Posts in Kubernetes

Understanding the network plumbing that makes Kubernetes pods and services work

This morning I wanted to better understand how requests to ClusterIPs get routed to Kubernetes pods. Properly functioning networking is critical to Kubernetes and having a solid understanding of what happens under the covers makes debugging problems much, much easier. To get started with my studies I fired up five kuard pods: I created 5 pods so one would hopefully be placed on each worker node. Once the pods finished creating I exposed the pods to the cluster with the kubectl expose command: Behind the scenes kube-proxy uses iptables-save and iptables-restore to add rules…