
* Uplift the CoreDNS image to 1.7.0 (aligning to k8s v1.20) [0] * Update the Corefile based on corefile-tool migration [1] Note that the previously-deprecated "upstream" option is removed in 1.7.0 [2], and if not removed from the Corefile, will cause the pods to crashloop. 0: https://github.com/coredns/deployment/blob/master/kubernetes/CoreDNS-k8s_version.md 1: https://github.com/coredns/corefile-migration/tree/master/corefile-tool 2: https://github.com/coredns/coredns/pull/3737 Change-Id: I03882240e8335f09956e412345e783e9a897ed9a