Since the beginning of time, declarative APIs have been driving everything that can happen inside a Kubernetes cluster. Predefined CRDs, operators defining custom CRDs, everything is about declarative APIs. Write your YAML once, deploy it, forget it. That’s how you create a cluster, that’s how you deploy your workload. But is it, for real, as simple as it sounds? How do you bring declarativeness to the imperative world? In the current state of things, host networking is one huge imperative nightmare. So how to happily marry an old-school Network Manager and brand new Kubernetes API? In this session we will demonstrate how NMState provides you with a Declarative Network API, finally allowing you to manage host networking in a declarative manner. To make it more entertaining, we will show you how the Kubernetes cluster with NMState Operator manages networking on the nodes it deploys. It may sound like a chicken and egg situation, but trust us, it is not. Last but not least, we show how it protects itself from applying destructive network changes potentially taking your cluster down. Join us and create the most complex network topologies on the fly.