Configuring Varnish to rewrite Expires/Cache-Control headers for client-side caching
Solution 1:
This does the trick:
sub vcl_fetch {
..
if (req.url ~ "\.css$") {
set obj.http.magicmarker = "1";
}
..
}
sub vcl_deliver {
..
if (resp.http.magicmarker) {
unset resp.http.magicmarker;
set resp.http.Cache-Control = "...";
set resp.http.Expires = "...";
set resp.http.Age = "...";
}
..
}