This implementation describes how to configure the BIG-IP® content adaptation feature for adapting HTTP requests. With this feature, a BIG-IP virtual server can conditionally forward HTTP requests to a pool of Internet Content Adaptation Protocol (ICAP) servers for modification, before sending the request to a web server.
In this implementation, you create a standard HTTP virtual server and pool of web servers for processing client requests. The HTTP virtual server accepts each client request in the normal way, but before load balancing the request to the pool of web servers, the virtual server forwards the HTTP request to a special internal virtual server.
The internal virtual server receives the HTTP request from the standard virtual server, and load balances the request to a pool of ICAP servers for modification. After the ICAP server modifies the request, the BIG-IP system sends the request to the appropriate web server for processing.
Content adaptation configuration for modifying HTTP requests
The internal virtual server references the pool of content adaptation servers, including the load balancing method to use for those servers. The internal virtual server also references an ICAP profile, which includes specific instructions for how the BIG-IP system should wrap the HTTP request in an ICAP message for adaptation.
Optionally, the internal virtual server can reference:
Complete the tasks in this implementation to create a BIG-IP® configuration that performs content adaptation for HTTP requests.
You create this ICAP profile when you want to use an ICAP server to wrap an HTTP request in an ICAP message before the BIG-IP® system sends the request to a pool of web servers. The profile specifies the HTTP request-header values that the ICAP server uses for the ICAP message.
A virtual server of type internal provides a destination that a standard type of virtual server can use when forwarding HTTP requests slated for ICAP-based content adaptation.
You perform this task to create a standard virtual server that can forward an HTTP request to an internal virtual server. The internal virtual server then sends the request to a pool of ICAP servers before the BIG-IP® system sends the request to the web server.
After you complete the tasks in this implementation, the BIG-IP® system can perform content adaptation on HTTP requests as they pass through the BIG-IP system during normal HTTP processing. The new objects that this implementation creates are: