Automating Stateful Applications with Kubernetes Operators

Transcript

1. Automating Stateful Applications with Kubernetes Operators Jan Kleinert jan.kleinert@redhat.com September

   23, 2019

2. @jankleinert 2 Jan Kleinert Developer Advocate, Red Hat twitter/github: @jankleinert

   Hello!

3. @jankleinert 3 What is Kubernetes? An open source orchestration system

   for managing containerized workloads across a cluster of nodes.

4. @jankleinert 4 Pod Deployment DaemonSet ReplicaSet StatefulSet Job Kubernetes objects

   are persistent entities that represent the state of your cluster that you can manage with the K8s API EndPoints Ingress Service ConfigMap Secret StorageClass Namespace NetworkPolicy PersistentVolume Role RoleBinding ServiceAccount Understanding Kubernetes objects

5. @jankleinert 5 Kubernetes Object Definitions kind: Pod apiVersion: v1 metadata:

   name: example-app spec: containers: - name: example image: quay.io/my/app:v1.2.0 [...]

6. @jankleinert 6 Why should you care about operators?

7. @jankleinert 7 Scaling stateless apps: easy

8. @jankleinert 8 $ kubectl scale deploy/staticweb --replicas=3

9. @jankleinert 9 scale up count=1 desired=3 ReplicaSet

10. @jankleinert 10 start count=3 desired=3 ReplicaSet

11. @jankleinert 11 What about apps that store data?

12. @jankleinert 12 Creating a database is easy

13. @jankleinert 13 $ kubectl run db --image=quay.io/my/db

14. @jankleinert 14 Running a database over time is harder

15. @jankleinert 15 ⏣ Resize/Upgrade ⏣ Reconfigure ⏣ Backup ⏣ Healing

16. @jankleinert 16 Every application on any platform must be installed,

    configured, managed, and upgraded over time Patching is critical to security

17. @jankleinert 17 Anything not automated is slowing you down

18. @jankleinert 18 If only Kubernetes knew...

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20. @jankleinert 20

21. @jankleinert 21 Operators are automated software managers that deal with

    installation and lifecycle of Kubernetes applications

22. @jankleinert 22 1. Application-specific custom controllers 2. Custom resource definitions

    (CRD) Extending the Kubernetes API

23. @jankleinert 23 The Operator Pattern K8S API CUSTOM RESOURCE &

    MY APP STATE WATCH EVENTS RECONCILE MY K8S APPLICATION Controller

24. @jankleinert 24 Application-Specific Controllers

25. @jankleinert 25 Custom Resource Definition (CRD) kind: ProductionReadyDatabase apiVersion: database.example.com/v1alpha1

    metadata: name: my-production-ready-database spec: clusterSize: 3 readReplicas: 2 version: v4.0.1 [...]

26. @jankleinert 26 { }

27. @jankleinert 27 What is etcd? Example: etcd Operator • distributed

    key-value store • primary datastore of Kubernetes • stores and replicates all Kubernetes cluster state

28. @jankleinert 28 Example: etcd Operator kind: EtcdCluster apiVersion: etcd.database.coreos.com/v1beta2 metadata:

    name: example-etcd-cluster spec: size: 3 version: "3.1.0"

29. @jankleinert 29 Example: etcd Operator

30. @jankleinert 30

31. @jankleinert 31 https://learn.openshift.com/operatorframework/ Try It! Hands-On Operator Tutorials

32. @jankleinert 32 Use Operators Today OperatorHub.io is a home for

    the Kubernetes community to share Operators. Find an existing Operator or list your own today.

33. @jankleinert 33 https://github.com/operator-framework

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37. @jankleinert 37 Operator Maturity Model Phase I Phase II Phase

    III Phase IV Phase V Basic Install Automated application provisioning and configuration management Seamless Upgrades Patch and minor version upgrades supported Full Lifecycle App lifecycle, storage lifecycle (backup, failure recovery) Deep Insights Metrics, alerts, log processing and workload analysis Auto Pilot Horizontal/vertical scaling, auto config tuning, abnormal detection, scheduling tuning

38. @jankleinert 38 https://github.com/operator-framework https://coreos.com/operators/ https://operatorhub.io https://coreos.com/blog/introducing-operator-framework https://learn.openshift.com/operatorframework/ Resources

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