Configuring CoreDNS
Kubernetes used to have kube-dns as its default cluster DNS service, but starting from version 1.11, it uses CoreDNS. Also, it gets pre-deployed by most of the managed Kubernetes offerings, including EKS, that we use in this book.
For the other Kubernetes managed services that still use kube-dns, such as GKE, we recommend referring to the official documentation of kube-dns.
CoreDNS is very flexible as it is modular and pluggable. It has a rich set of plugins that can be enabled to enhance DNS functionalities. This is why it is powerful and generally preferred over kube-dns and other Kubernetes DNS solutions. To learn more about the supported plugins, please refer to the following list: https://coredns.io/plugins/.
During the cluster's lifetime, you need to control CoreDNS configuration as code, its periodic updates, and include all of this within the cluster's deployment pipeline. Also, you will need to optimize your cluster DNS performance and...
