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apachemod-expires

Overwrite cache-headers with mod_expires

I want to set cache-headers using the mod_expires module from apache. My configuration looks somewhat like this:

<LocationMatch ^/static >
    ExpiresDefault "access plus 1 years"
</LocationMatch>

The problem is, that the files are generated by a third system I don't control. These system provides files with the following headers:

Date Mon, 24 Oct 2011 08:39:02 GMT
Cache-Control no-cache,no-store,must-revalidate
Pragma no-cache
Expires Thu, 01 Dec 1994 16:00:00 GMT

These headers makes it impossible to set the cache-headers with mod_expires. http://httpd.apache.org/docs/2.2/mod/mod_expires.html tells us why:

When the Expires header is already part of the response generated by the server, for example when generated by a CGI script or proxied from an origin server, this module does not change or add an Expires or Cache-Control header.

Is there any possible way to circumvent this rule and overwrite the headers with mod_expires?

Update: One possible solution, to avoid this limitation is to use only mod_headers to set the cache-headers. Unfortunately, this isn't an alternative because the values have to be calculated.

Thanks it advance.

Solution

  • Unfortunately, it's a known limitation and we had to fall back to use only mod_headers.