Key Concepts
See also: Concepts and Personas for detailed persona definitions (Service Provider, Consumer, Instance Admin) and Controller Architecture for detailed controller diagrams and resource dependency graphs.
graph TD
subgraph "Management Cluster"
HC[HostedCluster
namespace: clusters] NP[NodePool
namespace: clusters] subgraph "CP Namespace: clusters-my-cluster" HCP[HostedControlPlane] CPO[Control Plane Operator] ETCD[etcd] KAS[kube-apiserver] KCM[kube-controller-manager] SCHED[kube-scheduler] OAPI[openshift-apiserver] PKI[PKI Operator] IGN[Ignition Server] end HO[HyperShift Operator
namespace: hypershift] end subgraph "Guest Cluster - Data Plane" W1[Worker Node 1] W2[Worker Node 2] W3[Worker Node N] end HO -->|manages| HC HO -->|manages| NP HO -->|creates| HCP HO -->|deploys| CPO CPO -->|manages| ETCD CPO -->|manages| KAS CPO -->|manages| KCM CPO -->|manages| SCHED CPO -->|manages| OAPI CPO -->|manages| PKI CPO -->|manages| IGN KAS -.->|konnectivity tunnel| W1 KAS -.->|konnectivity tunnel| W2 KAS -.->|konnectivity tunnel| W3 IGN -.->|ignition configs| W1 IGN -.->|ignition configs| W2 IGN -.->|ignition configs| W3
namespace: clusters] NP[NodePool
namespace: clusters] subgraph "CP Namespace: clusters-my-cluster" HCP[HostedControlPlane] CPO[Control Plane Operator] ETCD[etcd] KAS[kube-apiserver] KCM[kube-controller-manager] SCHED[kube-scheduler] OAPI[openshift-apiserver] PKI[PKI Operator] IGN[Ignition Server] end HO[HyperShift Operator
namespace: hypershift] end subgraph "Guest Cluster - Data Plane" W1[Worker Node 1] W2[Worker Node 2] W3[Worker Node N] end HO -->|manages| HC HO -->|manages| NP HO -->|creates| HCP HO -->|deploys| CPO CPO -->|manages| ETCD CPO -->|manages| KAS CPO -->|manages| KCM CPO -->|manages| SCHED CPO -->|manages| OAPI CPO -->|manages| PKI CPO -->|manages| IGN KAS -.->|konnectivity tunnel| W1 KAS -.->|konnectivity tunnel| W2 KAS -.->|konnectivity tunnel| W3 IGN -.->|ignition configs| W1 IGN -.->|ignition configs| W2 IGN -.->|ignition configs| W3
Glossary
For full persona and concept definitions, see Concepts and Personas.
| Term | Description | Start Reading Here |
|---|---|---|
| Management Cluster | The OpenShift/K8s cluster where HyperShift operators run and where control plane pods live | hypershift-operator/main.go |
| Guest Cluster (Hosted Cluster) | The cluster end users consume. Only has worker nodes | - |
| HostedCluster (HC) | User-facing CRD declaring the intent to create a cluster. Lives in the user's namespace | api/hypershift/v1beta1/hostedcluster_types.go |
| HostedControlPlane (HCP) | Internal CRD created by the HC controller. Lives in the control plane namespace. The CPO reads it to know what to deploy | api/hypershift/v1beta1/hosted_controlplane.go |
| NodePool (NP) | User-facing CRD defining a scalable set of worker nodes. References a HostedCluster | api/hypershift/v1beta1/nodepool_types.go |
| Control Plane Namespace | Namespace ({hc-ns}-{hc-name}) where all control plane components live |
hypershift-operator/controllers/manifests/manifests.go |
| HyperShift Operator (HO) | Main operator managing HostedClusters and NodePools | hypershift-operator/controllers/hostedcluster/hostedcluster_controller.go |
| Control Plane Operator (CPO) | Runs inside each CP namespace and manages all control plane components | control-plane-operator/controllers/hostedcontrolplane/hostedcontrolplane_controller.go |
| PKI Operator | Certificate operator handling rotation and signing | control-plane-pki-operator/operator.go |
| Ignition Server | HTTPS server that serves ignition configs to worker nodes during bootstrap | ignition-server/cmd/start.go |