Referrer Spam Blocker

Most referral blockers for NGINX absolutely suck by using a map with thousands of regular expressions. This comes with a huge performance penalty due to regular expressions being evaluated sequentially.

This blocker uses the proper spam bocking technique (tm), which won't ruin your performance!

Installation

Drop the file to an included directory, e.g. /etc/nginx/conf.d:

curl -o /etc/nginx/conf.d/referral-spam.conf https://raw.githubusercontent.com/dvershinin/referrer-spam-blocker/main/referral-spam.conf

Ensure increased hash bucket size, for NGINX to be able to work with larger maps. Create /etc/nginx/conf.d/custom.conf and specify:

map_hash_bucket_size 128;

Add the following to each /etc/nginx/site-available/example.com.conf that needs protection. Inside server { } block:

if ($bad_referer) {
    return 444;
}

Check NGINX configuration for error by running nginx -t. If all good, reload NGINX:

systemctl reload nginx

That's it. No more annoying spammers.

TODO

Consider Moto list as more reputable https://github.com/matomo-org/referrer-spam-list