Adopting a Standardized PlacementDecision API from SIG Multi-Cluster

[mikeshng]

Describe the enhancement

OCM currently defines and produces its own PlacementDecision API. In parallel, SIG Multicluster (SIG MC) has defined a standardized PlacementDecision API intended to be consumed consistently across the Kubernetes multicluster ecosystem. To improve interoperability and align with SIG MC guidance, OCM should adopt and generate the SIG MC PlacementDecision API in addition to (or as part of) its existing placement mechanism.

By producing the SIG MC PlacementDecision API, OCM would enable third party consumers, such as Argo CD to directly import and rely on a standardized API, rather than requiring OCM (or other providers) specific integrations.

Adopting the SIG MC PlacementDecision API will:

• Align OCM with upstream SIG Multi-Cluster guidance and standardization efforts.
• Improve ecosystem interoperability and reduce custom integration.
• Enable third-party consumers to work uniformly across multiple multi-cluster implementations.
• Position OCM as a compliant producer of standardized multicluster placement decisions.

So the main goal is to ensure OCM generates the SIG MC PlacementDecision API so that consumers can rely on a common, standardized interface across multicluster providers.

Refs:

• https://github.com/kubernetes/enhancements/blob/master/keps/sig-multicluster/5313-placement-decision-api/README.md
• https://github.com/kubernetes-sigs/cluster-inventory-api?tab=readme-ov-file#placementdecision-api