What is CoreDNS?
The default DNS server in Kubernetes clusters for service discovery.
CoreDNS is the default DNS server deployed in Kubernetes clusters (since 1.13). It provides DNS-based service discovery: every Service gets a DNS entry like my-service.my-namespace.svc.cluster.local. Pods use this to find other services without hardcoding IPs. CoreDNS is highly configurable through a Corefile. Common issues include DNS timeout under high load — solvable by scaling CoreDNS replicas or adjusting ndots settings.
Deep Dive Guide
kubernetes coredns resolution failures fix
Related Terms
More Kubernetes Terms
Admission Controller
A Kubernetes plugin that intercepts API requests before objects are persisted.
Auto Scaling
Automatically adjusting the number of compute resources based on demand.
ClusterIP
The default Kubernetes Service type that exposes a service on an internal cluster IP.
ConfigMap
A Kubernetes object for storing non-sensitive configuration data as key-value pairs.
Controller Manager
Kubernetes control plane component running control loops to maintain desired state.
CRD (Custom Resource Definition)
A Kubernetes extension mechanism for defining custom object types.
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