Cluster Autoscaler

If you have not already done so, make sure your cluster meets the package prerequisites. Be sure to refer to the troubleshooting guide in the event of a problem.

Choose a Deployment Approach

Each Cluster Autoscaler instance can target one cluster for autoscaling.

There are three ways to deploy a Cluster Autoscaler instance:

1. Cluster Autoscaler deployed in the management cluster to autoscale the management cluster itself
2. Cluster Autoscaler deployed in the management cluster to autoscale a remote workload cluster
3. Cluster Autoscaler deployed in the workload cluster to autoscale the workload cluster itself

To read more about the tradeoffs of these different approaches, see here .

Install Cluster Autoscaler in management cluster

1. Ensure you have configured at least one WorkerNodeGroup in your cluster to support autoscaling as outlined here

2. Generate the package configuration

   eksctl anywhere generate package cluster-autoscaler --cluster <cluster-name> > cluster-autoscaler.yaml
   

3. Add the desired configuration to cluster-autoscaler.yaml

   Please see complete configuration options for all configuration options and their default values.

   Example package file configuring a cluster autoscaler package to run in the management cluster.

   Note: Here, the <cluster-name> value represents the name of the management or workload cluster you would like to autoscale.

   apiVersion: packages.eks.amazonaws.com/v1alpha1
   kind: Package
   metadata:
     name: cluster-autoscaler
     namespace: eksa-packages-<cluster-name>
   spec:
     packageName: cluster-autoscaler
     targetNamespace: <namespace-to-install-component>
     config: |-
         cloudProvider: "clusterapi"
         autoDiscovery:
           clusterName: "<cluster-name>"      
   

4. Install Cluster Autoscaler

   eksctl anywhere create packages -f cluster-autoscaler.yaml
   

5. Validate the installation

   eksctl anywhere get packages --cluster <cluster-name>
   

   Example command output

   NAMESPACE                  NAME                          PACKAGE              AGE   STATE       CURRENTVERSION                                               TARGETVERSION                                                         DETAIL
   eksa-packages-mgmt-v-vmc   cluster-autoscaler            cluster-autoscaler   18h   installed   9.21.0-1.21-147e2a701f6ab625452fe311d5c94a167270f365         9.21.0-1.21-147e2a701f6ab625452fe311d5c94a167270f365 (latest)
   

Update

To update package configuration, update cluster-autoscaler.yaml file, and run the following command:

eksctl anywhere apply package -f cluster-autoscaler.yaml

Upgrade

Cluster Autoscaler will automatically be upgraded when a new bundle is activated.

Uninstall

To uninstall Cluster Autoscaler, simply delete the package

eksctl anywhere delete package --cluster <cluster-name> cluster-autoscaler

Install Cluster Autoscaler in workload cluster

A few extra steps are required to install cluster autoscaler in a workload cluster instead of the management cluster.

First, retrieve the management cluster’s kubeconfig secret:

kubectl -n eksa-system get secrets <management-cluster-name>-kubeconfig -o yaml > mgmt-secret.yaml

Update the secret’s namespace to the namespace in the workload cluster that you would like to deploy the cluster autoscaler to. Then, apply the secret to the workload cluster.

kubectl --kubeconfig /path/to/workload/kubeconfig apply -f mgmt-secret.yaml

Now apply this package configuration to the management cluster:

apiVersion: packages.eks.amazonaws.com/v1alpha1
kind: Package
metadata:
    name: workload-cluster-autoscaler
    namespace: eksa-packages-<workload-cluster-name>
spec:
    packageName: cluster-autoscaler
    targetNamespace: <workload-cluster-namespace-to-install-components>
    config: |-
        cloudProvider: "clusterapi"
        autoDiscovery:
            clusterName: "<workload-cluster-name>"
        clusterAPIMode: "incluster-kubeconfig"
        clusterAPICloudConfigPath: "/etc/kubernetes/value"
        extraVolumeSecrets:
            cluster-autoscaler-cloud-config:
                mountPath: "/etc/kubernetes"
                name: "<management-cluster-name>-kubeconfig"