Why is CoreDNS Resolving via Upstream Google DNS (8.8.8.8)?

Problem

CoreDNS is resolving all cluster DNS queries via the upstream Google DNS address – 8.8.8.8. Why? Is this the expected default behavior?

Environment

Platform9 Managed Kubernetes - All Versions
Docker

Answer

If no nameservers are specified within /etc/hosts – inherited from the node – Docker will default to using Google DNS (8.8.8.8) as the upstream resolver.

Additional Information

Docker – Container Networking

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