EKS cluster creation in AWS - Commands & Configuration

Introduction

Creating an EKS cluster lets you run and manage containerized applications on AWS easily. It solves the problem of setting up and managing Kubernetes infrastructure by automating the control plane and worker nodes.

When you want to deploy containerized applications on AWS with Kubernetes without managing the control plane yourself

When you need a scalable and secure environment for running microservices

When you want to integrate your Kubernetes workloads with other AWS services like IAM and CloudWatch

When you want to avoid the complexity of setting up Kubernetes masters and focus on your applications

When you want a managed Kubernetes service that handles upgrades and availability automatically

Config File - cluster.yaml

cluster.yaml

apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig
metadata:
  name: example-cluster
  region: us-east-1
nodeGroups:
  - name: ng-1
    instanceType: t3.medium
    desiredCapacity: 2
    ssh:
      allow: true
      publicKeyName: example-key

This file defines the EKS cluster configuration using eksctl format.

• metadata.name: The cluster name.
• metadata.region: AWS region to create the cluster.
• nodeGroups: Defines worker nodes with instance type and count.
• ssh: Allows SSH access to nodes using the specified key.

Commands

This command creates the EKS cluster and worker nodes as defined in the cluster.yaml file. It automates the setup of control plane and node groups.

Terminal

eksctl create cluster -f cluster.yaml

Expected Output

[ℹ]  eksctl version 0.140.0

[ℹ]  using region us-east-1

[ℹ]  setting availability zones to [us-east-1a us-east-1b us-east-1c]

[ℹ]  nodegroup "ng-1" will use "ami-0c55b159cbfafe1f0" [AmazonLinux2/1.21]

[ℹ]  creating EKS cluster "example-cluster" in "us-east-1" region

[ℹ]  1 nodegroup(s) (ng-1) were included (based on the include/exclude rules)

[ℹ]  will create a CloudFormation stack for cluster itself and 1 nodegroup(s)

[✔]  all cluster resource for "example-cluster" created

[ℹ]  nodegroup "ng-1" has 2 node(s)

[✔]  EKS cluster "example-cluster" in "us-east-1" region is ready

→

-f - Specifies the cluster configuration file to use

This command verifies that the worker nodes are registered and ready in the Kubernetes cluster.

Terminal

kubectl get nodes

Expected Output

NAME                                           STATUS   ROLES    AGE   VERSION

ip-192-168-10-1.us-east-1.compute.internal    Ready    <none>   5m    v1.21.2-eks-0389ca3

ip-192-168-10-2.us-east-1.compute.internal    Ready    <none>   5m    v1.21.2-eks-0389ca3

This command updates your local kubeconfig file to connect kubectl to the new EKS cluster.

Terminal

aws eks update-kubeconfig --name example-cluster --region us-east-1

Expected Output

Added new context arn:aws:eks:us-east-1:123456789012:cluster/example-cluster to /home/user/.kube/config

→

--name - Specifies the EKS cluster name

→

--region - Specifies the AWS region of the cluster

Key Concept

If you remember nothing else from this pattern, remember: eksctl simplifies EKS cluster creation by automating control plane and node setup with a simple config file.

Common Mistakes

Not updating kubeconfig after cluster creation

kubectl commands will fail because they don't know how to connect to the new cluster

Run 'aws eks update-kubeconfig --name example-cluster --region us-east-1' to configure kubectl

Using an incorrect or missing SSH key name in the config file

You won't be able to SSH into worker nodes if needed

Ensure the SSH key name exists in your AWS account and matches the 'publicKeyName' in the config

Skipping verification of node status with 'kubectl get nodes'

You won't know if worker nodes are ready and connected to the cluster

Always run 'kubectl get nodes' to confirm nodes are in Ready status

Summary

Create an EKS cluster using eksctl with a YAML config file defining cluster and node details.

Update your local kubeconfig to connect kubectl to the new cluster.

Verify worker nodes are ready using 'kubectl get nodes' to ensure the cluster is operational.