Dynamic PVC In Deployment

The current workflow uses the example manifests under curvine-csi/examples in the Curvine source tree:

• storage-class.yaml
• pvc-curvine.yaml
• deployment-curvine.yaml

This path is for stateless workloads that want multiple replicas to share one Curvine-backed PVC.

Example Topology

• StorageClass: curvine-sc
• PVC: curvine-shared-pvc
• Namespace: curvine-system
• Deployment: curvine-test-deployment
• Replicas: 3
• Mount path inside the container: /usr/share/nginx/html

StorageClass Parameters

examples/storage-class.yaml defines the parameters that matter for dynamic provisioning:

Parameter	In example	Meaning
master-addrs	m0:8995,m1:8995,m2:8995	Required Curvine master endpoints
fs-path	/test-data	Path prefix used when the controller creates dynamic volume directories
path-type	DirectoryOrCreate	Create missing parent directories, or require them to exist with Directory
io-threads, worker-threads	commented out	Optional FUSE tuning overrides

Implementation note: the controller code defaults fs-path to / if it is omitted, but the official example sets it explicitly and that is the safer pattern to document and operate.

Apply The Example

cd /path/to/curvine/curvine-csi/examples

kubectl apply -f storage-class.yaml
kubectl apply -f pvc-curvine.yaml
kubectl apply -f deployment-curvine.yaml

What The Example Creates

Shared PVC

pvc-curvine.yaml creates:

• PersistentVolumeClaim/curvine-shared-pvc
• namespace curvine-system
• access mode ReadWriteMany
• requested capacity 5Gi
• storageClassName: curvine-sc

Deployment

deployment-curvine.yaml creates:

• Deployment/curvine-test-deployment
• namespace curvine-system
• 3 nginx replicas
• shared volume mounted at /usr/share/nginx/html

Each replica writes the pod hostname and timestamp into the same shared Curvine-backed directory.

Verify Shared Access

kubectl get pvc -n curvine-system curvine-shared-pvc
kubectl get pods -n curvine-system -l app=curvine-test -o wide
kubectl get pv

Write from one pod and read from another:

POD1=$(kubectl get pod -n curvine-system -l app=curvine-test -o jsonpath='{.items[0].metadata.name}')
POD2=$(kubectl get pod -n curvine-system -l app=curvine-test -o jsonpath='{.items[1].metadata.name}')

kubectl exec -n curvine-system "$POD1" -- sh -c 'echo "hello from pod1" > /usr/share/nginx/html/shared.txt'
kubectl exec -n curvine-system "$POD2" -- cat /usr/share/nginx/html/shared.txt

If the second command prints the same content, the deployment is reading and writing through the same Curvine PVC as intended.

How Dynamic Paths Are Built

For dynamic provisioning, the controller generates:

• volumeHandle = {cluster-id}@{fs-path}@{pv-name}
• curvine-path = {fs-path}/{pv-name}

The node plugin then reuses or creates a FUSE mount based on master-addrs + fs-path, and bind-mounts the generated curvine-path into the pod. The exact lifecycle is described in Framework.