DNS resolution of Container Domain Names

[BickfordA]

I have a Docker Compose setup arranged in a tree structure where the root container runs a Caddy web server. This server has separate virtual networks configured for three containers that provide different services to it. I would like to use the OrbStack container domain names, but when I resolve the web server container domain name from one of the sub-containers, it returns the IP addresses for all the networks to which the root Caddy container is connected. Unfortunately, the sub-container can only connect to one of those IP addresses, as the others are on different subnets. This often results in connection failures due to the wrong IP address being used.

Is there a way to configure the DNS so that it only returns the IP address for the same subnet that the request originated from?

[jmotes]

I wonder if adding the orbstack domains to your caddy aliases would help. I haven't tried it, but I'm adding custom domains that way in my docker compose setup to match the entries in my Caddyfile:

caddy:
  image: caddy:2-alpine
  networks:
    default:
      aliases:
        - frontend.project-name.local
        - admin.project-name.local

This enables container-to-container communication via domain for me. The only caveat is you will still need to install the root SSL cert on every container, assuming you're using internal TLS.

FYI I have a similar question too. I'm curious if a resolution for it would work for both of our needs:

https://github.com/orgs/orbstack/discussions/1285