Apache redirect and set cache headers?

Doing a redirect in Apache is easy (mod_alias):

RedirectMatch ^.*$ http://portal.example.com/

Setting cache headers is equally easy:

Header set Cache-Control max-age=0
Header set Expires "Thu, 01 Dec 1994 16:00:00 GMT"

(I don't want this cached)

But! It seems you can't combine the two. This configuration results in the redirect being sent, but not the the headers:

<VirtualHost *:80>
        ServerName __default__
        Header set Cache-Control max-age=0
        Header set Expires "Thu, 01 Dec 1994 16:00:00 GMT"
        RedirectMatch ^.*$ http://portal.example.com/
</VirtualHost>

Example of what actually happens:

jb@apto % telnet 192.168.0.1 80
Trying 192.168.0.1...
Connected to redirector.example.com.
Escape character is '^]'.
GET / HTTP/1.1
Host: foo

HTTP/1.1 302 Found
Date: Sat, 21 Aug 2010 09:36:38 GMT
Server: Apache/2.2.9 (Debian) Phusion_Passenger/2.2.9
Location: http://portal.example.com/
Vary: Accept-Encoding
Content-Length: 316
Content-Type: text/html; charset=iso-8859-1

(etc)

Any ideas for how to return a redirect with cache headers?

Try adding the "always" condition to your Header directive, so it should look like this:

Header always set Cache-Control max-age=0
Header always set Expires "Thu, 01 Dec 1994 16:00:00 GMT"

This should work, without the "always" condition I believe it defaults to "onsuccess" which is defined as any 2xx response code.