I followed this guide: https://notthebe.ee/blog/easy-ssl-in-homelab-dns01/
But my Nginx Proxy Manager is running on a VPS that is connected to my local network through a WireGuard tunnel. Could that be an issue? I don’t know why it’s not working?
My NPM is also accessible to the local IP of my homeserver on which WireGuard is running.
It’s not clear what’s the purpose of NPM in your case. Do you want to serve internal network or expose to Internet. If it’s the latter, you need to see what interface you exposed NPM port on (have to be your public network - VPS IP), your firewall needs to allow incoming connections on that port. Most likely you will be using port 443 and maybe 80 for redirect (checkbox in NPM always use TLS). Use IP address first to eliminate DNS issues. Once IP is valid test DNS with nslookup/dig to see if it resolves to your IP.
OpenSSL command needs to be executed from VPS to eliminate network issues and just validate certificate setup. The IP and port would depend on what port you exposed. 127.0.0.1 should work from that context. Once you see certificate you can execute openssl command from your local and use WireGuard tunnel IP to connect to service. This is for internal network.
NPM should serve as both, but only issuing SSL certificates for my local network is the issue. Have you taken a look at the tutorial I’ve linked in the original post?
And what do you mean with the port I’ve exposed? Exposed where? NPM uses port 81.
Yeah I looked at tutorial. Port 81 is only for management (NPM admin gui). Then you have your traffic ports for proxy services. Those would be 80 and 443 normally. You would need to expose those ports to the Internet if you want to access NPM/proxy your service. Port 81 shouldn’t be exposed on your public interface make sure it isn’t or at least have firewall rule to allow only local network (ideally management network/vlan)