KEP-1490: In-tree Storage Plugin to CSI Migration - Azuredisk

Implementation History
STABLE Implemented
Created 2022-01-05
Updated 2022-01-05
Latest v1.24
Milestones
Alpha v1.15
Beta v1.19
Stable v1.24
Related Enhancements
Ownership
Owning SIG
SIG Storage
Participating SIGs
SIG Cluster Lifecycle
Primary Authors
@andyzhangx

In-tree Storage Plugin to CSI Migration - AzureDisk Design Doc

Table of Contents

Summary

This document present as a vendor specific KEP for the parent KEP CSI Migration

This inherits all the contents from its parent KEP. It will introduce two new feature gates to be used as as described in its parent KEP. For all other contents, please refer to the parent KEP.

New Feature Gates

  • CSIMigrationAzureDisk
    • As describe in CSI Migration , when this feature flag && the CSIMigration is enabled at the same time, all operations related to the in-tree volume plugin kubernetes.io/azure-disk will be redirect to use the corresponding CSI driver. From a user perspective, nothing will be noticed.
  • InTreePluginAzureDiskUnregister
    • This flag technically is not part of CSI Migration design. But it happens to be related and helps with CSI Migration. The name speaks for itself, when this flag is enabled, kubernetes will not register the kubernetes.io/azue-disk as one of the in-tree storage plugin provisioners. This flag standalone can work out of CSI Migration features.
    • However, when all InTreePluginAzureDiskUnregister, CSIMigrationAzureDisk and CSIMigration feature flags are enabled at the same time. The kube-controller-manager will skip the feature flag checking on kubelet and treat Azure Disk CSI migration as already complete. And directly redirect traffic to CSI driver for all azure disk related operations.

Production Readiness Review Questionnaire

Please refer to the CSI Migration Production Readiness Review Questionnaire .

Implementation History

Major milestones in the life cycle of a KEP should be tracked in Implementation History.

  • 2022-01-05 KEP created

Major milestones for Azure Disk in-tree plugin CSI migration:

  • 1.15

    • AzureDisk CSI migration to Alpha

  • 1.19

    • AzureDisk CSI migration to Beta, off by default.

  • 1.23

    • AzureDisk CSI migration to Beta, on by default.

  • 1.24

    • AzureDisk CSI migration to GA