Manipulating request headers in VCL

Lets say we want to remove the cookie for all objects in the /images directory of our web server:

sub vcl_recv {
  if (req.url ~ "^/images") {
    unset req.http.cookie;
  }
}

Now, when the request is handled to the backend server there will be no cookie header. The interesting line is the one with the if-statement. It matches the URL, taken from the request object, and matches it against the regular expression. Note the match operator. If it matches the Cookie: header of the request is unset (deleted).