所有操作。

由于 WSGIRestrictSignal 设置为“默认”，因此如果引发信号则无法捕获信号:

Server URL         : http://localhost:5000/
Server Root        : /tmp/mod_wsgi-localhost:5000:0
Server Conf        : /tmp/mod_wsgi-localhost:5000:0/httpd.conf
Error Log File     : /dev/stderr (warn)
Startup Log File   : /dev/stderr
Request Capacity   : 5 (1 process * 5 threads)
Request Timeout    : 60 (seconds)
Startup Timeout    : 15 (seconds)
Queue Backlog      : 100 (connections)
Queue Timeout      : 45 (seconds)
Server Capacity    : 20 (event/worker), 20 (prefork)
Server Backlog     : 500 (connections)
Locale Setting     : en_US.UTF-8
[Wed Sep 06 09:37:32.673894 2017] [mpm_event:notice] [pid 14:tid 140686654945024] AH00489: Apache/2.4.25 (Unix) mod_wsgi/4.5.7 Python/2.7 configured -- resuming normal operations
[Wed Sep 06 09:37:32.674133 2017] [core:notice] [pid 14:tid 140686654945024] AH00094: Command line: 'httpd (mod_wsgi-express) -f /tmp/mod_wsgi-localhost:5000:0/httpd.conf -E /dev/stderr -D MOD_WSGI_MULTIPROCESS -D MOD_WSGI_MPM_ENABLE_EVENT_MODULE -D MOD_WSGI_MPM_EXISTS_EVENT_MODULE -D MOD_WSGI_MPM_EXISTS_WORKER_MODULE -D MOD_WSGI_MPM_EXISTS_PREFORK_MODULE -D FOREGROUND'
^C[Wed Sep 06 09:37:33.106471 2017] [mpm_event:notice] [pid 14:tid 140686654945024] AH00491: caught SIGTERM, shutting down
[Wed Sep 06 09:37:33.254507 2017] [wsgi:warn] [pid 16:tid 140686654945024] mod_wsgi (pid=16): Callback registration for signal 28 ignored.
[Wed Sep 06 09:37:33.256509 2017] [wsgi:warn] [pid 16:tid 140686654945024]   File "/tmp/mod_wsgi-localhost:5000:0/handler.wsgi", line 94, in <module>
[Wed Sep 06 09:37:33.256546 2017] [wsgi:warn] [pid 16:tid 140686654945024]     recorder_directory=recorder_directory)
[Wed Sep 06 09:37:33.256563 2017] [wsgi:warn] [pid 16:tid 140686654945024]   File "/usr/local/python/lib/python2.7/site-packages/mod_wsgi/server/__init__.py", line 1355, in __init__
[Wed Sep 06 09:37:33.256642 2017] [wsgi:warn] [pid 16:tid 140686654945024]     exec(code, self.module.__dict__)
[Wed Sep 06 09:37:33.256720 2017] [wsgi:warn] [pid 16:tid 140686654945024]   File "/app/myapp.py", line 325, in <module>
[Wed Sep 06 09:37:33.256770 2017] [wsgi:warn] [pid 16:tid 140686654945024]     signal.signal(signal.SIGWINCH, on_exit)

即使我解决了以下问题，官方文档中的信息仍然困扰着我:

Do note that if enabling the ability to register signal handlers, such a registration can only reliably be done from within code which is implemented as a side effect of importing a script file identified by the WSGIImportScript directive. This is because signal handlers can only be registered from the main Python interpreter thread, and request handlers when using embedded mode and a multithreaded Apache MPM would generally execute from secondary threads. Similarly, when using daemon mode, request handlers would executed from secondary threads. Only code run as a side effect of WSGIImportScript is guaranteed to be executed in main Python interpreter thread.

Answer 1

不要使用信号。使用 Python 中的 atexit 模块来注册回调。当进程关闭时，回调将被调用。