I got into the self-hosting scene this year when I wanted to start up my own website run on old recycled thinkpad. A lot of time was spent learning about ufw, reverse proxies, header security hardening, fail2ban.
Despite all that I still had a problem with bots knocking on my ports spamming my logs. I tried some hackery getting fail2ban to read caddy logs but that didnt work for me. I nearly considered giving up and going with cloudflare like half the internet does. But my stubbornness for open source self hosting and the recent cloudflare outages this year have encouraged trying alternatives.
Coinciding with that has been an increase in exposure to seeing this thing in the places I frequent like codeberg. This is Anubis, a proxy type firewall that forces the browser client to do a proof-of-work security check and some other nice clever things to stop bots from knocking. I got interested and started thinking about beefing up security.
I'm here to tell you to try it if you have a public facing site and want to break away from cloudflare It was VERY easy to install and configure with caddyfile on a debian distro with systemctl. In an hour its filtered multiple bots and so far it seems the knocks have slowed down.
My botspam woes have seemingly been seriously mitigated if not completely eradicated. I'm very happy with tonights little security upgrade project that took no more than an hour of my time to install and read through documentation. Current chain is caddy reverse proxy -> points to Anubis -> points to services
Good place to start for install is here
Something that hasn't been mentioned much in discussions about Anubis is that it has a graded tier system of how sketchy a client is and changing the kind of challenge based on a a weighted priority system.
The default bot policies it comes with has it so squeaky clean regular clients are passed through, then only slightly weighted clients/IPs get the metarefresh, then its when you get to moderate-suspicion level that JavaScript Proof of Work kicks. The bot policy and weight triggers for these levels, challenge action, and duration of clients validity are all configurable.
It seems to me that the sites who heavy hand the proof of work for every client with validity that only last every 5 minutes are the ones who are giving Anubis a bad wrap. The default bot policy settings Anubis comes with dont trigger PoW on the regular Firefox android clients ive tried including hardened ironfox. meanwhile other sites show the finger wag every connection no matter what.
Its understandable why some choose strict policies but they give the impression this is the only way it should be done which Is overkill. I'm glad theres config options to mitigate impact normal user experience.