This configuration makes Apache act as an HTTP proxy:

   1  <VirtualHost *:8080>
   2  ProxyRequests On
   3  ProxyVia On
   4  #ProxyRemote * http://...:8080 Uncomment to route requests through another proxy
   5  <Proxy *>
   6  	Order deny,allow
   7  	Deny from all
   8  	Allow from all # Not a good idea, set to allowed IP ranges
   9  </Proxy> 
  10  	
  11  CacheRoot "/tmp"
  12  CacheMaxExpire 24
  13  CacheLastModifiedFactor 0.1
  14  CacheDefaultExpire 1
  15  
  16  ServerName my-proxy
  17  
  18  ErrorLog "/var/log/apache2/proxy-error.log"
  19  CustomLog "/var/log/apache2/proxy-access.log" common
  20  </VirtualHost>

Also read this.

Tips

You can use mod_rewrite to rewrite requests. To rewrite root (/) to /temporary_outage you could use the following rewrite:

   1  RewriteCond %{HTTP_HOST} ^(www\.)?xxx\.com 
   2  RewriteRule /$ http://%{HTTP_HOST}/temporary_outage/ [P,L]

   1  function link_back($blacklist = array())
   2  	{
   3  		$parameters = split("&", $_SERVER['QUERY_STRING']);
   4  		
   5  		$uri = array_shift(split("\?", $_SERVER['REQUEST_URI']));
   6  
   7  		$index = 0;
   8  		
   9  		foreach($parameters as $parameter)
  10  		{
  11  			$parameter = split("=", $parameter);
  12  			
  13  			$name = $parameter[0];
  14  			$value = $parameter[1];
  15  			
  16  			if(in_array($name, $blacklist))
  17  			{
  18  				unset($parameters[$index]);
  19  			}
  20  			
  21  			$index++;
  22  		}
  23  		
  24  		if(count($parameters) > 0)
  25  		{
  26  			$parameters = "?".join("&", $parameters);	
  27  		}
  28  		else
  29  		{
  30  			$parameters = '';
  31  		}
  32  		
  33  		return $uri.$parameters;
  34  	}

Usage:

   1  # URI is /wow_amazing_code?not_wanted=23&wanted=1
   2  
   3  echo link_back(array('not_wanted')); # prints out /wow_amazing_code?wanted=1

Install mod_security, for some stupid reason it’s not included in Debian Etch, and for some even more stupid reason you’re not allowed to change the value of the Server header.

Anyway, to change the server signature, and enable voodoo magic:

   1  <IfModule mod_security2.c>
   2      # Basic configuration options
   3      SecRuleEngine On
   4      SecRequestBodyAccess On
   5      SecResponseBodyAccess Off
   6  
   7      # Handling of file uploads
   8      # TODO Choose a folder private to Apache.
   9      # SecUploadDir /opt/apache-frontend/tmp/
  10      SecUploadKeepFiles Off
  11  
  12      # Debug log
  13      SecDebugLog /var/log/apache2/modsec_debug.log
  14      SecDebugLogLevel 0
  15  
  16      # Serial audit log
  17      SecAuditEngine RelevantOnly
  18      SecAuditLogRelevantStatus ^5
  19      SecAuditLogParts ABIFHZ
  20      SecAuditLogType Serial
  21      SecAuditLog /var/log/apache2/modsec_audit.log
  22  
  23      # Maximum request body size we will
  24      # accept for buffering
  25      SecRequestBodyLimit 131072
  26  
  27      # Store up to 128 KB in memory
  28      SecRequestBodyInMemoryLimit 131072
  29  
  30      # Buffer response bodies of up to
  31      # 512 KB in length
  32      SecResponseBodyLimit 524288
  33  
  34      SecServerSignature "Dummy value"
  35  </IfModule>
  36  

I use this configuration on my development machine when I need mod_rewrite; it’s not meant for production:

   1  <VirtualHost *:80>
   2  ServerName dev.xxx.com
   3  
   4  # Enable URL rewriting
   5  RewriteEngine On
   6  
   7  # Rewrite index to check for static pages
   8  RewriteRule ^/$ /index.html [QSA]
   9  
  10  # Rewrite to check for Rails cached page
  11  RewriteRule ^([^.]+)$ $1.html [QSA]
  12  
  13  # Redirect all non-static requests to cluster
  14  RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f
  15  RewriteRule ^/(.*)$ balancer://mongrel_cluster%{REQUEST_URI} [P,QSA,L]
  16  
  17  DocumentRoot  "/Users/christian/Documents/Projects/xxx/public"
  18  <Directory "/Users/christian/Documents/Projects/xxx/public">
  19       Options Indexes FollowSymLinks
  20  
  21       AllowOverride None
  22       Order allow,deny
  23       Allow from all
  24   </Directory>
  25  
  26  </VirtualHost>
  27  
  28  <Proxy balancer://mongrel_cluster>
  29    BalancerMember http://127.0.0.1:3000
  30  </Proxy>