How to get local SSL and use your public domain for local internal subdomains?
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.
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
Would you elaborate on this concern? I'm not sure I understand but I'd like to.
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.
This is the way.
Vastly superior to local dns.
You need a DNS service that works with Let's encrypt
NPM is in my post…
Then you're all set, issue certs over DNS-01 challenge in NPM, and create records in your local DNS server that point to the NPM IP for each domain you want to use.
OP is asking for cases where you don't want to allow the service (or reverse proxy) to be accessible via the web.
As I understand it, OP just wants to hide (=remove) the subdomains from the public URLs.
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
How we've done it recently:
No need to have port 80 open to the world, no need for a reverse proxy, no need for NAT rules to point it to the right machine, no need to even have DNS set up for the hostname. All of that BS is removed.
The token proves your authentication and LetsEncrypt will generate the certs.
I do exactly this with traefik.
I followed this guide: https://youtu.be/liV3c9m_OX8
I recommend this one instead: https://youtu.be/n1vOfdz5Nm8
Same guy, just fresh version of Traefik 😁
If you have wildcard certs, you just install them everywhere your services are running.
As far as redirects go, you just 302 redirect from one host to another.
Unless you're asking about resolving hosts on your internal network and public ones differently, which is a lot more complicated than you probably want to deal with if you're already kind of lost. Just setup a VPN to your internal network and be done with it. Otherwise setup a local DNS resolver to bridge your public DNS and local requests.