Kubernetes Operator

Giriş

Açıklaması şöyle. Yani Kubernetes Operator gerçekleştirimleri CustomResource tanımlar ve kullanırlar

The way Kubernetes provisions pods and starts services does not align with the operational steps needed to care and feed for a Cassandra cluster — there’s a gap that must be bridged between Kubernetes workflows and Cassandra runbooks.

Kubernetes provides a number of built-in resources — from a simple building block like a Pod, to higher-level abstractions such as a Deployment. These resources let users define their requirements, and Kubernetes provides control loops to ensure that the running state matches the target state. A control loop takes short incremental actions to nudge the orchestrated components towards the desired end state — such as restarting a pod or creating a DNS entry. However, domains like distributed databases require more complex sequences of actions that don’t fit nicely within the predefined resources. This is great, but not everything fits nicely within a predefined resource.

Kubernetes Custom Resources were created to allow the Kubernetes API to be extended for domain-specific logic, by defining new resource types and controllers. OSS frameworks like operator-SDK, kubebuilder, and juju were created to simplify the creation of custom resources and their controllers. Tools built with these frameworks came to be known as Operators.

How To Build a Kubernetes Operator

Açıklaması şöyle

If your goal after reading this is to create a Kubernetes Operator, you need to know that there are already some frameworks that will make your life easier at that task.

Tools like Kopf, kubebuilder, metacontroller , or even the CNCF Operator Framework will provide you the tools and the everyday tasks to start focusing on what your operator needs to do, and they will handle the main daily tasks for you.

Mevcut Operator'lar

OperatorsHub sayfasında bulunabilir

Java Operator SDK

Bir örnek burada

OraOperator

Bu projeyi ilk olarak burada gördüm