I was running minikube until an Alpine image was not able to resolve the DNS for an external network API call.
If you are in the same situation, it could be fixed in this way:
$ kubectl edit configmap coredns -n kube-system
Edit this block:
forward . /etc/resolv.conf{
...
}
as follows:
forward . 8.8.8.8 8.8.4.4{
...
}

