尝试导入python模块时的疯狂行为

Question

我想用Apache mod-wsgi部署的django webapp有一些问题，我已经将它们追溯到这一行（django标记模块丢失）：

[Wed Feb 20 13:08:42 2013] [error] [client 172.19.130.50] ImportError: No module named tagging

现在，当我尝试以root和apache用户身份运行pip-python（我使用的是CENTOS 6）时，这里是我的输出：

[root@app1 site-packages]# pip-python freeze | grep tag
django-tagging==0.3.1
django-taggit==0.9.3

已安装标记。。。

[root@app1 site-packages]# sudo -u apache pip-python freeze | grep tag
django-tagging==0.3.1
django-taggit==0.9.3

Apache用户也这么说！

[root@app1 /]# python
Python 2.6.6 (r266:84292, Sep 11 2012, 08:34:23)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import tagging
>>>

确定根可以导入标记！

[root@app1 /]# sudo -u apache python
Python 2.6.6 (r266:84292, Sep 11 2012, 08:34:23)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import tagging
Traceback (most recent call last):
  File "", line 1, in 
ImportError: No module named tagging
>>>

但是apache用户不能！！！！！我如何才能使这项工作？？？？

我已经对django tagging/usr/lib/python2.6/site-packages/的所有权限进行了双重和三重检查，它们与我的其他软件包相同。

更新1:我真的不记得我是如何安装django标记模块的，但可能是作为root用户安装的，因为apache无法全局安装模块！

更新2:以下是martijn pieters建议的输出：

[root@app1 /]# sudo -u apache python -c 'import sys; print sys.path'
['', '/usr/lib64/python2.6/site-packages/Twisted-12.1.0-py2.6-linux-x86_64.egg', '/usr/lib/python2.6/site-packages/django_cas-2.1.1-py2.6.egg', '/usr/lib64/python26.zip', '/usr/lib64/python2.6', '/usr/lib64/python2.6/plat-linux2', '/usr/lib64/python2.6/lib-tk', '/usr/lib64/python2.6/lib-old', '/usr/lib64/python2.6/lib-dynload', '/usr/lib64/python2.6/site-packages', '/usr/lib/python2.6/site-packages', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info']
[root@app1 /]# python -c 'import sys; print sys.path'
['', '/usr/lib64/python2.6/site-packages/Twisted-12.1.0-py2.6-linux-x86_64.egg', '/usr/lib/python2.6/site-packages/django_cas-2.1.1-py2.6.egg', '/usr/lib64/python26.zip', '/usr/lib64/python2.6', '/usr/lib64/python2.6/plat-linux2', '/usr/lib64/python2.6/lib-tk', '/usr/lib64/python2.6/lib-old', '/usr/lib64/python2.6/lib-dynload', '/usr/lib64/python2.6/site-packages', '/usr/lib/python2.6/site-packages', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info']
[root@app1 /]# sudo -u apache head `which pip-python`
#!/usr/bin/python
# EASY-INSTALL-ENTRY-SCRIPT: 'pip==0.8','console_scripts','pip'
__requires__ = 'pip==0.8'
import sys
from pkg_resources import load_entry_point

if __name__ == '__main__':
    sys.exit(
        load_entry_point('pip==0.8', 'console_scripts', 'pip')()
    )
[root@app1 /]# head `which pip-python`
#!/usr/bin/python
# EASY-INSTALL-ENTRY-SCRIPT: 'pip==0.8','console_scripts','pip'
__requires__ = 'pip==0.8'
import sys
from pkg_resources import load_entry_point

if __name__ == '__main__':
    sys.exit(
        load_entry_point('pip==0.8', 'console_scripts', 'pip')()
    )

是完全相同的：（

更新3:是，apache用户可以加载其他模块：

[root@app1 /]# sudo -u apache python
Python 2.6.6 (r266:84292, Sep 11 2012, 08:34:23)
[GCC 4.4.6 20120305 (Red Hat 4.4.6-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> import twisted
>>> import cairo

更新4：我恨我自己。问题是 /usr/lib/python2.6/site-packages/tagging/目录的访问权限！它们是drw-r--r--（644）而不是正确的drwxr-xr-x（755），因此apache用户无法进入目录：（

现在一切正常，谢谢你的帮助！

Answer 1

我经历过类似的行为，并最终将要导入的模块的确切路径添加到Django wsgi.py文件中：

import sys
PACKAGES ='/usr/local/lib/python2.6/dist-packages/'
sys.path.append(PACKAGES + 'django_compressor-1.1.1-py2.6.egg')

希望能有帮助。

谁该受责备？不确定，可能是apache或mod_wsgi。这在Ubuntu 10.04的apache2中发生在我身上。Debian stable和testing最近在apache2中的设置不再需要sys.path.append。