Troubleshoot DNS

If DNS resolution isn't working properly:

Check CoreDNS status:

kubectl get pods -n kube-system -l k8s-app=kube-dns
kubectl logs -l k8s-app=kube-dns -n kube-system

Verify CoreDNS configuration:

kubectl get configmap -n kube-system coredns -o yaml

Test DNS resolution from inside the cluster:

kubectl run -i --tty --rm debug --image=busybox --restart=Never -- nslookup kubernetes.default