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Module: Storage

Part of: eks-recon Purpose: Detect storage configuration - CSI drivers, StorageClasses, PVCs, snapshots

Table of Contents

• Prerequisites
• Detection Strategy
• Detection Commands
  • 1. CSI Drivers
  • 2. StorageClasses
  • 3. Persistent Volume Claims
  • 4. Volume Snapshots
• Output Schema
• Edge Cases
• Recommendations Based on Findings

---

Prerequisites

• Cluster name required: Yes
• MCP tools used: describe_eks_resource, list_k8s_resources
• CLI fallback: aws eks, kubectl

---

Detection Strategy

Storage detection covers the full stack from drivers to volumes:

1. CSI Drivers       -> What storage backends are available
2. StorageClasses    -> How storage is provisioned
3. PVCs              -> What storage is currently used
4. Snapshots         -> Backup capability

---

Detection Commands

1. CSI Drivers

Detect which CSI drivers are installed. EKS commonly uses EBS, EFS, and S3 Mountpoint drivers.

EKS-Managed CSI Add-ons:

MCP:

describe_eks_resource(
  resource_type="addon",
  cluster_name="<cluster-name>",
  resource_name="aws-ebs-csi-driver"
)

CLI:

# Check EBS CSI driver (EKS add-on)
aws eks describe-addon --cluster-name <cluster-name> --addon-name aws-ebs-csi-driver \
  --query 'addon.{name:addonName,version:addonVersion,status:status}' 2>/dev/null

# Check EFS CSI driver (EKS add-on)
aws eks describe-addon --cluster-name <cluster-name> --addon-name aws-efs-csi-driver \
  --query 'addon.{name:addonName,version:addonVersion,status:status}' 2>/dev/null

# Check S3 Mountpoint CSI driver (EKS add-on)
aws eks describe-addon --cluster-name <cluster-name> --addon-name aws-mountpoint-s3-csi-driver \
  --query 'addon.{name:addonName,version:addonVersion,status:status}' 2>/dev/null

Example output (EBS CSI detected):

{
  "name": "aws-ebs-csi-driver",
  "version": "v1.28.0-eksbuild.1",
  "status": "ACTIVE"
}

All CSI Drivers (including self-managed):

# List all CSI drivers in cluster
kubectl get csidrivers -o json | jq '.items[] | {name: .metadata.name, attachRequired: .spec.attachRequired}'

Example output:

{"name": "ebs.csi.aws.com", "attachRequired": true}
{"name": "efs.csi.aws.com", "attachRequired": false}
{"name": "s3.csi.aws.com", "attachRequired": false}

Check if EKS Auto Mode manages storage:

# Auto Mode includes EBS CSI automatically
aws eks describe-cluster --name <cluster-name> \
  --query 'cluster.storageConfig.blockStorage.enabled'

2. StorageClasses

Enumerate StorageClasses to understand provisioning options.

CLI:

# List all StorageClasses
kubectl get storageclasses -o json | jq '.items[] | {
  name: .metadata.name,
  provisioner: .provisioner,
  default: (.metadata.annotations["storageclass.kubernetes.io/is-default-class"] == "true"),
  volumeBindingMode: .volumeBindingMode,
  reclaimPolicy: .reclaimPolicy,
  parameters: .parameters
}'

Example output:

{
  "name": "gp3",
  "provisioner": "ebs.csi.aws.com",
  "default": true,
  "volumeBindingMode": "WaitForFirstConsumer",
  "reclaimPolicy": "Delete",
  "parameters": {"type": "gp3", "encrypted": "true"}
}
{
  "name": "efs-sc",
  "provisioner": "efs.csi.aws.com",
  "default": false,
  "volumeBindingMode": "Immediate",
  "reclaimPolicy": "Delete",
  "parameters": {"provisioningMode": "efs-ap"}
}

Count and identify default:

# Count StorageClasses
kubectl get storageclasses --no-headers | wc -l

# Find default StorageClass
kubectl get storageclasses -o json | jq -r '.items[] | select(.metadata.annotations["storageclass.kubernetes.io/is-default-class"] == "true") | .metadata.name'

3. Persistent Volume Claims

Inventory PVCs to understand actual storage usage.

CLI:

# PVC summary by storage class
kubectl get pvc -A -o json | jq '[
  .items | 
  group_by(.spec.storageClassName) | 
  .[] | 
  {
    storageClass: .[0].spec.storageClassName,
    count: length,
    totalRequested: ([.[].spec.resources.requests.storage] | join(", ")),
    statuses: (group_by(.status.phase) | map({status: .[0].status.phase, count: length}))
  }
]'

Example output:

[
  {
    "storageClass": "gp3",
    "count": 5,
    "totalRequested": "10Gi, 20Gi, 50Gi, 10Gi, 100Gi",
    "statuses": [{"status": "Bound", "count": 5}]
  },
  {
    "storageClass": "efs-sc",
    "count": 2,
    "totalRequested": "5Gi, 5Gi",
    "statuses": [{"status": "Bound", "count": 2}]
  }
]

Detailed PVC list:

# List all PVCs with details
kubectl get pvc -A -o json | jq '.items[] | {
  namespace: .metadata.namespace,
  name: .metadata.name,
  storageClass: .spec.storageClassName,
  capacity: .status.capacity.storage,
  status: .status.phase,
  accessModes: .spec.accessModes
}'

Find pending PVCs (potential issues):

kubectl get pvc -A --field-selector status.phase=Pending -o json | jq '.items[] | {
  namespace: .metadata.namespace,
  name: .metadata.name,
  storageClass: .spec.storageClassName
}'

4. Volume Snapshots

Check snapshot capability for backup/restore.

Snapshot Controller:

# Check if snapshot controller is installed
kubectl get deploy -n kube-system snapshot-controller 2>/dev/null

# Or check EKS add-on
aws eks describe-addon --cluster-name <cluster-name> --addon-name snapshot-controller \
  --query 'addon.{name:addonName,version:addonVersion,status:status}' 2>/dev/null

VolumeSnapshotClasses:

# List snapshot classes
kubectl get volumesnapshotclasses -o json 2>/dev/null | jq '.items[] | {
  name: .metadata.name,
  driver: .driver,
  deletionPolicy: .deletionPolicy
}'

Existing snapshots:

# Count snapshots
kubectl get volumesnapshots -A --no-headers 2>/dev/null | wc -l

# List snapshots with details
kubectl get volumesnapshots -A -o json 2>/dev/null | jq '.items[] | {
  namespace: .metadata.namespace,
  name: .metadata.name,
  sourcePVC: .spec.source.persistentVolumeClaimName,
  readyToUse: .status.readyToUse,
  restoreSize: .status.restoreSize
}'

---

Output Schema

storage:
  csi_drivers:
    ebs:
      detected: bool
      version: string
      managed_by: string  # eks-addon | self-managed | auto-mode
    efs:
      detected: bool
      version: string
      managed_by: string
    s3:
      detected: bool
      version: string
    other: list  # Other CSI drivers found
      
  storage_classes:
    count: int
    default: string  # Name of default StorageClass
    list:
      - name: string
        provisioner: string
        volume_binding_mode: string
        reclaim_policy: string
        encrypted: bool
        
  pvcs:
    total: int
    by_storage_class:
      - class: string
        count: int
        total_capacity: string
    by_status:
      bound: int
      pending: int
      lost: int
      
  snapshots:
    controller_installed: bool
    snapshot_classes: int
    volume_snapshots: int

---

Edge Cases

Auto Mode Storage

EKS Auto Mode includes EBS CSI automatically:

• Check cluster.storageConfig.blockStorage.enabled
• Don't flag missing EBS CSI add-on if Auto Mode is enabled

No Default StorageClass

If no default StorageClass exists:

• PVCs without explicit storageClassName will fail
• Recommend setting a default

Pending PVCs

Investigate pending PVCs:

• Missing StorageClass
• Insufficient capacity
• Zone mismatch (EBS is AZ-specific)

EFS vs EBS Choice

Use Case	Recommended
Single-pod access	EBS (gp3)
Multi-pod access	EFS
High IOPS	EBS (io2)
Shared config/data	EFS

---

Recommendations Based on Findings

Finding	Recommendation
No EBS CSI driver	Install aws-ebs-csi-driver add-on (or enable Auto Mode)
No default StorageClass	Set a default to simplify PVC creation
Pending PVCs	Investigate - likely zone or capacity issue
No snapshot controller	Install for backup capability
gp2 StorageClass in use	Migrate to gp3 for better performance/cost
Unencrypted StorageClass	Enable encryption for compliance