Intro

See a blog post about this solution here.

Prerequisites

• OpenShift GitOps Operator v1.8+
• MetalLB Operator
• ACM 2.7+ or MCE 2.2+
• Enable the Hosted Control Plane feature: RHACM Docs - Enable Hypershift Add-On
• Enable CIM: RHACM Docs - Enable CIM

I have written an Ansible Playbook that can set up the management cluster as required, see here.

DNS for the Hosted Cluster

You need to create DNS entries for api.<hosted-cluster-name>.<domain> and *.apps.<hosted-cluster-name>.<domain>, just like you would for a standalone cluster.

API

This Helm chart utilizes MetalLB (layer 2) on the management cluster in order to serve the API for the hosted cluster. This means that the IP address you choose for the Hosted Cluster API needs to be in the same subnet as the management cluster.

Ingress

This Helm chart utilizes MetalLB (layer 2) on the hosted cluster for the Ingress. This means that the IP address you choose for the Hosted Cluster Ingress needs to be in the same subnet as the hosted cluster workers.

Configuration

The Values file for the Helm chart is an OpenShift Install Config with an extra hypershift section. See the example. Hosted Control Plane (HyperShift) clusters do not have any control plane nodes, therefore only worker nodes should be specified in the Install Config.

Example

Example ArgoCD application:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: hypershift-cluster
  namespace: openshift-gitops
spec:
  destination:
    server: https://kubernetes.default.svc
  project: default
  sources:
  - repoURL: 'https://loganmc10.github.io/hypershift-helm'
    chart: deploy-cluster
    targetRevision: 0.1.18
    helm:
      valueFiles:
      - $values/install-config.yaml
  - repoURL: 'https://git.example.com/org/install-configs.git'
    targetRevision: main
    ref: values