How to map sub domain to internal IP adress

Question

I'd like to reach some internal services like the web client of my NAS (Synology DSM) through dedicated sub domains like https://nas.example.com.

The services are fully running and accessible via internal IPs like https://192.168.0.200:5001.

I obviously own the domain example.com and have an Apache server up & running.

There are basically 2 reason why I'd like to achieve the above:

• The sub domain nas.example.com is easier to remember than 192.168.0.200:5001
• I'd like to use my existing HTTPS certificates for nas.example.com which I can't with internal IP addresses

I've already played around with Apache's mod_rewrite but had no success at all. Unfortunately I can't tell if this scenario is even possible with mod_rewrite or if I just didn't configure it correct.

Some notes:

• The services should not be accessible from outside but only from within my LAN.
• Ideally, they should also be accessible via the sub domains when connected with the network from outside via SSH tunnels. Therefore a dedicated DNS server like dnsmasq is not what I'm looking for since that would only treat requests from within the LAN (I guess...).

Answer 1

It's easier to do with nginx, but apache can handle this too, using mod_proxy

You should set up a VirtualServer for domain nas.mysite.com and enable Reverse Proxy for this virtual server:

ProxyPass "/"  "http://192.168.0.200:5001"
ProxyPassReverse "/"  "http://192.168.0.200:5001"

Answer 2

Don't bother setting up a reverse proxy when:

The services should not be accessible from outside but only from within my LAN.

Simply create a DNS record that points nas.example.com to your IP-address

nas.example.com. IN A 192.168.0.200

Non-internet routable ip-addresses from the 192.168.0.0/16 subnet will only work within your own LAN.

Then configure the DSM web interface to run on port 80, the default port for HTTP and you won't need to use a port number like 5000 in the URL anymore.