Feature Overview:

Ensure CSI Stack for Azure is running on management clusters with hosted control planes, allowing customers to associate a cluster as "Infrastructure only" and move the following parts of the stack:

• Azure Disk CSI driver
• Azure File CSI driver
• Azure File CSI driver operator

Value Statement:

This feature enables customers to run their Azure infrastructure more efficiently and cost-effectively by using hosted control planes and supporting infrastructure without incurring additional charges from Red Hat. Additionally, customers should care most about workloads not the management stack to operate their clusters, this feature gets us closer to this goal.

Goals:

1. Ability for customers to associate a cluster as "Infrastructure only" and pack control planes on role=infra nodes.
2. Ability to run cluster-storage-operator (CSO) + Azure Disk CSI driver operator + Azure Disk CSI driver control-plane Pods in the management cluster.
3. Ability to run the driver DaemonSet in the hosted cluster.

Requirements:

1. The feature must ensure that the CSI Stack for Azure is installed and running on management clusters with hosted control planes.
2. The feature must allow customers to associate a cluster as "Infrastructure only" and pack control planes on role=infra nodes.
3. The feature must enable the Azure Disk CSI driver, Azure File CSI driver, and Azure File CSI driver operator to run on the appropriate clusters.
4. The feature must enable the cluster-storage-operator (CSO) + Azure Disk CSI driver operator + Azure Disk CSI driver control-plane Pods to run in the management cluster.
5. The feature must enable the driver DaemonSet to run in the hosted cluster.
6. The feature must ensure security, reliability, performance, maintainability, scalability, and usability.

Use Cases:

1. A customer wants to run their Azure infrastructure using hosted control planes and supporting infrastructure without incurring additional charges from Red Hat. They use this feature to associate a cluster as "Infrastructure only" and pack control planes on role=infra nodes.
2. A customer wants to use Azure storage without having to see/manage its stack, especially on a managed service. This would mean that we need to run the cluster-storage-operator (CSO) + Azure Disk CSI driver operator + Azure Disk CSI driver control-plane Pods in the management cluster and the driver DaemonSet in the hosted cluster. 

Questions to Answer:

1. What Azure-specific considerations need to be made when designing and delivering this feature?
2. How can we ensure the security, reliability, performance, maintainability, scalability, and usability of this feature?

Out of Scope:

Non-CSI Stack for Azure-related functionalities are out of scope for this feature.

Workload identity authentication is not covered by this feature - see STOR-1748

Background

This feature is designed to enable customers to run their Azure infrastructure more efficiently and cost-effectively by using HyperShift control planes and supporting infrastructure without incurring additional charges from Red Hat.

Documentation Considerations:

Documentation for this feature should provide clear instructions on how to enable the CSI Stack for Azure on management clusters with hosted control planes and associate a cluster as "Infrastructure only." It should also include instructions on how to move the Azure Disk CSI driver, Azure File CSI driver, and Azure File CSI driver operator to the appropriate clusters.

Interoperability Considerations:

This feature impacts the CSI Stack for Azure and any layered products that interact with it. Interoperability test scenarios should be factored by the layered products.