Dennis O'Keeffe

Overview of eksctl

Basic instructions on how to use EKSCTL on the command line.

4 min read

https://eksctl.io/

tl;dr

Clusters

Action Command
Get cluster eksctl get cluster [--name=<name>] [--region=<region>]
Create cluster eksctl create cluster --name=cluster-1 --nodes=4
Write kubeconfig eksctl utils write-kubeconfig --name=<name> [--kubeconfig=<path>] [--set-kubeconfig-context=<bool>]
Delete cluster eksctl delete cluster --name=<name> [--region=<region>]

eksctl create cluster --name=cluster-3 --nodes=4 --auto-kubeconfig

Action Flag Example
Name the cluster --name eksctl create cluster --name=cluster-3
Set default node count --nodes eksctl create cluster --nodes=4
Auto configure kubectl --auto-kubeconfig eksctl create cluster --auto-kubeconfig
Use an auth scaling group --nodes-min, --nodes-max eksctl create cluster --nodes-min=3 --nodes-max=5

Node Groups

Action Command
Get nodegroup eksctl get nodegroup --cluster=<clusterName> [--name=<nodegroupName>]
Create nodegroup eksctl create nodegroup --cluster=<clusterName> [--name=<nodegroupName>]
Scale nodegroup eksctl scale nodegroup --cluster=cluster-1 --nodes=5 ng-a345f4e1
Delete nodegroup eksctl delete nodegroup --cluster=<clusterName> --nodes=<desiredCount> --name=<nodegroupName>
SSH Access Flag --ssh-access
Full ECR Access --full-ecr-access
Enable autoscaling --asg-access

Once clsuter is running, you'll need to add the autoscaler yourself. See https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/aws/README.md.

Creating a cluster using a config file instead of flags

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

First, create cluster.yaml file:

apiVersion: eksctl.io/v1alpha3
kind: ClusterConfig

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

nodeGroups:
  - name: ng-1
    instanceType: m5.large
    desiredCapacity: 10

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/v1alpha3
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

See examples/ directory for more sample config files.

Usage

To download the latest release, run:

curl --silent --location "https://github.com/weaveworks/eksctl/releases/download/latest_release/eksctl_$(uname -s)_amd64.tar.gz" | tar xz -C /tmp
sudo mv /tmp/eksctl /usr/local/bin

Alternatively, macOS users can use Homebrew:

brew install weaveworks/tap/eksctl

You will need to have AWS API credentials configured. What works for AWS CLI or any other tools (kops, Terraform etc), should be sufficient. You can use ~/.aws/credentials file or environment variables. For more information read AWS documentation.

To create a basic cluster, run:

eksctl create cluster

A cluster will be created with default parameters:

  • Exciting auto-generated name, e.g. "fabulous-mushroom-1527688624"
  • 2x m5.large nodes (this instance type suits most common use-cases, and is good value for money)
  • Use official AWS EKS AMI
  • us-west-2 region
  • Dedicated VPC (check your quotas)
  • Using static AMI resolver

Example output

$ eksctl create cluster
[ℹ]  using region us-west-2
[ℹ]  setting availability zones to [us-west-2c us-west-2a us-west-2b]
[ℹ]  subnets for us-west-2c - public:192.168.0.0/19 private:192.168.96.0/19
[ℹ]  subnets for us-west-2a - public:192.168.32.0/19 private:192.168.128.0/19
[ℹ]  subnets for us-west-2b - public:192.168.64.0/19 private:192.168.160.0/19
[ℹ]  using "ami-0ce0ec06e682ee10e" for nodes
[ℹ]  creating EKS cluster "floral-unicorn-1540567338" in "us-west-2" region
[ℹ]  will create 2 separate CloudFormation stacks for cluster itself and the initial nodegroup
[ℹ]  if you encounter any issues, check CloudFormation console or try 'eksctl utils describe-stacks --region=us-west-2 --name=floral-unicorn-1540567338'
[ℹ]  creating cluster stack "eksctl-floral-unicorn-1540567338-cluster"
[ℹ]  creating nodegroup stack "eksctl-floral-unicorn-1540567338-nodegroup-ng-39d54824"
[✔]  all EKS cluster resource for "floral-unicorn-1540567338" had been created
[✔]  saved kubeconfig as "~/.kube/config"
[ℹ]  nodegroup "ng-39d54824" has 0 nodes
[ℹ]  waiting for at least 2 nodes to become ready
[ℹ]  nodegroup "ng-39d54824" has 2 nodes
[ℹ]  node "ip-192-168-71-20.us-west-2.compute.internal" is ready
[ℹ]  node "ip-192-168-25-215.us-west-2.compute.internal" is ready
[ℹ]  kubectl command should work with "~/.kube/config", try 'kubectl get nodes'
[✔]  EKS cluster "floral-unicorn-1540567338" in "us-west-2" region is ready
$