The problem with these kind of things is that now I need to ask around some IPs to connect to, as I see there's no automatic peer discovery.
Sounds awesome nonetheless.
What would automatic discovery even do? Add you to some worldwide IP overlay on top of internet? What would be the use of that?
I did had a use case in the past for peer to peer VPNs, mainly because in the 2000s, most hosting companies would only provide you crappy VMs with a single public interface. If you needed some control over the network, subnets, etc, then you would need some kind of overlay. This, added with the fact that you would typically have dozens of heterogeneous boxes at different providers, made maintaining a traditional host to host ipsec full mesh nightmarish. I used n2n (a peer to peer VPN) to reconciliate these various internet facing boxes in a single private IP network.
Nowadays, cloud providers are much more evolved, and offer you full configuration of multiple public/private interfaces, so recreating subnets over public facing boxes is not really a concern, which is why IMHO peer to peer VPNs do not serve much purpose in 2021.
It's seems really simple to use as well: The linked implementation in PHP on https://vpncloud.ddswd.de/docs/beacons/php-service/ is only around 80 lines of code and extremely simple and due to the beacon design doesn't compromise the security of your setup if anything goes wrong.
I did had a use case in the past for peer to peer VPNs, mainly because in the 2000s, most hosting companies would only provide you crappy VMs with a single public interface. If you needed some control over the network, subnets, etc, then you would need some kind of overlay. This, added with the fact that you would typically have dozens of heterogeneous boxes at different providers, made maintaining a traditional host to host ipsec full mesh nightmarish. I used n2n (a peer to peer VPN) to reconciliate these various internet facing boxes in a single private IP network.
Nowadays, cloud providers are much more evolved, and offer you full configuration of multiple public/private interfaces, so recreating subnets over public facing boxes is not really a concern, which is why IMHO peer to peer VPNs do not serve much purpose in 2021.