How do I configure a conditional forwarder with CoreDNS in my Amazon EKS cluster?
I want to configure a conditional forwarder with CoreDNS in my Amazon Elastic Kubernetes Service (Amazon EKS) cluster.
"I want to configure a conditional forwarder with CoreDNS in my Amazon Elastic Kubernetes Service (Amazon EKS) cluster.Short descriptionYou can use CoreDNS to configure conditional forwarding for DNS queries sent to the domains resolved by a customized DNS server. For more information, see Customizing DNS Service on the Kubernetes website.Important: Apply the modifications in the following resolution to self-managed CoreDNS only. To make configuration changes to the CoreDNS Amazon EKS add-on, determine the settings that Amazon EKS manages by checking the Amazon EKS add-on configuration. Check the add-on configuration before making any changes, because modifying a field managed by Amazon EKS prevents Amazon EKS from managing the add-on. This could result in your changes being overwritten when an add-on is updated.Resolution1.    Modify the CoreDNS ConfigMap and add the conditional forwarder configuration:$ kubectl -n kube-system edit configmap corednsOutput:apiVersion: v1kind: ConfigMapmetadata:  annotations:  labels:    eks.amazonaws.com/component: coredns    k8s-app: kube-dns  name: coredns  namespace: kube-systemdata:  Corefile: |    .:53 {        errors        health        kubernetes cluster.local in-addr.arpa ip6.arpa {          pods insecure          fallthrough in-addr.arpa ip6.arpa        }        prometheus :9153        forward . /etc/resolv.conf        cache 30        loop        reload        loadbalance    }    domain-name:53 {        errors        cache 30        forward . custom-dns-server        reload    }Note: Replace domain-name with your domain name. Replace custom-dns-server with your custom DNS server IP address.2.    Verify that domain name resolution works:$ kubectl run busybox --restart=Never --image=busybox:1.28 -- sleep 3600$ kubectl exec busybox -- nslookup domain-nameNote: Replace domain-name with your domain name.Follow"