You need to implement the planned change for the AKS1 integration.

The correct configuration is the Secrets Store CSI Driver. The planned change requires AKS1 to integrate with Vault1, which is an Azure Key Vault. Microsoft provides the Azure Key Vault Provider for Secrets Store CSI Driver specifically for this scenario. It enables an AKS cluster to consume Key Vault objects—such as secrets, keys, and certificates—by mounting them into Kubernetes pods through a CSI volume. Microsoft explicitly describes this driver as providing integration between Azure Key Vault and AKS.

A workload identity can be used as an authentication mechanism that allows Kubernetes workloads to authenticate to Azure resources, including Key Vault, but it is not by itself the feature that performs the Key Vault integration requested by the question. In fact, Workload ID is one of several supported identity methods that can be used with the Secrets Store CSI Driver.

Application scaling controls workload capacity and does not provide secret-store integration. Kubernetes RBAC controls authorization to Kubernetes resources but does not connect AKS to Azure Key Vault.

This maps directly to the SC-500 Secure compute domain, which includes implementing and configuring security controls for Azure Kubernetes Service (AKS).