Diegolden

Topic 4: DNS

2 min read

Topic 4: DNS

Official baseline: (The Kubernetes Authors, 2026a, 2026b). My working version: DNS turns Kubernetes objects into names humans and applications can depend on.

Mental Model

DNS turns Kubernetes objects into names humans and applications can depend on.

Notes

  • Service DNS names are often the cleanest internal API boundary.
  • Pod DNS exists, but Services are usually the application-level abstraction.
  • CoreDNS health is cluster health for most workloads.

Homelab Angle

Practice with nslookup from a debug Pod. DNS issues are easier when you verify from inside the cluster.

Verify It

  • Read the object status before changing the manifest.
  • Check events for the controller or node that is actually complaining.
  • Confirm the official source linked below still matches the cluster version you run.

Common Failure Modes

  • Treating the YAML object as the system, instead of one input to a reconciliation loop.
  • Debugging from outside the cluster when the failure only exists inside cluster networking or node state.
  • Forgetting that Kubernetes version, addon version, and runtime behavior are linked.

Sources

  • DNS for Services and Pods - source path: content/en/docs/concepts/services-networking/dns-pod-service.md, commit 8cc9e19b8eec8d5cf49eacd66f86a81648edb1a0.
  • Kubernetes Components - source path: content/en/docs/concepts/overview/components.md, commit 8cc9e19b8eec8d5cf49eacd66f86a81648edb1a0.
  • Kubernetes documentation is licensed under CC BY 4.0; these notes are original commentary and link back to the official source.
The Kubernetes Authors. (2026a). DNS for Services and Pods. https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/
The Kubernetes Authors. (2026b). Kubernetes Components. https://kubernetes.io/docs/concepts/overview/components/

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