KEP-1488: In-tree Storage Plugin to CSI Migration - GCE PD

Implementation History
STABLE Implementable
Created 2021-12-17
Updated 2022-01-05
Latest v1.25
Milestones
Alpha v1.14
Beta v1.17
Stable v1.25
Related Enhancements
Ownership
Owning SIG
SIG Storage
Participating SIGs
SIG Cluster Lifecycle
Primary Authors
@davidz627

In-tree Storage Plugin to CSI Migration - GCE 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

  • CSIMigrationGCE
    • 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/gce-pd will be redirect to use the corresponding CSI driver. From a user perspective, nothing will be noticed.
  • InTreePluginGCEUnregister
    • 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/gce-pd as one of the in-tree storage plugin provisioners. This flag standalone can work out of CSI Migration features.
    • However, when all InTreePluginGCEUnregister, CSIMigrationGCE and CSIMigration feature flags are enabled at the same time. The kube-controller-manager will skip the feature flag checking on kubelet and treat GCE PD CSI migration as already complete. And directly redirect traffic to CSI driver for all gce pd related operations.

Production Readiness Review Questionnaire

Please refer to the CSI Migration Production Readiness Review Questionnaire .

Design Details

Test Plan

[X] I/we understand the owners of the involved components may require updates to existing tests to make this code solid enough prior to committing the changes necessary to implement this enhancement.

Prerequisite testing updates

No additional tests are needed, rather the issue is orchestrating CSI driver deployment for prow jobs. This has been complicated by the cloud provider extraction work, which no longer permits cloud provider specific orchestration in the k/k repository. This means that it is not possible to run any test for gce-pd in k/k. All such tests have been moved to the cloud-provider-gcp repo and test infrastructure .

Unit tests
  • k8s.io/csi-translation-lib/plugins/gce_pd.go: 2022-06-21 - 69.7
Integration tests

N/A

e2e tests

Implementation History

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

  • 2021-09-08 KEP created

Major milestones for GCE PD in-tree plugin CSI migration:

  • 1.14

    • GCE PD CSI migration to Alpha

  • 1.17

    • GCE PD CSI migration to Beta, off by default.

  • 1.23

    • GCE PD CSI migration to Beta, on by default.

  • 1.25

    • GCE PD CSI migration to GA