Blog
Thoughts on engineering, design, and building great products.
CoreDNS: Calling Each Other by Name in the Cluster
Pods can already talk by IP, but a pod's IP changes every time it's reborn, so no one hard-codes them. CoreDNS fills that gap: it runs as a workload right in the cluster, sits behind a Service at exactly the 10.32.0.10 that kubelet has been pointing pods at, and resolves Service names into ClusterIPs. This article deploys CoreDNS by hand — RBAC, ConfigMap, Deployment, Service — then tests a pod resolving both internal and external names.
DNS: Resolving Domain Names
A deep dive into DNS — the system that translates domain names into IPs. Understand the root/TLD/authoritative hierarchy, recursive resolvers, the step-by-step resolution flow, record types (A, CNAME, MX, NS, TXT), and the role of TTL/cache. Observed live with dig.