Unlocking the Secrets of Kubernetes Networking: A Practical Guide for Top-Level Engineers

The article discusses the basics of Kubernetes networking, its model, challenges, and troubleshooting techniques. It explains how pods in Kubernetes can communicate with each other due to their unique IP addresses and a flat network model. The Container Network Interface (CNI) is highlighted as a standard interface specification for network plugins in container orchestration systems like Kubernetes. Four major areas where issues arise in Kubernetes networking are identified: pod-to-pod communication, container-to-container communication, pod-to-service communication, and external-to-service communication. Various methods to facilitate external communication to a Kubernetes cluster are also discussed. Troubleshooting techniques for debugging networking issues in Kubernetes include using the kubectl exec command to execute commands inside a running container, the kubectl logs command to retrieve the logs of a container, and third-party tools like Ksniff for network packet capture and analysis.