Action caching with multiple domains

I have recently setup some action caching in my Rails app and everything
seems to be working fine. I am using file store pointing at /tmp/cache.
The
problem I am running into is that separate cache directories are being
created for different domain names that point at the same server. For
example mysite.com and www.mysite.com will have different cache
directories.
It seems like it should be easy to force these into a single cache
directory. But I have not been able to puzzle this one out. Is there a
config variable that can be set to override the url or is this best
handled
with mod_rewrite? I have played around with mod_rewrite in an effort to
fix
this issue, with no results to this point.

Any help is appreciated.

–Tim R.

Just for the record I did figure out how to resolve this issue. I was
able
to resolve it by adding the following to my apache vhost file before the
normal proxy rewrites.

RewriteCond %{HTTP_HOST} !^fully.qualified.domain.name [NC]
RewriteCond %{HTTP_HOST} !^$
RewriteRule ^/(.*) http://fully.qualified.domain.name/$1
[L,R,NE]

–Tim