Kubernetes Networking: CNI and Network Policies

Kubernetes (K8s) is a powerful, flexible and portable open source framework for distributed containerized applications delivery and management. An important part of the services provided by most Kubernetes clusters is the containers’ networking stack. In most cases and for many applications it “just works”, but this seeming simplicity is backed by a complex stack of technologies that provide many capabilities beyond the basics.

In this meetup, Oleg, CTO at Kublr, will show how Kubernetes networking stack works, describe main components, interfaces and extensibility options.

We will cover:

- general notions of Kubernetes networking - Pods and Network Policies
- implementation of Kubernetes networking - CNI, CNI plugins, and Linux network namespaces
- some Kubernetes CNI providers: Calico, Weave, Flanel, and Canal
- K8S networking extensibility for advanced and “exotic” use-cases with Multus CNI plugin as an example