Kubernetes Operators automate the creation, configuration, and management of instances of Kubernetes-native applications. A Kubernetes-native application is an application that is both deployed on Kubernetes and managed using the Kubernetes APIs and kubectl tooling.
The resources below cover information about what Operators are and how they work, as well as how to build Operators using the Operator Framework and Operator SDK.
There are several self-paced interactive learning scenarios available here.
Within RHPDS, the catalog item is in the Workshops category and is called OCP4 Workshop - Build an Operator.
Details on the workshop content as well as full instructions on how to deploy and run the workshop once the cluster is available are here.
The source code for the workshop guide is here.
Recording of the Automating Stateful Applications with Kubernetes Operators talk from DevOps Days Boston 2019.