Use RKE to create downstream HA user cluster for Rancher

Hello,

I just installed a HA Rancher Server cluster using RKE (3 nodes) and now need to create a downstream user cluster. As far as I know I have to do that by logging in as Admin in the Rancher console and click on “Add Cluster” and select Create a new Kubernetes cluster from existing nodes (I have my own Ubuntu VMs).

Instead of doing that I was wondering if I can also install a downstream user cluster for Rancher by using RKE and a cluster.yml file? I was looking for that in the Rancher official documentation but did not find anything.

If this is possible is there maybe a sample RKE cluster.yml file available somewhere?

I want my downstream user cluster to be HA too so I will have 7 nodes (3 etcd, 2 controlplane and 2 worker) so I think it would be easier in terms of automation to use RKE.

Thank you very much for your help.

Regards,
J.

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Anyone has an idea if this even possible? Unfortunately this is not documented in the official Rancher doc and I would be thankful if someone could give me a hint here.

Creating a downstream cluster which is HA is adding nodes with the correct roles to the cluster. Automating this is interacting with the API to create the cluster (basically what is sent when you create it in the UI), and then creating the command to run on each node (with the correct role). Our vagrant quickstart has scripts for this (https://github.com/rancher/quickstart/tree/master/vagrant) or the other providers have Terraform examples.

If you want to do it using RKE, you can create a cluster to import and then run the kubectl command with kubeconfig pointing to your cluster. You will lose the ability to fully manage this cluster in Rancher as Imported clusters don’t get the same option to manage as a cluster created in Rancher. How to automate importing clusters is shown in https://forums.rancher.com/t/programmatically-import-cluster-no-web-ui/