Allow customisation of the maximum number of snapshots in vSphere CSI

Epic Goal*

The goal of this epic is to allow admins to configure the maximum number of snapshots per volume in vSphere CSI and find an way how to add such extension to OCP API.

Possible future candidates:

• configure EFS volume size monitioring (via driver cmdline arg.) - STOR-1422
• configure OpenStack topology - RFE-11

 
Why is this important? (mandatory)

Currently the maximum number of snapshots per volume in vSphere CSI is set to 3 and cannot be configured. Customers find this default limit too low and are asking us to make this setting configurable.

Maximum number of snapshot is 32 per volume

https://kb.vmware.com/s/article/1025279

https://docs.vmware.com/en/VMware-vSphere-Container-Storage-Plug-in/3.0/vmware-vsphere-csp-getting-started/GUID-E0B41C69-7EEB-450F-A73D-5FD2FF39E891.html#GUID-7BA0CDAE-E031-470E-A685-60C82DAE36D2__GUID-D9A97A90-2777-46EA-94EB-F04A27FBB76D

 
Scenarios (mandatory) 

Provide details for user scenarios including actions to be performed, platform specifications, and user personas.  

1. As an admin I would like to configure the maximum number of snapshots per volume.
2. As a user I would like to create more than 3 snapshots per volume

 
Dependencies (internal and external) (mandatory)

1) Write OpenShift enhancement (STOR-1759)

2) Extend ClusterCSIDriver API (TechPreview) (STOR-1803)

3) Update vSphere operator to use the new snapshot options (STOR-1804)

4) Promote feature from Tech Preview to Accessible-by-default (STOR-1839)

• prerequisite: add e2e test and demonstrate stability in CI (STOR-1838)

Contributing Teams(and contacts) (mandatory) 

Our expectation is that teams would modify the list below to fit the epic. Some epics may not need all the default groups but what is included here should accurately reflect who will be involved in delivering the epic.

• Development - STOR
• Documentation - STOR
• QE - STOR
• PX - Enablement
• Others -

Acceptance Criteria (optional)

Configure the maximum number of snapshot to a higher value. Check the config has been updated and verify that the maximum number of snapshots per volume maps to the new setting value.

Drawbacks or Risk (optional)

Setting this config setting with a high value can introduce performances issues. This needs to be documented.

https://kb.vmware.com/s/article/1025279

Done - Checklist (mandatory)

The following points apply to all epics and are what the OpenShift team believes are the minimum set of criteria that epics should meet for us to consider them potentially shippable. We request that epic owners modify this list to reflect the work to be completed in order to produce something that is potentially shippable.

• CI Testing -  Basic e2e automationTests are merged and completing successfully
• Documentation - Content development is complete.
• QE - Test scenarios are written and executed successfully.
• Technical Enablement - Slides are complete (if requested by PLM)
• Engineering Stories Merged
• All associated work items with the Epic are closed
• Epic status should be “Release Pending”