haven

kubectl create secret generic adguardhome-password \ 
    --from-literal=password='your_adguardhome_password' \ 
    --from-literal=username='your_adguardhome_username' -n dns

Add AdGuardHome to CoreDNS configmap fallback:

Edit the CoreDNS configmap:

kubectl edit configmap coredns -n kube-system

Replace the forward line with the following:

    forward . <ADGUARDHOME_IP> <ADGUARDHOME_IP_2>

This will use AdGuardHome as the primary DNS server and a secondary one as a fallback, instead of using the default Kubernetes CoreDNS server.

You may also use /etc/resolv.conf to forward to the node's own DNS resolver, but it depends on whether it's well configured or not. Since it's Linux, we never know.

Ideally, since DNS is required for fetching the container image, you would have AdGuardHome as first and then a public DNS server as second (fallback).