How Do I Build a Kubernetes Storage.k8s.io Storageclass?

Introduction

In Kubernetes, a StorageClass provides a way for administrators to define different “classes” of storage. This abstraction allows users to request storage with specific characteristics, such as performance and availability, without needing to understand the underlying storage infrastructure. When a PersistentVolumeClaim (PVC) is made, it can specify a desired StorageClass, which dictates how the storage should be provisioned.

Creating a StorageClass

To create a Kubernetes StorageClass, we need to define a YAML manifest that specifies its parameters, the provisioner, and other configuration settings. Here’s how you can define a StorageClass using infrastructure as code with Pulumi:

import * as pulumi from "@pulumi/pulumi";
import * as kubernetes from "@pulumi/kubernetes";

const example = new kubernetes.storage.v1.StorageClass("example", {
    metadata: {
        name: "example-storage-class",
    },
    provisioner: "kubernetes.io/aws-ebs",
    parameters: {
        type: "gp2",
    },
});
export const storageClassName = example.metadata.apply(metadata => metadata.name);

Step-by-Step Explanation

1. Provider Configuration: Ensure you have access to your Kubernetes cluster. In this example, access is configured via the kubeconfig file at ~/.kube/config.

2. Resource Definition:

   • Define a resource of type kubernetes_storage_class named example.
   • Specify the metadata with a name for the StorageClass.
   • Set the provisioner to determine how the storage is provisioned. In this example, it’s set to kubernetes.io/aws-ebs.
   • Include parameters that are specific to the provisioner, such as type: "gp2" for AWS EBS.

3. Output: Export the name of the created StorageClass for easy reference after deployment.

Key Points

• A StorageClass allows dynamic provisioning of storage resources.
• The provisioner field is crucial as it defines the storage backend.
• Parameters should be tailored to the chosen provisioner to optimize storage characteristics.
• Infrastructure as code ensures that your StorageClass definitions are version-controlled and can be easily managed.

Conclusion

By defining a StorageClass using infrastructure as code, you can streamline storage management in Kubernetes, ensuring consistency and scalability. This approach not only simplifies storage provisioning but also integrates storage management into your overall infrastructure strategy, making it easier to maintain and evolve over time.