Creating and managing clusters

This topic covers how to create and delete EKS clusters using Eksctl. You can create clusters with a CLI command, or by creating a cluster configuration YAML file.

Creating a simple cluster

Create a simple cluster with the following command:

eksctl create cluster

That will create an EKS cluster in your default region (as specified by your AWS CLI configuration) with one managed nodegroup containing two m5.large nodes.

eksctl now creates a managed nodegroup by default when a config file isn’t used. To create a self-managed nodegroup, pass --managed=false to eksctl create cluster or eksctl create nodegroup.

Considerations

• When creating clusters in us-east-1, you might encounter an UnsupportedAvailabilityZoneException. If this happens, copy the suggested zones and pass the --zones flag, for example: eksctl create cluster --region=us-east-1 --zones=us-east-1a,us-east-1b,us-east-1d. This issue may occur in other regions but is less common. In most cases, you won’t need to use the --zone flag.

Create cluster using config file

You can create a cluster using a config file instead of flags.

First, create cluster.yaml file:

apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: basic-cluster
  region: eu-north-1

nodeGroups:
  - name: ng-1
    instanceType: m5.large
    desiredCapacity: 10
    volumeSize: 80
    ssh:
      allow: true # will use ~/.ssh/id_rsa.pub as the default ssh key
  - name: ng-2
    instanceType: m5.xlarge
    desiredCapacity: 2
    volumeSize: 100
    ssh:
      publicKeyPath: ~/.ssh/ec2_id_rsa.pub

Next, run this command:

eksctl create cluster -f cluster.yaml

This will create a cluster as described.

If you needed to use an existing VPC, you can use a config file like this:

apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: cluster-in-existing-vpc
  region: eu-north-1

vpc:
  subnets:
    private:
      eu-north-1a: { id: subnet-0ff156e0c4a6d300c }
      eu-north-1b: { id: subnet-0549cdab573695c03 }
      eu-north-1c: { id: subnet-0426fb4a607393184 }

nodeGroups:
  - name: ng-1-workers
    labels: { role: workers }
    instanceType: m5.xlarge
    desiredCapacity: 10
    privateNetworking: true
  - name: ng-2-builders
    labels: { role: builders }
    instanceType: m5.2xlarge
    desiredCapacity: 2
    privateNetworking: true
    iam:
      withAddonPolicies:
        imageBuilder: true

The cluster name or nodegroup name must contain only alphanumeric characters (case-sensitive) and hyphens. It must start with an alphabetic character and can’t exceed 128 characters, or you will receive a validation error. For more information, see Create a stack from the CloudFormation console in the AWS CLoudFormation user guide.

Update kubeconfig for new cluster

After the cluster has been created, the appropriate kubernetes configuration will be added to your kubeconfig file. This is, the file that you have configured in the environment variable KUBECONFIG or ~/.kube/config by default. The path to the kubeconfig file can be overridden using the --kubeconfig flag.

Other flags that can change how the kubeconfig file is written:

flag	type	use	default value
--kubeconfig	string	path to write kubeconfig (incompatible with --auto-kubeconfig)	$KUBECONFIG or ~/.kube/config
--set-kubeconfig-context	bool	if true then current-context will be set in kubeconfig; if a context is already set then it will be overwritten	true
--auto-kubeconfig	bool	save kubeconfig file by cluster name	true
--write-kubeconfig	bool	toggle writing of kubeconfig	true

Delete cluster

To delete this cluster, run:

eksctl delete cluster -f cluster.yaml

Warning

Use the --wait flag with delete operations to ensure deletion errors are properly reported.

Without the --wait flag, eksctl will only issue a delete operation to the cluster’s CloudFormation stack and won’t wait for its deletion. In some cases, AWS resources using the cluster or its VPC may cause cluster deletion to fail. If your delete fails or you forget the wait flag, you may have to go to the CloudFormation GUI and delete the eks stacks from there.

Warning

PDB policies may block node removal during cluster deletion.

When deleting a cluster with nodegroups, Pod Disruption Budget (PDB) policies can prevent nodes from being removed successfully. For example, clusters with aws-ebs-csi-driver installed typically have two pods with a PDB policy allowing only one pod to be unavailable at a time, making the other pod unevictable during deletion. To successfully delete the cluster in these scenarios, use the disable-nodegroup-eviction flag to bypass PDB policy checks:

eksctl delete cluster -f cluster.yaml --disable-nodegroup-eviction

See the examples/ directory in the eksctl GitHub repo for more sample config files.

Dry Run

The dry-run feature enables generating a ClusterConfig file that skips cluster creation and outputs a ClusterConfig file that represents the supplied CLI options and contains the default values set by eksctl.

More info can be found on the Dry Run page.