Redirecting HTTP requests using the IP address of a client in your Apache configuration

Given you have two different customers which need to access the same resource. The URL should be the same for both, e.g. “https://www.example.org/resource.db”, but the response should be different.

From “2.4” on the apache httpd can make use of its expressions in its rewrite engine. There’s an expression -R which does the “same as %{REMOTE_ADDR} -ipmatch ..., but more efficient” which matches the IP address of a requesting client to an IP network.

To redirect requests internally use the following in your apache configuration. Besides expressions, this configuration uses one of httpd’s “Rewrite Rule Flags”: END. This flag prevents any subsequent rewrite processing if the rule matches.

<VirtualHost 10.0.0.1:80>
  ServerName www.example.org
  ServerAlias www

  UseCanonicalName Off

  ServerAdmin admin@example.org

  DocumentRoot /srv/www/

  <Directory "/srv/www/">
    AllowOverride None
    Require all granted
  </Directory>

  RewriteCond    expr "-R '10.0.1.0/24'"
  RewriteRule    ^/resource.db$  /customer1/resource.db [END]

  RewriteCond    expr "-R '10.0.2.0/24'"
  RewriteRule    ^/resource.db$  /customer2/resource.db [END]

  RewriteRule    ^/resource.db$  /resource.db [END]
</VirtualHost>

The most interesting part is this. In this code snippet, the webserver checks for the client IP address and redirects the request internally if the client IP is in the given IP range and stops checking for other rewrite rules. The last line is a default redirect rule which always matches.

RewriteCond    expr "-R '10.0.1.0/24'"
RewriteRule    ^/resource.db$  /customer1/resource.db [END]

RewriteCond    expr "-R '10.0.2.0/24'"
RewriteRule    ^/resource.db$  /customer2/resource.db [END]

RewriteRule    ^/resource.db$  /resource.db [END]

Try it yourself! Happy Redirecting! Thanks for reading!