A Case Study on Five Maturity Levels of A Kubernetes Operator

Deploying distributed applications using their Operators in a containerized platform on the state-of-art cloud orchestration tooling, such as Kubernetes, has truly become widely accepted. However, the quality of an Operator has a significant impact on a few core metrics of the application, such as its availability, consistency, and quality of service. This paper introduces the Kubernetes Operator maturity model and its five maturity levels, and then gives a demonstration on how a demo Kubernetes Operator is capable of reaching all the five levels respectively by using an example Operator named New Visitors Site Operator. Finally, an experiment illustrating the capability of the example Operator's auto-scaling functions to improve the application performance is presented. This example Operator will enable developers and researchers to design containerized applications with more enhanced features. The code is available at https://github.com/ringdrx/visitors-operator.