[Bug] 0.23.0-beta1 breaks DNS custom nameservers

[MitchTalmadge]

Is this a support request?

• This is not a support request

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

After upgrading from 0.23.0-alpha12 to 0.23.0-beta1, with no other changes at all, queries made to 100.100.100.100 which should use a listed nameserver give status: NXDOMAIN.

Expected Behavior

Queries should return results from the nameservers

Steps To Reproduce

I use the following DNS config:

dns_config:
  override_local_dns: true
  nameservers:
    - 100.64.0.6
  restricted_nameservers:
    foo.bar: # Redacted
      - 100.64.0.2
    baz.foo: # Redacted
      - 100.64.0.2
  domains: []
  magic_dns: true
  base_domain: lorem.ipsum # Redacted

On alpha9, 10, 11, and 12, it works fine. On beta1, it fails.

Environment

- OS: Unraid 6.12.10, running Docker 24.0.9
- Headscale version: 0.23.0-beta1
- Tailscale version: 1.70.0 on MacOS Sonoma

Runtime environment

• Headscale is behind a (reverse) proxy
• Headscale runs in a container

Anything else?

No response

[badsmoke]

hey a workaround is to add these domains in addition to the injecded config.

  # Search domains to inject.
  domains: [foo.bar, baz.fooz]
  
```

[kradalby]

I've started on #2034, with some background on this mess up, would be keen to hear thoughts.

[kradalby]

I think #2034 addresses this, would it be possible for you to help me test it? would be great to avoid another bad release like beta1.

Binary is available here: https://github.com/juanfont/headscale/actions/runs/10195837541?pr=2034

[MitchTalmadge]

Hey thank you for making a fix for this. I haven't had time to try it yet. I hope to find time soon. Thanks again