Rancher 2.4.2 - CoreDNS - upstreamnameservers priority order

Rancher 2.x
1

Hi everyone,
I setup two dns upstream name servers as detailed here below. The pb is that the server 10.114.0.1 is never triggered which ever its position in the list.
For some domain names, I rather need the internal@ip (provided by DNS @10.114.0.1) rather the Internet@ip (provided by DNS @100.126.0.41)
I am able to get the internal@ip only when the list is made of 10.114.0.1 as single entry but in this case no way resolve Internet domaine names.
Thx for your support. Regards.

> kubectl -n kube-system get configmap coredns -o go-template={{.data.Corefile}}
.:53 {
    errors
    health {
      lameduck 5s
    }
    ready
    kubernetes cluster.local in-addr.arpa ip6.arpa {
      pods insecure
      fallthrough in-addr.arpa ip6.arpa
   }
    prometheus :9153
    forward . 10.114.0.1 100.126.0.41 
    cache 30
    loop
    reload
    loadbalance

}

2

This is not how forwarding works. The list is randomized and then the second entry is only used of the first one is down. It is not “try server A and if you don’t like the answer that can’t back try server B”, it’s “try server A and if A is totally unresponsive switch to server B”.

3

Thanks Vincent for your swift reply.
I gonna rather trigger stub domains option as detailed here below.
However, I do not find Rancher documentation inputs about the dns.stubdomains syntax in the cluster.yml file i.e. how to translate here under ConfigMap into cluster.yml dns entry ?
Thx & Regards. Richard

apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: |
    .:53 {
        errors
        health
        kubernetes cluster.local in-addr.arpa ip6.arpa {
           pods insecure
           fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        forward . 100.126.0.41
        cache 30
        loop
        reload
        loadbalance
    }
    tech.orange:53 {
        errors
        cache 30
        forward . 10.114.0.1
    }