For anyone wanting to set up WireGuard with the Pi-hole DNS blocker: I would advise https://github.com/racbart/wireguard-pihole. Just a simple shell script. No Docker or Kubernetes required. I installed it on the cheapest DigitalOcean VPS, and it has been running without issues for over a month now. (About 6 phones of me and my friends, and a few desktops are using it.)