Allow updating subdomains without changing the base domain using dynamic_domains

[iwismer]

Let say I own example.com and want to update some subdomains for it. I'd use the following config:

{
	dynamic_dns {
		provider cloudflare {env.CLOUDFLARE_API_TOKEN}
		domains {
			# This is required to actually update subdomains
			example.com
		}
		dynamic_domains
	}
}

foo.example.com {
	redir http://google.com
}
bar.example.com {
	redir http://google.com
}

Then, looking in my cloudflare dashboard, I'd see the following A records:

• example.com -> 1.1.1.1
• foo.example.com -> 1.1.1.1
• bar.example.com -> 1.1.1.1

But, I don't want to dynamically update the base example.com record, but it doesn't seem like there's a way to set this up.

I'd like there to be a way to update using dynamic_domains a way to update the subdomains (foo.example.com) only, without updating the A/AAAA record for the base domain (example.com).

Hopefully this example makes sense, and I'm not just missing some obvious configuration in the docs.

A specific example of where this is useful is when I have a single domain with content hosted from multiple servers. With the current implementation, they will fight over the base domain A/AAAA record and constantly be switching it back and forth.

[mholt]

In the domains block, the first argument of each line is the zone name, followed by individual subdomains. Since you don't list any subdomains, IIRC it assumes the whole zone.

[iwismer]

So does this mean I need to setup DNS zones in order to prevent the main domain from having its DNS updated?

[mholt]

A DNS zone is an authority boundary -- typically a registered domain name. So if your domain is example.com, you need to do something like example.com foo bar near the top of your Caddyfile to update subdomains.

[iwismer]

What I'm asking for here is to be able to update the records for subdomains without updating the record for the root domain.

[mholt]

Right, that's what example.com foo bar does. example.com @ would update records for the "root" domain.