Website operator

This repository contains an example schema of an operator written in .Net. You could use it in order to start develop your first Kubernetes operator!

The schema contains three elements:

Controller (a.k.a. Reconciler)
Entity
Finalizer

The controller is going to manage the "reconcile" step. It will watch over the observed resources and takes care of being sure that the k8s cluster state and the desired state are the same.

The entity described the state that should be observed by the controller.

The finalizer has the responsibility of dispose unused resources.

💪🏻 Working software exercises

You should start from this schema and implement the following feature:

feat n.1: Create a Pod with image nginx everytime a new custom resource of type website has been created
feat n.2: When a custom resource has been deleted, remove the linked resources (Pod)
feat n.3: When a new custom resource has been created or updated, the operator should deploy a deployment manifest and take the number of replicas from the new custom resource
feat n.4: Show time: 🎉 Create a NodePort service for that deployment and retrieve the public ip address.
feat n.5: When the pod starts, update the default nginx index.html and put inside a short description from the custom resource

How to run in local env

If you want to test the operator locally you could easily run it in a local minikube instance.

Build operator image:

docker build -t javaoperator .

Load the image in your local minikube cluster

minikube image load javaoperator

Apply it:

kubectl apply -k kubernetes-charts

Notes

(*) Reconciles: it stands for the act of the operator to edit (reconcile) the status of the kubernetes cluster as we want (looking at the custom resource)

Custom Resource Example

apiVersion: "intre.it/v1" kind: WebSite metadata: name: demo-site spec: shortDescription: "An amazing website!" url: www.demosite.com webSiteName: demo-site

https://docs.openshift.com/container-platform/4.11/operators/operator_sdk/java/osdk-java-tutorial.html https://github.com/kubernetes-client/java/tree/b42fae2b5437836f8c0254d8f19f3a7ba9ebd503/kubernetes/docs