Kubernestes copy existing PVC to another

README.md

How to Copy existing PVC to another namespace

To achieve this goal we have to :

1. Create PVC clone (two methods : k8s clone feature or snapshot + restore)
2. Set reclaim policy for the cloned PV to Retain !
3. Delete PVC clone (and snapshot if necessary)
4. Realease the clone PV (set claimRef to null)
5. Create the new namespace
6. Create a new PVC that meets realesed PV specification (size, matchLabels ...)

Command lines :

# Protect volume for deletion (Tip: create custom StorageClass with this propety as default)
k patch pv pvc-1-clone -p '{"spec": {"persistentVolumeReclaimPolicy": "Retain"}}' --namespace old-ns

# Remove temp volumesnapshot resource
k delete volumesnapshot pvc-1-snap --namespace old-ns

# Remove temp pvc resource : change status to `Released` on the corresponding PV
k delete pvc pvc-1-clone --namespace old-ns

# Make : PV free to be claimed by new PVC : change status to `Available`
k patch pv -p '{"spec": {"claimRef": null}}' --namespace old-ns

k apply -f new-ns-pvc.yaml --namespace new-ns

Exemple PVC resource : new-ns-pvc.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: new-ns-pvc
spec:
  accessModes:
    - ReadWriteOnce
  volumeMode: Filesystem
  resources:
    requests:
      storage: 2Gi
  # selector: # Useful if PV have label (more accurate)
  #   matchLabels:
  #     app: "new-ns-env-app" 

TIPS & TRICKS : Copying kubernetes resources accross namespaces

OLD_NS=my-ns-1
kubectl get rs,secrets -o json --namespace $OLD_NS | jq '.items[].metadata.namespace = "my-ns-2"' | kubectl create-f  -

clone-pvc-by-snapshot.yaml

apiVersion: snapshot.storage.k8s.io/v1alpha1
kind: VolumeSnapshot
metadata:
  name: pvc-1-snap
  labels: 
    app: demo-storage
spec:
  source:
    name: pvc-1
    kind: PersistentVolumeClaim
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-1-clone
  labels: 
    app: demo-storage  
spec:
  dataSource:
    name: pvc-1-snap
    kind: VolumeSnapshot
    apiGroup: snapshot.storage.k8s.io
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi # Equal or greater than pvc-1 size