OVN-Kubernetes: Software-Defined Networking for Kubernetes
Shriira Press
How OVN-Kubernetes turns Kubernetes networking intent into virtual switches, routers, and flows — the CNI that powers OpenShift and demanding telco clusters.
Welcome to OVN-Kubernetes: Software-Defined Networking for Kubernetes.
OVN-Kubernetes is a CNI network plugin that gives Kubernetes a complete, programmable network built on Open Virtual Network (OVN) and Open vSwitch (OVS). Rather than stitching pods together with host routes and iptables rules, it models the cluster as a software-defined network of logical switches, routers, and load balancers, then compiles that model down to OpenFlow on every node. This book starts with the problem Kubernetes networking poses and the OVN and OVS foundations the plugin rests on, then walks through its architecture — the cluster manager, the per-node controller, the northbound and southbound databases, ovn-northd, and ovn-controller — and the journey a pod or service takes from an API object to a flow in the datapath. From there it covers the pieces that make a real cluster work: pod connectivity and the cluster router, services and load balancing as a kube-proxy replacement, NetworkPolicy enforced through ACLs, the gateway modes that carry north-south traffic, the egress controls EgressIP, EgressFirewall, and EgressQoS, multi-homing with secondary networks, and finally operating the plugin in practice. It is the default network for OpenShift and a CNCF project trusted by enterprise and telco users.
This title is part of the ShriIra library and is free to read in full, right here — our small contribution to making world-class knowledge easy to reach.
A note on reading it: open the Contents menu at the top of the reader to jump between chapters, use the Aa menu to set a comfortable text size, theme (light, sepia, or night), and single- or two-page layout. Your place is saved automatically, so you can always pick up where you left off.
We hope it serves you well.
— Shriira Press