Kubernetes (K8S) runs a set of default controllers to ensure the desired state (goal or expected configuration run time) of the Cluster.
Examples:
- Replication Controller is responsible for maintaining the correct number of pods in a Cluster.
- Node Controller is responsible for noticing and responding when nodes go down.
Kubernetes 1.7 has added an important feature called Custom Controllers. It enables developers to extend and add new K8S native functionalities that work as an extension of Control Plane.
What is an Operator?
An Operator is a K8S Custom controller (+ Additional properties) to run a K8S application, with human operational knowledge baked in. It’s a method of packaging, deploying and managing K8S applications. They are smarter, scalable, standardized and have direct access to K8S API.
IT Automation is not new. But why is Kubernetes operator a game changer?
It manages Infrastructure, Applications and Operations all together. They do repeat install of software, upgrade, constant health checks, encapsulate operational knowledge and share the accumulated knowledge with human users and applications.
In IT configuration management, we divide the provisioning of software and…
