我尝试在nginx+uwsgi上为django设置web服务器，操作系统为debian（3.1.0-1-amd64 x86_64）。 nginx版本为1.1.8-1，uwsgi版本为0.9.8.3-1。 配置如下：
<uwsgi>
<socket>/tmp/uwsgi.sock</socket>
<process>1</process>
<master/>
<enable-threads/>
<uid>33</uid>
<gid>33</gid>
<pidfile>/tmp/uwsgi.pid</pidfile>
</uwsgi>
在文件 /etc/uwsgi/apps-enabled/webapp.xml 中， 涉及到 Nginx 配置。
location / {
uwsgi_pass unix:///tmp/uwsgi.sock;
include uwsgi_params;
uwsgi_param UWSGI_SCRIPT webapp;
uwsgi_param UWSGI_CHDIR /data/web/webapp/webapp;
}
所有项目都在 /data/web/webapp/webapp/ 中，其中包括 setting.py、urls 等文件。 webapp.py 文件位于 /data/web/webapp/webapp/ 目录下。
import sys, os
import django.core.handlers.wsgi
sys.path.insert(0, '/data/web/webapp/webapp')
os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'
application = django.core.handlers.wsgi.WSGIHandler()
uid和gid为33，它是www-data用户。尝试以以下方式运行uwsgi：
root#uwsgi -s /var/run/uwsgi.sock -x /etc/uwsgi/apps-enabled/webapp.xml
[uWSGI] parsing config file /etc/uwsgi/apps-enabled/webapp.xml
*** Starting uWSGI 0.9.8.3-debian (64bit) on [Wed Dec 14 21:42:02 2011] ***
compiled with version: 4.6.1 on 27 July 2011 18:25:51
writing pidfile to /tmp/uwsgi.pid
uWSGI running as root, you can use --uid/--gid/--chroot options
setgid() to 33
setuid() to 33
your memory page size is 4096 bytes
unlink(): Permission denied [socket.c line 38]
bind(): Address already in use [socket.c line 70]
他们需要什么权限？问题出在哪里.. 如果我以root身份运行uwsgi，错误就会消失，我也看到了
*** WARNING: you are running uWSGI as root !!! (use the --uid flag) ***
your memory page size is 4096 bytes
uwsgi socket 0 bound to UNIX address /var/run/uwsgi.sock fd 3
uwsgi socket 1 bound to UNIX address /tmp/uwsgi.sock fd 4
your server socket listen backlog is limited to 100 connections
*** Operational MODE: single process ***
*** no app loaded. going in full dynamic mode ***
*** uWSGI is running in multiple interpreter mode ***
spawned uWSGI master process (pid: 20732)
spawned uWSGI worker 1 (pid: 20733, cores: 1)
但是当我尝试访问服务器时，nginx返回502错误页面。还有更多的问题：nginx日志中出现权限错误：
2011/12/14 21:57:17 [crit] 20739#0: *1 connect() to unix:///tmp/uwsgi.sock failed (13: Permission denied) while connecting to upstream, client: 10.10.3.111, server: ******, request: "GET /favicon.ico HTTP/1.1", upstream: "uwsgi://unix:///tmp/uwsgi.sock:", host: "****.****.**"
如果在运行时将 /tmp/uwsgi.sock 的所有者更改为 nginx 用户（www-data），则会写入其他日志。
[error] 20739#0: *21 upstream prematurely closed connection while reading response header from upstream,
但仍然出现502错误（
如何解决这个问题？有人可以帮我吗？ 真的想使用nginx+uwsgi而不是apache。 谢谢。
但是，解决方案已经接近了 :) 我现在使用tcp套接字，更改了uwsgi配置并安装了更多的软件包。 最重要的选项是--autoload。 现在uwsgi的配置如下：
<uwsgi>
<module>webapp</module>
<socket>127.0.0.1:5080</socket>
<pythonpath>/data/web/webapp/webapp</pythonpath>
<autoload/>
<daemonize>/var/log/uwsgi_webapp.log</daemonize>
<processes>1</processes>
<uid>33</uid>
<gid>33</gid>
<enable-threads/>
<master/>
<harakiri>120</harakiri>
<max-requests>5000</max-requests>
</uwsgi>
还有其他问题需要解决... uwsgi使用的不是主系统Python版本 >_<
option "pythonpath" found in plugin python26_plugin.so
*** Starting uWSGI 0.9.8.3-debian (64bit) on [Thu Dec 15 22:52:23 2011] ***
compiled with version: 4.6.1 on 27 July 2011 18:25:51
uWSGI running as root, you can use --uid/--gid/--chroot options
setgid() to 33
setuid() to 33
your memory page size is 4096 bytes
*** WARNING: you have enabled harakiri without post buffering. Slow upload could be rejected on post-unbuffered webservers ***
uwsgi socket 0 bound to TCP address 127.0.0.1:5080 fd 4
Python version: 2.6.7 (r267:88850, Aug 3 2011, 12:02:14) [GCC 4.6.1]
Python main interpreter initialized at 0xc47df0
threads support enabled
your server socket listen backlog is limited to 100 connections
*** Operational MODE: single process ***
added /data/web/webapp/webapp/ to pythonpath.
WSGI application 0 (SCRIPT_NAME=) ready on interpreter 0xc47df0 pid: 22983 (default app)
*** uWSGI is running in multiple interpreter mode ***
spawned uWSGI master process (pid: 22983)
spawned uWSGI worker 1 (pid: 22984, cores: 1)
他使用的是Python 2.6.7，但主系统版本是2.7.2，并且所有的Python模块都是为这个版本安装的，所以日志中出现了很多错误 - 反复尝试导入不存在的模块，其中一个典型的错误。
File "/usr/lib/python2.6/dist-packages/django/db/__init__.py", line 78, in <module>
connection = connections[DEFAULT_DB_ALIAS]
File "/usr/lib/python2.6/dist-packages/django/db/utils.py", line 93, in __getitem__
backend = load_backend(db['ENGINE'])
File "/usr/lib/python2.6/dist-packages/django/db/utils.py", line 51, in load_backend
raise ImproperlyConfigured(error_msg)
django.core.exceptions.ImproperlyConfigured: 'django_mongodb_engine' isn't an available database backend.
Try using django.db.backends.XXX, where XXX is one of:
'dummy', 'mysql', 'oracle', 'postgresql', 'postgresql_psycopg2', 'sqlite3'
Error was: No module named django_mongodb_engine.base
那么，如何为uwsgi设置Python的版本？