Feature Overview (aka. Goal Summary)

GCP Filestore multishares for GKE allocates up to 80 shares across a single enterprise-tier instance.

This capability optimizes share usage within the Filestore instances and provides the following benefits:

• Gives users the control to estimate and set maximum share capacity
• Optimizes the number of shares per instance
• Optimizes the use of Filestore instances in their associated GKE storage pools
• Improves cost

Goals (aka. expected user outcomes)

The goal of this feature is to support the Filstore CSI "multishare" option that allows to consume a enterprise filestore instance.

https://cloud.google.com/filestore/docs/multishares

This requires an enterprise tier instance on the GCP side and a specific SC parameter. The CSI driver has to be started with a specific option to enable the multishare feature.

Requirements (aka. Acceptance Criteria):

Make sure we do whatever is needed to enabled this feature at the driver level.

Run the usual CI with the "multishare" option on in the SC. Identify any gaps or regression. If any decide if this is productisable as is it or just document them.

Document how to enabled the feature at the storage class level.

Use Cases (Optional):

1. As an admin I would like to leverage GCP filestore mutishare instance in order to leverage the cost benefit and optimise the use of filestore instances. 

Questions to Answer (Optional):

Include a list of refinement / architectural questions that may need to be answered before coding can begin. Initial completion during Refinement status.

Out of Scope

High-level list of items that are out of scope. Initial completion during Refinement status.

Background

We introduced GCP Filestore CSI GA in 4.14 but we are missing some optional features. This driver's feature was requested via RFE.

Customer Considerations

Provide any additional customer-specific considerations that must be made when designing and delivering the Feature. Initial completion during Refinement status.

Documentation Considerations

Document how an admin could use/expose this feature as well as limitations if any. Perhaps document the GCP requirements or link to external dosc.