Added section for imported EKS cluster parameters; also added managed node group prereq for imported EKS clusters

content/rancher/v2.6/en/cluster-provisioning/registered-clusters/_index.md

@@ -17,13 +17,13 @@ The control that Rancher has to manage a registered cluster depends on the type
 
 # Prerequisites
 
-## Kubernetes Node Roles
+### Kubernetes Node Roles
 
 Registered RKE Kubernetes clusters must have all three node roles - etcd, controlplane and worker. A cluster with only controlplane components cannot be registered in Rancher.
 
 For more information on RKE node roles, see the [best practices.]({{<baseurl>}}/rancher/v2.6/en/cluster-provisioning/production/#cluster-architecture)
 
-## Permissions
+### Permissions
 
 If your existing Kubernetes cluster already has a `cluster-admin` role defined, you must have this `cluster-admin` privilege to register the cluster in Rancher.
 
@@ -41,6 +41,10 @@ By default, GKE users are not given this privilege, so you will need to run the
 
 If you are registering a K3s cluster, make sure the `cluster.yml` is readable. It is protected by default. For details, refer to [Configuring a K3s cluster to enable importation to Rancher.](#configuring-a-k3s-cluster-to-enable-registration-in-rancher)
 
+### EKS Clusters
+
+EKS clusters must have at least one managed node group to be imported into Rancher or provisioned from Rancher successfully.
+
 # Registering a Cluster
 
 1. Click **☰ > Cluster Management**.
@@ -82,6 +86,32 @@ The option can also be specified using the environment variable `K3S_KUBECONFIG_
 $ curl -sfL https://get.k3s.io | K3S_KUBECONFIG_MODE="644" sh -s -
 ```
 
+### Configuring an Imported EKS Cluster with Terraform
+
+You should define **only** the minimum fields that Rancher requires when importing an EKS cluster with Terraform. This is important as Rancher will overwrite what was in the EKS cluster with any config that the user has provided, whether that config is valid or not.
+
+The minimum config fields required by Rancher to import EKS clusters with Terraform using `eks_config_v2` are as follows:
+
+- cloud_credential_id
+- name
+- region
+- imported (this field should always be set to `true` for imported clusters)
+
+Example YAML configuration for imported EKS clusters:
+
+```
+resource "rancher2_cluster" "my-eks-to-import" {
+  name        = "my-eks-to-import"
+  description = "Terraform EKS Cluster"
+  eks_config_v2 {
+    cloud_credential_id = rancher2_cloud_credential.aws.id
+    name                = var.aws_eks_name
+    region              = var.aws_region
+    imported            = true
+  }
+}
+```
+
 # Management Capabilities for Registered Clusters
 
 The control that Rancher has to manage a registered cluster depends on the type of cluster.