Missed case for listing cStor volumes

[vaniisgh]

When a PVC is provisioned and the CStorVolume might not be created the current logic is not sufficient to list the instances.

[kmova]

This can be expanded into a few more test cases like:

• Checking what is the minimum OpenEBS version required for openebsctl to work. And in case user tries with older openebs version, does it gracefully error out?
• Test the commands by breaking the components - for example if listing cstor volume:
  • create a PV (with reclaim policy as retain), delete the PVC
  • create a PV - delete manually some of the sub CRs and check if openebsctl can gracefully validate and display missing information

[Abhinandan-Purkait]

We have tried the above mentioned cases and these are the observations:

• If CstorVolume is not created, the get command will not the list the volume.
• If PVC is deleted and the volume has a reclaim policy of Retain, then the flow works as expected, the CstorVolume is listed and the describe also works without any error.
• If subCR like CVC is deleted then theCstorVolume and the CVR also gets deleted and thus it is will not list the CstorVolume. Although if we do a kubectl get pv we will be able to see the PV and if we pass the PV name in the kubectl openebs volume describe command it will show a error i.e. failed to execute volume info command, getting cStor volumes: error while while getting volume <volume name>: cstorvolumes.cstor.openebs.io "<volume name>" not found.
• If subCR like CVR is deleted then the flow works as expected i.e the CstorVolume will be listed and on describe in the replica section it shows None of the replicas are running