Master the plugin-based DNS server that powers Kubernetes service discovery — Corefile, plugins, and all.

Welcome to CoreDNS: Flexible DNS for Kubernetes and Beyond.

CoreDNS is the flexible, plugin-based DNS server that is the default for Kubernetes — the component that lets one Pod find another by name. This free book teaches it from the ground up: a DNS fundamentals refresher, CoreDNS's tiny-core plugin-chain architecture, the Corefile configuration language, the essential plugins (kubernetes, forward, cache, errors, log, health, rewrite and more), how it powers Kubernetes service discovery and the cluster naming scheme, performance and scaling with caching, ndots, and NodeLocal DNSCache, securing DNS with encryption, access control, and DNSSEC, writing your own plugins, and operating and troubleshooting CoreDNS in production. Ten focused chapters with real Corefiles and clear diagrams that make the name-resolution layer everything depends on something you can configure and debug with confidence.

This title is part of the ShriIra library and is free to read in full, right here — our small contribution to making world-class knowledge easy to reach.

A note on reading it: open the Contents menu at the top of the reader to jump between chapters, use the Aa menu to set a comfortable text size, theme (light, sepia, or night), and single- or two-page layout. Your place is saved automatically, so you can always pick up where you left off.

We hope it serves you well.

— Shriira Press

Contents

1. Chapter 1 — What CoreDNS Is
2. Chapter 2 — DNS Fundamentals
3. Chapter 3 — Architecture and the Plugin Chain
4. Chapter 4 — The Corefile
5. Chapter 5 — Essential Plugins
6. Chapter 6 — CoreDNS in Kubernetes
7. Chapter 7 — Performance and Scaling
8. Chapter 8 — Security
9. Chapter 9 — Extending CoreDNS
10. Chapter 10 — Operating CoreDNS and Putting It Together