使用 apache 和 mod_wsgi 部署 Django 站点后的套接字错误？

Question

There is a backend function in my site that will call urllib.urlopen(url)) to retrieve data from url. After deploying, all other functions worked well except this one. Calling this function results in [Errno socket error] [Errno -2] Name or service not known . It seems that it can't find the host.

But if I use python manage.py runserver to run the site, this function works well.

I'm wondering whether maybe there is some problem with Apache, but if there is I can't find it. Thanks for your help.

This is the function:

WORD_URL = 'http://dict.cn/ws.php?utf8=true&q=%s'

def get_word(word):
    url = WORD_URL % word
    dom = minidom.parse(urllib.urlopen(url))
    try:
        pron = dom.getElementsByTagName('pron')[0].firstChild.data
        definition = dom.getElementsByTagName('def')[0].firstChild.data
    except IndexError:
        pron = ''
        definition = ''
    return {
        'word':word,
        'pron':pron,
        'definition':definition
        }

This is the traceback:

Traceback:
File "/usr/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/home/jxq/djcode/wormo/core/views.py" in added
31.             xml_word = get_word(new_word)
File "/home/jxq/djcode/wormo/core/get_word.py" in get_word
8.     dom = minidom.parse(urllib.urlopen(url))
File "/usr/lib/python2.7/urllib.py" in urlopen
84.         return opener.open(url)
File "/usr/lib/python2.7/urllib.py" in open
205.                 return getattr(self, name)(url)
File "/usr/lib/python2.7/urllib.py" in open_http
342.         h.endheaders(data)
File "/usr/lib/python2.7/httplib.py" in endheaders
937.         self._send_output(message_body)
File "/usr/lib/python2.7/httplib.py" in _send_output
797.         self.send(msg)
File "/usr/lib/python2.7/httplib.py" in send
759.                 self.connect()
File "/usr/lib/python2.7/httplib.py" in connect
740.                                              self.timeout, self.source_address)
File "/usr/lib/python2.7/socket.py" in create_connection
553.     for res in getaddrinfo(host, port, 0, SOCK_STREAM):

Exception Type: IOError at /wormo/added/
Exception Value: [Errno socket error] [Errno -2] Name or service not known

httpd.conf:

WSGIScriptAlias / /home/jxq/djcode/wormo/apache/django.wsgi

<Directory /home/jxq/djcode/wormo/apache>
    Order allow,deny
    Allow from all
</Directory>

Alias /media/ /home/jxq/djcode/wormo/media/

<Directory /home/jxq/djcode/wormo>
Order deny,allow
Allow from all
</Directory>

Python 3 and Python 2.7 are both on my machine. Is this a problem?

Answer 1

It's possible that this could be a permission issue or something else with your Apache environment. Try using a simple WSGI script as a baseline to test URL fetching:

import sys
import urllib    

def application(environ, start_response):
   page_text = urllib.urlopen("http://www.google.com/").read()
   start_response('200 OK', [
     ('Content-Type', 'text/html'),
     ('Content-Length', str(len(page_text))),
   ])
   yield page_text