Harden Dynamic Resource Allocation in Your Cluster

This page shows cluster administrators how to harden authorization for Dynamic Resource Allocation (DRA), with a focus on least-privilege access for ResourceClaim status updates.

Before you begin

• You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:

  • iximiuz Labs
  • Killercoda
  • KodeKloud

  To check the version, enter kubectl version.

• Dynamic Resource Allocation is configured in your cluster.
• You can edit RBAC resources and restart or roll out DRA components.

Identify DRA components that write status

Document which identities (usually ServiceAccounts) update ResourceClaim status in your cluster. Typical writers are:

• kube-scheduler or a custom allocation controller
• node-local DRA drivers
• multi-node DRA status controllers

Grant least-privilege permissions for synthetic subresources

Starting in Kubernetes v1.36, DRA status updates require synthetic subresource permissions in addition to resourceclaims/status.

Grant scheduler and allocation-controller permissions

Apply a role that allows binding-related updates:

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: dra-binding-updater
rules:
  - apiGroups: ["resource.k8s.io"]
    resources: ["resourceclaims/status"]
    verbs: ["get", "patch", "update"]
  - apiGroups: ["resource.k8s.io"]
    resources: ["resourceclaims/binding"]
    verbs: ["patch", "update"]

Grant node-local driver permissions

Use node-aware verbs for node-local drivers:

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: dra-node-driver-status-updater
rules:
  - apiGroups: ["resource.k8s.io"]
    resources: ["resourceclaims/status"]
    verbs: ["get", "patch", "update"]
  - apiGroups: ["resource.k8s.io"]
    resources: ["resourceclaims/driver"]
    verbs: ["associated-node:patch", "associated-node:update"]
    resourceNames: ["dra.example.com"]

Grant multi-node controller permissions only when needed

Use arbitrary-node:* only for components that must update from any node:

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: dra-multinode-status-updater
rules:
  - apiGroups: ["resource.k8s.io"]
    resources: ["resourceclaims/status"]
    verbs: ["get", "patch", "update"]
  - apiGroups: ["resource.k8s.io"]
    resources: ["resourceclaims/driver"]
    verbs: ["arbitrary-node:patch", "arbitrary-node:update"]
    resourceNames: ["dra.example.com"]

Bind roles to explicit identities

Create ClusterRoleBinding objects for each component identity, and avoid sharing a broad role across unrelated DRA components.

Restrict resourceclaims/driver rules with resourceNames where possible so an identity can only write status for the specific DRA driver it operates.

Validate and monitor

1. Verify each identity has only the required verbs and subresources.
2. Confirm DRA status updates work after rollout.
3. Watch API server audit events for denied resourceclaims/binding and resourceclaims/driver requests.

What's next

• Hardening Guide - Dynamic Resource Allocation
• Securing a Cluster
• Authorization