When using the shared secret authentication method, Portworx requires the Kubernetes secret containing the authentication token to be located in the same namespace as the application that is requesting storage. The Portworx StorageClass is configured with parameters (px.io/secret-name and px.io/secret-namespace: ${pvc.namespace}) that instruct the CSI provisioner to dynamically look for the secret in the namespace where the PersistentVolumeClaim (PVC) is being created. This ensures that only applications within that specific namespace can use the secret to authenticate and provision Portworx volumes, adhering to Kubernetes' namespaced security model.

B. In the 'default' namespace: This is incorrect. Placing the secret in the default namespace would not make it accessible to applications in other namespaces without additional, non-standard configuration.

C. In the same namespace as the Portworx installation: This is incorrect. Storing the secret in the Portworx system namespace (e.g., kube-system) would require complex cross-namespace RBAC permissions for every application, which is not the standard procedure.

1. Portworx Enterprise Documentation

"Security -> With Kubernetes -> Configure Portworx security with Kubernetes secrets": This document explicitly states

"Create a Kubernetes secret in the namespace where you will be creating your PVCs." It provides the example command kubectl -n create secret generic px-secret ... to create the secret in the target application namespace.

2. Portworx Enterprise Documentation

"Storage Operations -> Storage Provisioning in Kubernetes -> Dynamic Provisioning": This page details the StorageClass parameters. It shows the use of px.io/secret-namespace: ${pvc.namespace}

which confirms that the provisioner resolves the secret's namespace to be the same as the PVC's namespace at the time of creation.