停止Apache阻止ETag

Question

I have written a web application that uses someone else's API that requires ETags. I have tried this code:

header("ETagbleh: whatever");

Which works perfectly. However, when I set this:

header("ETag: whatever");

Nothing happens. I have heard that it may be Apache blocking the sending of ETags, but I'm not sure. I've done a search for ETag in my apache2.conf and can't find anything to uncomment / remove, so I came here to ask.

So, how can I stop Apache blocking my headers?

Edit: I'm using Apache 2.2.22, and I assumed that the scripting language was irrelevant, given that PHP 5.4.4, which is what I'm using, can set any other header fine.

Answer 1

I've had the same problem.

A very popular way to remove ETags in Apache2 is adding the following configuration:

Header unset ETag
FileETag None

Remove the first config line, if you find it in your configuration.

A bit more difficult to find is mod_include causing the problem. By default the ETag-Header is removed by this module. But you can allow it by configuration. So add something like this:

 <IfModule mod_include.c>
     SSIETag on
 </IfModule>

See here for more information.