Introduce new CRD as StorageNode for better usability

[mlycore]

Apache ShardingSphere

Apache ShardingSphere is positioned as a Database Plus, and aims at building a standard layer and ecosystem above heterogeneous databases. It focuses on how to reuse existing databases and their respective upper layer, rather than creating a new database. The goal is to minimize or eliminate the challenges caused by underlying databases fragmentation.

Page: https://shardingsphere.apache.org/
Github: https://github.com/apache/shardingsphere 

Background

There is a proposal about new CRD Cluster and ComputeNode as belows:

• WIP: [New Feature] Introduce new CRD Cluster #167
• [Feat] Introduce new CRD as ComputeNode for better usability #166

Currently we try to promote StorageNode as major CRD to represent a set of storage units for ShardingSphere.

Task

The elementary task is that the storage node controller could manage the lifecycle of a set of storage units, like PostgreSQL, in kubernetes.

We don't hope to create another wheel like pg-operator. So consider using a predefined parameter group to generate the target CRD.

• Create a PostgreSQL cluster while a StorageNode with pg parameters is created
• Update the PostgreSQL cluster while updated StorageNode
• Delete the PostgreSQL cluster while deleted StorageNode. Notice this may need a deletion strategy.
• Reconciling StorageNode according to the status of PostgreSQL cluster.
• The status of StorageNode would be consumed by common storage units related DistSQLs

Relevant Skills

1. Master Go language, Ginkgo test framework
2. Have a basic understanding of Apache ShardingSphere Concepts
3. Be familiar with Kubernetes Operator, kubebuilder framework

Targets files

StorageNode Controller - https://github.com/apache/shardingsphere-on-cloud/blob/main/shardingsphere-operator/pkg/controllers/storagenode_controller.go

[yikuaibro]

I am very interested in this project and submit my proposal.

[mlycore]

I am very interested in this project and submit my proposal.

Yes thanks !

[mlycore]

@Xu-Wentao has proposed a pr #292