This document discusses deploying software-as-a-service (XaaS) applications using operators on Kubernetes. It defines operators as collections of custom resource definitions and controllers that manage the lifecycle of those resources. Operators can deploy applications and dependencies within or outside the Kubernetes cluster. The document provides examples of when to use operators for internal resources like databases, as well as managed cloud services. It also discusses where to find operators and how to deploy common ones like Elasticsearch, AWS services, and Kafka.

1. Deploying XaaS Using
Operators on Kubernetes
Jeff Spahr
Sr Engineering Manager
Lenovo

2. What is the Operator Pattern?
● An operator is a collection of Custom Resource Definitions (CRDs) and a
controller to manage the lifecycle of those CRDs
● The controller handles all the application deployment and management logic
● Abstracts away higher level resources
● Go from zero to a working application faster
● Avoid spending time on how to properly represent this app in a Deployment or
StatefulSet
● https://kubernetes.io/docs/concepts/extend-kubernetes/operator/

3. Operators - Not just for resources inside your cluster
● An operator can run things like databases or message queues as pods inside
the cluster
● An operator can also be used to control external services from cloud
providers or anything with an api outside of the cluster.

4. When to use an Operator? Internal Resources
● You want to provide XaaS to your application developers in a K8s cluster
● You run clusters on prem and do not have access to common managed
services
● You run hybrid cloud workloads in K8s, and you’re willing to take on more
operational overhead in order to abstract away your underlying environment

5. When to use an Operator? Internal or External to K8s
● You want to deploy all of your application and dependencies using K8s via
Kubernetes Resource Modeling (KRM)

6. When NOT to use an Operator?
● Cloud only and you have access to managed services in your cloud provider
● Running K8s in AWS and you need a relational database? Use RDS
● Running K8s in AWS and you need a message queue? Use SQS
● Running K8s in AWS and you need a NoSQL database? Use DynamoDB
● Exception - Use an operator to deploy managed services!

7. Where to find operators?
● OperatorHub.io
● Google “kafka kubernetes operator”
● Pay attention to how active the project is
● What license is it using?

8. Deploy an Operator

9. Elasticsearch - ECK
https://www.elastic.co/guide/en/cloud-on-k8s/current/k8s-installing-eck.html
kubectl create -f
https://download.elastic.co/downloads/eck/1.8.0/crds.yaml
kubectl apply -f
https://download.elastic.co/downloads/eck/1.8.0/operator.yaml
kubectl get secret elasticsearch-sample-es-elastic-user -n ato-demo
-o go-template='{{.data.elastic | base64decode}}'

10. AWS Controller for K8s
https://aws-controllers-k8s.github.io/c
ommunity/docs/user-docs/install/

11. Crossplane
https://crossplane.io/docs/v1.4/
● Multiple providers
○ AWS
○ GCP
○ Azure
● Composite resources to offer
opinionated configuration

12. Kafka - Strimzi
https://strimzi.io/docs/operators/latest/quickstart.html
kubectl create ns kafka
kubectl apply -f install/cluster-operator/ -n kafka

13. Thank you!
GitHub LinkedIn I’m Hiring

14. Undo
kubectl delete -f elasticsearch.yaml
kubectl delete -f kibana.yaml
kubectl delete -f bucket.yml