How do I set up bind via webmin to delegate dns lookups for certain subdomains?

Question

I have several docker containers with some web applications running via docker compose. One of the containers is a custom DNS server with Bind and Webmin installed. Webmin gives a nice web UI allowing me to update Bind DNS configuration without directly modifying the files or SSHing into the container. I have docker setup to lookup DNS in this order:

1. my docker dns server
2. my companies internal dns server
3. google dns server

I have one master zone file for top level domain "example.com" defined in dns server 1. I added an address for server1.example.com and dns resolves correctly. I want other subdomains to be resolved from my companies internal dns server.

• server1.example.com - resolves correctly
• server2.example.com - this host is not referenced in the zone file for docker dns server. I would like to somehow delegate this to my companies dns server (server 2)

The goal is I should be able to do software development for web applications and deploy them on my docker containers. The code makes internal calls to other "example.com" hosts. I want some of those calls to get directed back to other docker containers rather than the real server because I am developing code on both and want to test it end to end.

I don't want to (and can't) modify my companies dns configuration. I am not an expert in bind or dns setup and looking for the simplest solution.

What configuration can achieve this?

Answer 1

I guess the workaround is to use fully qualified name when creating the zone file. Instead of creating a master zone example.com and listing server1 inside that zone I am creating a master zone with server1.example.com. It means I have to create a zone file for every server but I guess its ok to manage with a smaller number of hosts. server2.example.com then doesnt fall inside of a zone and gets resolved using the next dns server in the chain.