As I was going through CKA Mock Exam 2, I encountered an issue trying to resolve nginx-resolver-service. I then tried to resolve the kubernetes service but it too failed.
Thinking it was a faulty busybox instance, I deleted and recreated it. Same issue.
Resolved it by killing the 2 coredns pods in kube-system namespace and after they restarted, DNS was fine - weird. Before killing the pods, I checked their logs but there was nothing in there - just 4-5 log lines.
Just thought I’d mention it as a heads up to others in the same predicament.