CoreDNS is the Domain Name System (DNS) server commonly used inside Kubernetes. It turns Service names such as orders.default.svc into the Service address, so pods can find each other without hard-coded IP addresses. Plugins extend that name-resolution behavior; kube-dns is the older Kubernetes DNS implementation it commonly replaces.
kubernetes #externalname #namespaces #dns #k8s
These snippets are command-line shortcuts. A Kubernetes namespace groups resources and scopes their names; a custom resource definition (CRD) adds a new resource type to the Kubernetes application programming interface (API).
In Kubernetes, the Container Network Interface (CNI) plugin connects pods. A Linux network namespace is an isolated view of interfaces and routes managed by the operating-system kernel; traffic between nearby pods can stay on the same machine.