KubeCon + CloudNativeCon North America 2019

If you work with Kubernetes, then kubectl is probably one of your most-used tools. Whenever you spend a lot of time working with a specific tool, it is worth to get to know it very well and learn how to use it efficiently. The goal of this lighting talk is not only to make your daily work with Kubernetes more efficient but also more enjoyable!

Custom Resource Definitions (CRDs) and custom controllers (aka the operator pattern) are becoming the main way we extend Kubernetes. From etcd and Prometheus to full-on Kubernetes extensions a la Cluster API and Service Broker API - a lot of teams are building operators.

As the CRD concept is maturing SIG API machinery is adding useful features like validation, defaulting, structural schemas, etc. In more complex extensions with multiple CRDs and multiple controllers, we run into validation and defaulting use cases that can only be modeled with custom validation and mutation webhooks.

This talk will discuss use cases for complex CRD validation and defaulting, incl. common use cases like validating a CRD against another CRD. Furthermore, the speaker will make a point of why to use Open Policy Agent as a common agent to implement such use cases.