Hints: dns-resolution

Hint 1

Services can't resolve DNS names. Test from inside a pod: - kubectl exec -n grokdevops <pod> -- nslookup kubernetes.default

Hint 2

The issue is in the cluster DNS layer. Check CoreDNS: - kubectl get pods -n kube-system -l k8s-app=kube-dns - kubectl logs -n kube-system -l k8s-app=kube-dns --tail=10

Hint 3

Check resolv.conf and CoreDNS configuration: - kubectl exec -n grokdevops <pod> -- cat /etc/resolv.conf - kubectl get cm -n kube-system coredns -o yaml - Is the nameserver IP correct? Is the CoreDNS config valid?

Hint 4

Common fixes: restart CoreDNS pods (kubectl rollout restart deployment coredns -n kube-system), fix the Corefile if it has syntax errors, or check that the kube-dns Service ClusterIP matches resolv.conf.