common varnish vcl functions

varnish-snippets.vcl

# call fucntion in vcl_res
# Throw error on spam bot comment attempt
# if first letter of comment ID is not numeric, throw 404.
sub clean_comment {
  if (req.url ~ "comment\/reply\/\d*\/\D") {
    error 404 "Page Not Found";
  }
}


# normalize url
sub normalize_req_url {
  if (req.url ~ "^/(?:\?.*)?$") {
    set req.url = "/";
  }

  if (req.url ~ "(\?|&)(campname|camplink|utm_[a-z]+)") {
    set req.url = regsuball(req.url, "(campname|camplink|utm_[a-z]+)=[%\._A-z0-9-]+&?", "");
  }
  set req.url = regsub(req.url, "(\?&|\?|&)$", "");
}

## block specific hostname

if ( req.http.host ~ "(hostname\.com)$" ) {
    error 403 "Access denied";
  }