KB Postgres + MoveToKube Postgres Operator

[IngwiePhoenix]

Hello there!

I would like to use the database and user/password CRDs that MoveToKube's Postgres Operator provides against a Kubeblocks based Postgres cluster. But while reading th edocs, there were a few things I didn't quite understand:

• In a Clusters componentDef, I have to fill in the template - which in my case should be postgres. But, what about clusterVersionRef: postgresql-14.8.0? Where can I see a list of all available versions?
• In componentSpecs, each componentDefRef points to one of the containers in the underlying definition, yes?

Other than that, I think I understood everything else.

Thank you and kind regards!

[michelle-0808]

[Y-Rookie]

@IngwiePhoenix Hello, may I ask which version of KubeBlocks you are using?

Before answering your question, let me provide some background. In earlier versions of KubeBlocks (prior to v0.8), we defined a cluster using cluster + ClusterDefinition + clusterVersion. In this setup, ClusterDefinition defines multiple components, and clusterVersion is used to define multiple versions. In the Cluster API, clusterVersionRef references a specific version of clusterVersion, while cluster.spec.componentSpecs[*].componentDefRef references a specific component defined in ClusterDefinition.

After v0.8 and v0.9, we separated the definitions of multiple components from ClusterDefinition. Each individual component was redefined as ComponentDefinition, and each component's version was defined as ComponentVersion. Additionally, a new topologies field was introduced in ClusterDefinition to describe various topologies of the cluster.

Based on the above background and considering version transition and compatibility, we added the componentDef field in cluster.spec.componentSpecs to reference ComponentDefinition.

In summary, there are currently two ways to create a cluster:

• Create a Legacy cluster: using cluster.spec.componentSpecs[*].componentDefRef + ClusterVersion + ClusterDefinition.

• Create a cluster based on the new API: using cluster.spec.componentSpecs[*].componentDef + ComponentDefinition + ComponentVersion + ClusterDefinition (optional, for topology).

The first method will not be supported in v1.0, meaning that cluster.spec.componentSpecs[*].componentDefRef and cluster.spec.clusterVersionRef will be removed.

I hope the information above helps you. If you have any further questions, feel free to ask!