Retain Persistence Volume and use the PV for new Helm install

It's still not resolved issue by Helm.

• https://github.com/helm/charts/issues/1472
• https://github.com/helm/helm/issues/1933

The 'hack' to deal with it, you can find here:

https://groups.google.com/forum/#!topic/kubernetes-sig-apps/sLL2pCJ5Ab8

I found one work around.I have created a PVC independent of helm chart and just using it in my deployment.yaml file.
If there is existing claim just use the existing one otherwise create a new Claim.

 {{- if .Values.persistence.enabled }}      {{- if .Values.persistence.existingClaim }}        persistentVolumeClaim:          claimName: {{ .Values.persistence.existingClaim }}      {{- else}}        persistentVolumeClaim:          claimName: {{ (include "mongodb.fullname" .) }}      {{- end}}  

The existing PV will not be able to be bound to the new PVC. However, the disk that your PV (pvc-fc29a491-499a-11e9-a426-42010a800ff9) references can be bound to your PVC. The configuration of your new PV will depend slightly on what cloud provider/bare metal host you are using. I followed this to come to the example shown below. This example shows how to do it with a Google Cloud GCE persistent disk. The order matters here; make sure you create the PV (that references your existing persistent disk) before creating your PVC.

---apiVersion: v1kind: PersistentVolumemetadata:  name: myPVspec:  capacity:    storage: 8Gi  accessModes:    - ReadWriteOnce  gcePersistentDisk:    pdName: myPdDiskName    fsType: ext4  storageClassName: standard  claimRef:    name: myPvcName    namespace: myNameSpace---apiVersion: v1kind: PersistentVolumeClaimmetadata:  name: myPvcName  namespace: myNameSpacespec:  accessModes:    - ReadWriteOnce  resources:    requests:      storage: 8Gi