Collectives™ on Stack Overflow

Find centralized, trusted content and collaborate around the technologies you use most.

Teams

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

My django application that used to make some shell commands by using python subprocess.Popen does not work anymore since I upgrade to ubuntu to 11.10

To simplify the problem, I put the faulty code into the wsgi script :

import os
import sys
from subprocess import Popen,PIPE
p=Popen(['/usr/bin/id'],stdout=PIPE,stderr=PIPE)
comm=p.communicate()
print comm,p.returncode
os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'
import django.core.handlers.wsgi
application = django.core.handlers.wsgi.WSGIHandler()
If I run this code directly by python, it works :
$ python -V
Python 2.7.2+
$ python django_wsgi.py 
('uid=1002(www) gid=1002(www) groups=1002(www)\n', '') 0
If I run this code by apache (I just put the relevant URL into a browser), in the apache log, I got :
[Tue Nov 29 11:34:38 2011] [error] ('', '') -6
What is this error '-6' ???
The problem is that with my development server (Ubuntu 10.04, almost the same apache/wsgi version, same apache configuration file, same environment variables, but with python 2.6.5) it works well :
[Tue Nov 29 11:29:10 2011] [error] ('uid=1000(www) gid=1000(www) groups=1000(www)\\n', '') 0
Do you know why Popen is not work through apache anymore with python 2.7 ?
Because latest Python 2.7 has a bug in it which causes fork run in sub interpreters to fail.
http://bugs.python.org/issue13156
Presuming only hosting the one WSGI application, force use of the main interpreter rather than a sub interpreter by adding to your Apache configuration:
WSGIApplicationGroup %{GLOBAL}
                The answers says what the workaround is. Force the use of the main interpreter for that web application using the WSGIApplicationGroup directive. That Python bug also has a patch against if which you could also use to patch Python source code and install a new Python installation and use it.
– Graham Dumpleton
                Jan 21, 2012 at 8:17
                I think it helps to know that the patch you need is: hg.python.org/cpython/rev/ee4fe16d9b48
– Darioush
                Jan 25, 2012 at 18:39
        
Thanks for contributing an answer to Stack Overflow!
Please be sure to answer the question. Provide details and share your research!
But avoid …
Asking for help, clarification, or responding to other answers.
Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.