Advice on combined internal DNS resolution across two sites?

rprichard

I have two pfSense boxes at two separate sites, linked together with a site-to-site Wireguard tunnel. I have multiple services at each site that I access through HAProxy via subdomains of a domain I own.

Some of these services are at Site A, and some are at Site B. I would like to be able to access any service from either site using its domain name, as shown below:

service1.mydomain.tld -> service1 @ Site A
service2.mydomain.tld -> service2 @ Site A
service1.siteb.mydomain.tld -> service1 @ Site B
Etc.

The issue is that these services are all internal, and mydomain.tld resolves to a public IP address.

At Site A, I currently have things working with a redirect in the DNS resolver settings from *.mydomain.tld to my HAProxy frontend.

server:
  local-zone: "mydomain.tld" redirect
  local-data: "mydomain.tld 86400 IN A 172.20.0.99"

I am thinking I could have HAProxy redirect to Site B if 'siteb' is in the host name. At Site B, I could have a similar setup, where it redirects to Site A unless 'siteb' is in the host name. I would just need to add a similar DNS redirect at Site B.

This seems a little convoluted, but I can't think of a better way of doing things. Does anyone have any suggestions/advice?

I suppose I could send all requests to one site's HAProxy, then to each site as appropriate, but the ping is significant and I'd like everything to work even if WAN is down.

SteveITS

@rprichard Perhaps I’m misunderstanding but I would use domain overrides to have unbound forward requests to the desired DNS server(s).

keyser

@steveits Completely agree. And If you do not care to maintain overrides on both boxes, you could just do a domain.tld override on one box so any request for that intire domain is served by the box in the other end.

rprichard

@SteveITS that's perfect, thank you! No misunderstanding - I'm just new to networking so I sometimes miss the obvious.