Introduction

In this tutorial, we will learn how to set up Storage Classes in Kubernetes for dynamic provisioning. This process allows storage volumes to be created on-demand, simplifying storage management in your Kubernetes cluster.

By the end of this tutorial, you should be able to:

• Understand what Storage Classes and dynamic provisioning are
• Create a StorageClass
• Use a StorageClass for dynamic provisioning

Prerequisites:

• Basic understanding of Kubernetes
• A running Kubernetes cluster
• Familiarity with the kubectl command-line tool

Step-by-Step Guide

A StorageClass in Kubernetes is an abstraction of storage provisioner, which defines the type of storage and the strategy to use when a storage claim is issued. Dynamic provisioning means that Kubernetes can create storage volumes on demand based on StorageClasses.

The following steps will guide you through the process:

1. Define a StorageClass

Create a YAML file (for example, my-storage-class.yaml) with the following content:

yaml apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: my-storage-class provisioner: kubernetes.io/aws-ebs parameters: type: gp2

This StorageClass uses the aws-ebs provisioner and will create gp2 volumes.

1. Create the StorageClass

Apply the YAML file with the kubectl command:

shell kubectl apply -f my-storage-class.yaml

1. Use the StorageClass

When you create a Persistent Volume Claim (PVC), specify the StorageClass:

yaml apiVersion: v1 kind: PersistentVolumeClaim metadata: name: my-pvc spec: accessModes: - ReadWriteOnce resources: requests: storage: 1Gi storageClassName: my-storage-class

With this PVC, Kubernetes will dynamically provision a 1Gi gp2 volume on AWS EBS.

Code Examples

1. Example of creating a StorageClass

shell kubectl create -f - <<EOF apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: my-storage-class provisioner: kubernetes.io/aws-ebs parameters: type: gp2 EOF

This command creates a StorageClass named my-storage-class that uses the Amazon EBS volume plugin and creates gp2 volumes.

1. Example of using the StorageClass

shell kubectl create -f - <<EOF apiVersion: v1 kind: PersistentVolumeClaim metadata: name: my-pvc spec: accessModes: - ReadWriteOnce resources: requests: storage: 1Gi storageClassName: my-storage-class EOF

This command creates a PVC named my-pvc that requests a single ReadWriteOnce volume of 1Gi. Kubernetes will use the my-storage-class StorageClass to dynamically provision the volume.

Summary

In this tutorial, we learned:

• What Storage Classes in Kubernetes are
• How to create a StorageClass
• How to use a StorageClass for dynamic provisioning

Next, you should try to create different types of StorageClasses and use them in PVCs. The Kubernetes documentation is a great resource to learn more.

Practice Exercises

1. Create a StorageClass with the kubernetes.io/gce-pd provisioner

Try to create a StorageClass that uses the gce-pd provisioner and pd-ssd disks. Apply it and check that it is available in your cluster.

1. Create and use a PVC with your new StorageClass

Create a PVC that requests 10Gi storage and uses your new StorageClass. After applying it, check that Kubernetes dynamically provisioned the volume.

Solutions and explanations to these exercises can be found in the Kubernetes documentation and by using the kubectl describe command. Happy coding!