CoreDNS and Kubernetes DNS: What Actually Happens When a Pod Looks Up a Name

Tue, 30 Jul 2024 09:00:00 +0000

For something so fundamental, Kubernetes DNS is astonishingly easy to take for granted. You write http://my-service in your code, it resolves, traffic flows, everyone goes home. Then one day a pod can’t reach another service, nslookup returns SERVFAIL, and you discover you have no idea what was happening under the hood the entire time. I have been that person at 1am, and I would rather you weren’t.

So let’s follow a single DNS lookup end to end. No magic, just a chain of unremarkable Linux mechanics that happen to be wired together rather cleverly.

CoreDNS - Tag - vo.rs

CoreDNS and Kubernetes DNS: What Actually Happens When a Pod Looks Up a Name