Re: Conditionally Setting HTTP Response Header (Apache Users)

You can use ExpiresDefault/ExpiresByType (this adds both an Expires and Cache-Control: max-age header to simultaneously support HTTP 1.0 and HTTP 1.1) or use LocationMatch. For example, I could distinguish between static content requests (requests to *.gif) vs dynamic content requests (requests to *.jsp or *.do for a Struts application) using the LocationMatch. I couldn't find a way of using LocationMatch to work with the content-type of the response, which was what I needed for file download requests. Nor could I find a way of checking whether the header was set, before setting it. (I'm still asking the question).

On Mon, Mar 15, 2010 at 12:50 PM, Anurag Kapur <anuragkapur@xxxxxxxxx> wrote:

Hello,

I am looking for some help to set HTTP response headers conditionally. I have a setup where HTTPD sits in front of Tomcat and proxies requests to it.

Problem Statement

Set a Cache-Control max-age directive in the HTTP response header through HTTPD if it doesn't already exist. In addition if HTTPD after detecting that the directive is not already set in the response header, it should set one depending on the response mime-type.

Example:

HTTPD proxies a request to tomcat -> Tomcat processes the request and send back the response to HTTPD -> HTTPD checks if Cache-Control max-age directive is set in the response header. If present it does no changes to the response header and simply forwards the response back to the user. However, if the Cache-Control max-age directive is not present it sets one depending on the response mime type (say max-age=900 for text/html and max-age=1800 for image/gif)

System Info

$ apachectl -version

Server version: Apache/2.2.9 (Unix)

Server built: Sep 12 2008 16:23:39

$ uname -a

SunOS vm-sol10-45 5.10 Generic_127128-11 i86pc i386 i86p

What I Have Tried

I have been trying to work with mod_setenvif module to start but have not made any progress and thus seeking your help.

Any inputs would be highly appreciated.

Regards

Anurag

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Anurag Kapur
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Sapient Corporation.

http://www.linkedin.com/in/anuragkapur

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