You determine the different services to use to achieve a fully upstream-compliant Kubernetes cluster in your SDDC.
Red Hat OpenShift Cluster
The Red Hat OpenShift cluster deployed on vSphere consists of one or more virtual machines dedicated to run control plane workloads and one or more virtual machines dedicated to run tenant workloads.
Control plane nodes perform multiple functions:
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Run workloads
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Perform support functions such as user and administrator access
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Authentication
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Image registry
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Monitor the cluster
Worker nodes run tenant workloads instantiated by administators.
As of Red Hat OpenShift 4.3, to instantiate a cluster on vSphere, you must leverage User-Provisioned Infrastructure (UPI). You are responsible for deployment and configuration of the entire cluster.
| Decision ID |
Design Decision |
Design Justification |
Design implication |
|---|---|---|---|
| SDDC-RHOSWLD-VI-OCP-001 |
Deploy the Red Hat OpenShift cluster to the shared edge and workload cluster in the workload domain. |
Deployment of both control plane and worker nodes to the shared edge and workload cluster allows for efficient use of hardware resources. If the resources provided by the shared edge and worklod cluster are exhausted, additional vSphere clusters can be instantiated within the workload domain. |
You must size the shared edge and workload cluster to support the control plane nodes, worker nodes, any additional management functions, NSX-T Edge virtual machines, and tenant workloads that run within the Red Hat OpenShift cluster. |
| SDDC-RHOSWLD-VI-OCP-002 |
Use Red Hat Enterprise Linux CoreOS (RHCOS) for both control plane and worker nodes in the cluster. |
Use of RHCOS is required for control plane nodes in Red Hat OpenShift 4. Use of RHCOS for worker nodes provides a consistent deployment and management experience across both worker and control plane nodes in the cluster. |
You must use Ignition to deploy and configure both control plane and worker nodes in the cluster. |
