This is the multi-page printable view of this section. Click here to print.

Return to the regular view of this page.

Cluster Autoscaler Configuration

Cluster Autoscaler is a component that automatically adjusts the size of a Kubernetes Cluster so that all pods have a place to run and there are no unneeded nodes.

Configuration options for Cluster Autoscaler

1 - Cluster Autoscaler

Install/upgrade/uninstall Cluster Autoscaler

If you have not already done so, make sure your EKS Anywhere cluster meets the package prerequisites.

Refer to the troubleshooting guide in the event of a problem.

Enable Cluster Autoscaling

  1. Ensure you have configured at least one worker node group in your cluster specification to enable autoscaling as outlined in Autoscaling configuration. Cluster Autoscaler only works on node groups with an autoscalingConfiguration set:

    apiVersion: anywhere.eks.amazonaws.com/v1alpha1
    kind: Cluster
    metadata:
      name: <cluster-name>
    spec:
      ...
      workerNodeGroupConfigurations:
        - autoscalingConfiguration:
            minCount: 1
            maxCount: 5
          machineGroupRef:
            kind: VSphereMachineConfig
            name: <worker-machine-config-name>
          count: 1
          name: md-0
    
  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. See configuration options for all configuration options and their default values. See below for an example package file configuring a Cluster Autoscaler package.

    apiVersion: packages.eks.amazonaws.com/v1alpha1
    kind: Package
    metadata:
      name: cluster-autoscaler-<cluster-name>
      namespace: eksa-packages-<cluster-name>
    spec:
      packageName: cluster-autoscaler
      targetNamespace: default
      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>
    
    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)
    

    To verify that autoscaling works, apply the deployment below. You must continue scaling pods until the deployment has pods in a pending state. This is when Cluster Autoscaler will begin to autoscale your machine deployment. This process may take a few minutes.

    kubectl apply -f https://raw.githubusercontent.com/aws/eks-anywhere/d8575bbd2a85a6c6bbcb1a54868cf7790df56a63/test/framework/testdata/hpa_busybox.yaml
    kubectl scale deployment hpa-busybox-test --replicas 100
    

Update

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

eksctl anywhere apply package -f cluster-autoscaler.yaml

Update Worker Node Group Autoscaling Configuration

It is possible to change the autoscaling configuration of a worker node group by updating the autoscalingConfiguration in your cluster specification and running a cluster upgrade.

Upgrade

The Cluster Autoscaler can be upgraded by PackageController’s activeBundle field to a newer version. The curated packages bundle contains the SHAs of the images and helm charts associated with a particular package. When a new version is activated, the Package Controller will reconcile all active packages to their newest versions as defined in the bundle. The Curated Packages Controller automatically polls the bundle repository for new bundle resources. The curated packages controller automatically polls for the latest bundle, but requires the activeBundle field on the PackageController resource to be updated before a new bundle will take effect and upgrade the resources.

Uninstall

To uninstall Cluster Autoscaler, delete the package

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

2 - v9.21.0

Configuring Cluster Autoscaler in EKS Anywhere package spec

Parameter Description Default
General
cloudProvider Cluster Autoscaler cloud provider. This should always be clusterapi.
Example:
cloudProvider: “clusterapi”
“clusterapi”
autoDiscovery.clusterName Name of the kubernetes cluster this autoscaler package should autoscale.
Example:
autoDiscovery.clusterName: “mgmt-cluster”
false
clusterAPIMode Where Cluster Autoscaler should look for a kubeconfig to communicate with the cluster it will manage. See https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/clusterapi/README.md#connecting-cluster-autoscaler-to-cluster-api-management-and-workload-clusters
Example:
clusterAPIMode: “incluster-kubeconfig”
“incluster-incluster”
clusterAPICloudConfigPath Path to kubeconfig for connecting to Cluster API Management Cluster, only used if clusterAPIMode=kubeconfig-kubeconfig or incluster-kubeconfig
Example:
clusterAPICloudConfigPath: “/etc/kubernetes/value”
“/etc/kubernetes/mgmt-kubeconfig”
extraVolumeSecrets Additional volumes to mount from Secrets.
Example:
extraVolumeSecrets: {}
{}