CoreDNS
CoreDNS is an extensible, plugin-based DNS server commonly used in Kubernetes clusters for service and workload name resolution.
Acing the Certified Kubernetes Administrator Exam, Second Edition
CoreDNS is a DNS server and plugin-based system that provides service discovery and name resolution for Kubernetes clusters.
- How it is used
- Provides hostname resolution for pod-to-Service communication and serves as a cluster DNS configuration task for CKA practice.
- How deep it goes
- Works through locating, reconfiguring, scaling, and testing CoreDNS, without detailing its DNS plugins.
- Examples
- Uses a Service CIDR change, pod-level nslookup, replica scaling, a DNS-outage test, and cross-namespace Service lookup.
- What you can do after
- Operate/configure it by changing the DNS Service address and kubelet settings, scaling replicas, and verifying resolution from a pod.
Read how Acing the Certified Kubernetes Administrator Exam, Second Edition explains CoreDNS →
Kubernetes in Action, Second Edition
CoreDNS is an extensible DNS server commonly deployed in Kubernetes clusters to provide service and pod name resolution.
- How it is used
- Provides pod-to-Service name resolution for internal Kubernetes application communication.
- How deep it goes
- Explains lookup names and resolver configuration, but stops short of CoreDNS implementation internals.
- Examples
- Demonstrates curl requests to quiz, cross-namespace names such as quiz.kiada, and pod resolver settings.
- What you can do after
- Apply it via Service DNS names to connect applications without embedding cluster IP addresses.
Read how Kubernetes in Action, Second Edition explains CoreDNS →
Related concepts
- domain name systemuses · The Domain Name System is a distributed, hierarchical naming system that resolves domain names to IP addresses and other network resource records.
- podkind of · A Kubernetes Pod is the smallest deployable unit in Kubernetes, grouping one or more co-located containers that share networking and other resources.
- DNS serverimplements · A DNS server is a network service that answers domain-name queries by returning corresponding DNS records or obtaining them from other DNS servers.
- configmapconfigured by · A ConfigMap is a Kubernetes API resource that stores non-confidential configuration data as key-value pairs for use by workloads and other cluster components.
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