Feature Overview

• Today, most of RHACM utilizes a pattern of operating on Kubernetes Custom Resources and therefore the cluster's etcd is leveraged to store data. In order to achieve high-scale Kubernetes cluster management requirements, we need to introduce a traditional relational database above all RHACM hub clusters that stores relevant data including the cluster inventory, configuration policies, etc.
• Once the database is deployed and accessible via a REST API, we can create an agent that is deployed on a RHACM hub to connect to that REST API / database for sharing cluster inventory and synchronizing other resources.

Slack: #forum-acm-nextgen-controlplane

Goals

• Develop a template and process for representing Kubernetes resources in a relational database
• Investigate requirements for operating and maintaining the database in the context of RH-managed versus customer-managed
  • RH-managed:
    • Leverage an existing service such as Amazon Relational Database Service (RDS) 
  • Customer-managed includes considerations for:
    • Data Recovery
    • Availability
    • Management and Maintenance
    • Problem Determination
    • Fixes / CVE maintenance
• Develop an agent that can synchronize information between the database and RHACM hub clusters.

Use Cases

• xCM
  • Cluster inventory data can be stored centrally in this database and isolated based on data sovereignty requirements.
  • Provide a standardized schema for representing clusters in a database across multiple stakeholder services including xCM, AMS, Cluster Service, OSD Fleet Manager, Kafka Fleet Manager, and ACS Fleet Manager.
  • Host the cluster inventory data that will be read by the xCM connector to share inventory information between OCM and ACM.
• Additional layered services on top of xCM including a Configuration Management Service implementation.

Previous Work

• AMS - Access Management Service database, this is what you see on console.redhat.com when you look at your subscribed clusters (AWS RDS).
• Cluster Service Database (AWS RDS).
• OSD Fleet Manager, ACS Fleet Manager, Kafka Fleet Manager (AWS RDS), all use diverged schemas.
• There was work that was shelved to use CockroachDB instead of etcd to back a Kubernetes API server in KCP.

Reference material

• Kubernetes Resource Database
• xCM Relational Database
• Next Gen Control Plane Miro Board