VolumeGroupSnapshot Implementation Story

Based on Velero Issue: #8865

Parent Issue: #8447

Design Document: #8778

Problem Statement

This story implements VolumeGroupSnapshot (VGS) support in Velero to address the need for grouped volume snapshots that maintain data consistency across multiple PVCs.

Solution Overview

Implement VGS support by extending Velero's backup workflow to handle grouped snapshots using the Kubernetes VolumeGroupSnapshot API. Users will be able to group PVCs by specifying a label key, ensuring atomic snapshot operations for data consistency.

Major Implementation Tasks

The implementation involves three major components as outlined in the upstream issue:

1. Accept VGS Label from User

_ _Reference:* #8934

• Implement user interface to specify label keys for PVC grouping
• Validate label selection and grouping logic
• Handle user input for VGS configuration

2. Update Existing PVC ItemBlockAction Plugin

_ _Reference:* #8935

• Modify existing PVC plugins to support VGS workflows
• Ensure compatibility with current ItemBlockAction functionality
• Integrate VGS detection and handling logic

3. Updates to CSI PVC Plugin

_ _Reference:* #8936

• Enhance CSI PVC plugin for VGS object creation
• Implement VGS-specific snapshot operations
• Ensure proper integration with CSI drivers

Technical Requirements

Core Functionality

• Group PVCs using label-based selection
• Create VolumeGroupSnapshot objects during backup
• Ensure atomic snapshot operations across grouped volumes
• Maintain backwards compatibility with existing workflows

Integration Points

• Kubernetes VolumeGroupSnapshot API integration
• CSI driver compatibility requirements
• Plugin architecture enhancements
• RBAC permissions for VGS operations

Success Criteria

Functional Requirements

• Users can specify label keys for PVC grouping
• VGS objects are created successfully during backup
• Grouped snapshots maintain data consistency
• Restore operations work correctly with VGS backups

Non-Functional Requirements

• Backwards compatibility with existing Velero installations
• Performance optimization for grouped snapshot operations
• Proper error handling for incomplete groups
• Comprehensive test coverage

Testing Strategy

• Unit tests for VGS workflow components
• Integration tests with various CSI drivers
• End-to-end testing with real applications
• Performance benchmarking for grouped operations
• Backwards compatibility validation

Target Release

• Velero version: v1.17
• OADP version: 1.6.0

Dependencies

This story is a dependency of the VolumeGroupSnapshot Support Implementation epic and contributes to the overall VGS feature delivery.