ArgoCD Application Pull Controller
The ArgoCD application controller uses the hub-spoke pattern or pull model mechanism for decentralized resource delivery to remote clusters. By using Open Cluster Management (OCM) APIs and components, the ArgoCD Applications will be pulled from the multi-cluster control plane hub cluster down to the registered OCM managed clusters. To try it out, check out the Getting Started Guide.
Overview
The current ArgoCD resource delivery is primarily pushing resources from a centralized cluster to the remote/managed clusters.
By using this controller, users can have a pull model resource delivery mechanism.
The pull model may offers some advantages over the existing push model:
- Scalability: hub-spoke pattern may offers better scalability.
- Security: cluster credentials doesn't have to be stored in a centralized environment may enhance security.
- It may reduce the impact of a single point of centralized failure.
This ArgoCD pull model controller on the Hub cluster will create ManifestWork objects wrapping Application objects as payload. The OCM agent on the Managed cluster will see the ManifestWork on the Hub cluster and pull the Application down.