k8s-volume-utils

k8s-volume-utils

A simple tool to reuse PV. It can rename a PVC or move a PVC from one namespace to another namespace. After that we can resue bound PV without data lost

Usage:

k8s-volume-utils pvc
   It is used to rename a PVC object in kubernetes cluster.
   It will delete original PVC and create new PVC referring to same PV.
   New PVC can be in another namespace.
k8s-volume-utils pv
   It can help to reuse a pv

Usage:
  k8s-volume-utils [command]

Available Commands:
  help        Help about any command
  pv          help to reuse a pv
  pvc         rename PVC object in kubernetes clusterd

Example

1. create two namespaces for test
   oc new-project pvc
oc new-project pvc1
oc project pvc
2. create a statefulset and it will create a PV.
   • Edit sts-pvc-test.yaml to update its storageClassName to available one on your cluster.
   • oc create -f sts-pvc-test.yaml
   • oc get po www-pvc-test-0 -w to wait pod running. Then

     $ oc exec pvc-test-0 cat /usr/share/nginx/html/a.txt
      a
     

     We can see there is data in PV.
3. delete the statefulset by oc delete -f sts-pvc-test.yaml. Now we have a pvc www-pvc-test-0 to be reused by other service.
4. move pvc to namespace pvc1 by go run main.go pvc www-pvc-test-0 "" pvc1
oc get pvc -n pvc1 to check PVC www-pvc-test-0 is moved to namespace pvc1.
5. create another statefulset to reuse the same PV.
   • Edit sts-pvc-test.yaml
     Change "echo a > /usr/share/nginx/html/a.txt;sleep 3600" to "echo b > /usr/share/nginx/html/b.txt;sleep 3600"
   • oc -n pvc1 create -f sts-pvc-test.yaml
   • when pod pvc-test-0 is running in namespace pvc1. Run oc exec pvc-test-0 cat /usr/share/nginx/html/a.txt -n pvc1 to check data is not lost.