I have a Django app running under Apache2 and mod_wsgi and, unfortunately, lots of requests trying to use the server as a proxy. The server is responding OK with 404 errors but the errors are generated by the Django (WSGI) app, which causes a high CPU usage.
If I turn off the app and let Apache handle the response directly (send a 404), the CPU usage drops to almost 0 (mod_proxy is not enabled).
Is there a way to configure Apache to respond directly to this kind of requests with an error before the request hits the WSGI app?
I have seen that maybe mod_security would be an option, but I'd like to know if I can do it without it.
EDIT. I'll explain it a bit more.
In the logs I have lots of connections trying to use the server as a web proxy (e.g. connections like GET http://zzz.zzz/ HTTP/1.1 where zzz.zzz is an external domain, not mine). This requests are passed on to mod_wsgi which then return a 404 (as per my Django app). If I disable the app, as mod_proxy is disabled, Apache returns the error directly. What I'd finally like to do is prevent Apache from passing the request to the WSGI for invalid domains, that is, if the request is a proxy request, directly return the error and not execute the WSGI app.
EDIT2. Here is the apache2 config, using VirtualHosts files in sites-enabled (i have removed email addresses and changed IPs to xxx, change the server alias to sample.sample.xxx). What I'd like is for Apache to reject any request that doesn't go to sample.sample.xxx with and error, that is, accept only relative requests to the server or fully qualified only to the actual ServerAlias.
default:
<VirtualHost *:80>
ServerAdmin
alejandro[email protected]
ServerName X.X.X.X
ServerAlias X.X.X.X
DocumentRoot /var/www/default
<Directory />
Options FollowSymLinks
AllowOverride None
</Directory>
<Directory /var/www/>
Options FollowSymLinks
AllowOverride None
Order allow,deny
allow from all
</Directory>
ErrorDocument 404 "404"
ErrorDocument 403 "403"
ErrorDocument 500 "500"
ErrorLog ${APACHE_LOG_DIR}/error.log
LogLevel warn
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
actual host:
<VirtualHost *:80>
ErrorDocument 404 "404"
ErrorDocument 403 "403"
ErrorDocument 500 "500"
WSGIScriptAlias / /var/www/sample.sample.xxx/django.wsgi
ServerAdmin
alejandro[email protected]
ServerAlias sample.sample.xxx
ServerName sample.sample.xxx
CustomLog /var/www/sample.sample.xxx/log/sample.sample.xxx-access.log combined
Alias /robots.txt /var/www/sample.sample.xxx/static/robots.txt
Alias /favicon.ico /var/www/sample.sample.xxx/static/favicon.ico
AliasMatch ^/([^/]*\.css) /var/www/sample.sample.xxx/static/$1
Alias /static/ /var/www/sample.sample.xxx/static/
Alias /media/ /var/www/sample.sample.xxx/media/
<Directory /var/www/sample.sample.xxx/static/>
Order deny,allow
Allow from all
</Directory>
<Directory /var/www/sample.sample.xxx/media/>
Order deny,allow
Allow from all
</Directory>
</VirtualHost>
