Forum Discussion

Michael_Yates's avatar
Michael_Yates
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Nov 14, 2006

URI Rewrite for Server Pool

I have an issue which after reviewing numerous other posts...isn't covered.

 

 

I have a site connected to a server pool that is accessed by a normal URL (http://website.domain.com), but returns the server name, access port, and directory (http://servername:5555/directory).

 

 

The problem is that I need the Server Name Portion stripped on the return to the Browser, but the IRule needs to be able to do this for a Server Pool of 2 or more servers.

 

 

In addition anything past the URI / must remain unchanged. I've tried several solutions the following being the last to no avail.

 

 

 

when HTTP_RESPONSE_CONTINUE {

 

set newhost "http://website.domain.com"

 

if { [HTTP::header host] contains "servername:5555/" } {

 

HTTP::header replace host $newhost

 

}

 

}

 

 

Can someone help me or point me in the right direction?
application delivery
devops
irule editor
iRules
  • Joe_Pruitt's avatar
    Joe_Pruitt
    Nov 15, 2006
    A few corrections. In the HTTP protocol, the server does not return a server name and location as part of the HTTP response.

    Here's a trace for a request for http://www.foo.com/index.html

    GET /index.html HTTP/1.0

    User-Agent: browser-id-string

    Host: www.foo.com

    Pragma: no-cache

    Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*

    and here's the response:

    HTTP/1.1 200 OK

    Date: Wed, 15 Nov 2006 19:00:12 GMT

    Server: server-id-string

    Last-Modified: Fri, 18 Mar 2005 15:33:33 GMT

    ETag: "75e5-ced-19dd0d40"

    Accept-Ranges: bytes

    Content-Length: 3309

    Connection: close

    Content-Type: text/html; charset=ISO-8859-1

    Content...

    As you'll see there is no Host header in the response, nor any host or uri indication whatsoever.

    The URI in the browser is based on the URL in the initial request. A server can opt to change this by issuing a HTTP Redirect (ie. a HTTP 301 response) to the browser with the Location Header containing the alternate URL to then connect to.

    With that being said, I can only assume that you would like the BIG-IP and iRules to do the 30x redirection for you. This can be done by changing the Host header in the request like this

    HTTP::header replace "Host" "servername:5555"

    and changing the URI with the HTTP::uri command

    HTTP::uri "/directory[HTTP::uri]"

    You may want to do something different with the uri but you get the point.

    One other thing I noticied is that you took the host to contain the protocol (ie http://). This is not the case. The host is the section right after the protocol and before the first slash.

    So for this uri: http://servername:5555/directory/index.txt, the value of HTTP::host is "servername:5555" and HTTP::uri is "/directory/index.txt".

    BTW, in the future, you might want to post these types of questions to the iRules v9x forum as this forum is for questions regarding the iRules Editor application.

    -Joe