For instance how can I use my *.domain.com SSL certs and NPM to route containers to a subdomain without exposing them? The main domain is exposed.
You need a DNS service that works with Let’s encrypt
I don’t get it. Npm is a package manager. It doesn’t handle certificates.
You need a DNS service like route 53 (AWS) or similar where let’s encrypt connects via an API and creates the DNS token.
OP isn’t referring to the package manager. They’re talking about Nginx Proxy Manager
Split DNS on your LAN?
Only records permitted to be access on your LAN are responded by a local DNS server. While public DNS still available for your public facing services.
Your wildcard cert will work for both situations as the browser only cares the sni matches the Url in your address bar.
I’m using this right now but I’m switching to having all my services under one domain and blocking non internal ips. Technically someone can access your site by providing the host manually, althought it’s unlikely since they would need to know it
You can use the DNS verification method. Either using nsupdate with bind or what ever protocol your DNS provider and favorite ACME (certbot, acme, lego, etc) utility supports. As long as your DNS server is publically reachable that will work, even if the subdomain itself doesn’t exist publically.
This is what I do as well. I have a public DNS record for my internal reverse proxy IP (no need to expose my public IP and associate it with my domain). I let NPM reach out to the DNS provider to complete verification challenge using an account token, NPM can then get a valid cert from Let’s Encrypt and nothing is exposed. All inbound traffic on 80/443 remains blocked as normal.
I don’t really understand what you’re getting at. The answer to OPs question is to use letsencrypt like everyone else.
They literally didn’t mention LE at all.
SSL is not LetsEncrypt, if you didn’t know.
OP is asking for cases where you don’t want to allow the service (or reverse proxy) to be accessible via the web.
I have that setup, my domain is hosted by OVh and they have an API that you can use to get a wildcard certificate with.
At home I run pihole and that has some sites in as local IPs, but if you look the same site up from OVH you would get an internet IP
