Networking is a vital concern for production-level operations. At a service level, we need a reliable way for our application components to find and communicate with each other. Introducing containers and clustering into the mix makes things more complex as we now have multiple networking namespaces to bear in mind. Communication and discovery now becomes a feat that must navigate container IP space, host networking, and sometimes even multiple data center network topologies.

Kubernetes benefits here from getting its ancestry from the clustering tools used by Google for the past decade. Networking is one area where Google has outpaced the competition with one of the largest networks on the planet. Earlier, Google built its own hardware switches and Software-defined Networking (SDN) to give them more control, redundancy, and efficiency in their day-to-day network operations. Many of the lessons learned from running and networking two billion containers per week have been distilled into Kubernetes, and informed how K8s networking is done.