#Creating a BucketClass for MinIO

MinIO integrates with Kubernetes through the Container Object Storage Interface (COSI) to provide scalable, S3-compatible object storage for analytics, backup & restore, and ML/AI workloads. Before provisioning buckets, define a BucketClass.

A BucketClass is a template resource that sets the storage driver, the authentication Secret, and the deletion policy applied to all buckets created from it.

#Prerequisites

#Step 1 - Prepare a MinIO Cluster

Ensure that a MinIO cluster is installed and accessible. Follow the MinIO installation documentation to deploy and configure your MinIO environment.

#Step 2 - Prepare the Credential Secret

COSI retrieves MinIO credentials from a Kubernetes Secret. Collect the following values:

• Endpoint - e.g. http://minio.minio-system.svc or https://minio.example.com:9000
• AccessKey
• SecretKey

Create the Secret in the target namespace and label it for UI discovery:

kubectl create secret generic minio-credentials -n <YOUR_NAMESPACE> \
  --from-literal=Endpoint=http://<YOUR_MINIO_ENDPOINT> \
  --from-literal=AccessKey=<YOUR_ACCESS_KEY> \
  --from-literal=SecretKey=<YOUR_SECRET_KEY>

kubectl label secret minio-credentials -n <YOUR_NAMESPACE> app=minio

Important: The label app=minio is required for the platform UI to list the Secret.

Note: Key names are case-sensitive and must be exactly Endpoint, AccessKey, and SecretKey.

If you prefer GitOps, you can define the Secret declaratively:

apiVersion: v1
kind: Secret
metadata:
  name: minio-credentials
  namespace: <YOUR_NAMESPACE>
  labels:
    app: minio
type: Opaque
stringData:
  Endpoint: http://<YOUR_MINIO_ENDPOINT>
  AccessKey: <YOUR_ACCESS_KEY>
  SecretKey: <YOUR_SECRET_KEY>

#Step 3 - Create the BucketClass

#Option 1 - UI Workflow

1. Navigate to Storage → Object StorageClass and click Create Object StorageClass.

2. Select MinIO Object Storage as the driver.

3. Configure the following fields:

   • Deletion Policy - How the underlying bucket is handled when its BucketClaim is deleted (default: Delete).
   • Secret - Choose the Secret created in Step 2 (only Secrets with app=minio are shown).
   • Allocate Projects - Optional: restrict usage to specific projects.

4. Click Create.

#Option 2 - YAML (GitOps-friendly)

Create minio-bucketclass.yaml. The example below uses the MinIO COSI driver and points to a Secret with the correct Secret references.

apiVersion: objectstorage.k8s.io/v1alpha1
kind: BucketClass
driverName: minio.objectstorage.k8s.io
metadata:
  labels:
    project.cpaas.io/name: null
    project.cpaas.io/ALL_ALL: "true"
  name: minio-bucket-class
  annotations:
    cpaas.io/display-name: BucketClass for MinIO
    cpaas.io/access-mode: ""
    cpaas.io/features: ""
parameters:
  providerSecretName: <your-secret-name>
  providerSecretNamespace: <your-secret-namespace>
deletionPolicy: Delete

Apply the manifest:

kubectl apply -f minio-bucketclass.yaml

#Verification and Next Steps

Verify the BucketClass:

kubectl get bucketclass

Once the BucketClass is ready, create Bucket or BucketClaim resources referencing it to provision S3-compatible object storage backed by MinIO.