Amazon EKS Cluster

This repository contains source code to provision an EKS cluster in AWS using Terraform.

Prerequisites

• AWS account
• AWS profile configured with CLI on local machine
• Terraform
• kubectl

Project Structure

├── README.md
├── eks
|  ├── cluster.tf
|  ├── cluster_role.tf
|  ├── cluster_sg.tf
|  ├── node_group.tf
|  ├── node_group_role.tf
|  ├── node_sg.tf
|  └── vars.tf
├── main.tf
├── provider.tf
├── raw-manifests
|  ├── aws-auth.yaml
|  ├── pod.yaml
|  └── service.yaml
├── variables.tf
└── vpc
   ├── control_plane_sg.tf
   ├── data_plane_sg.tf
   ├── nat_gw.tf
   ├── output.tf
   ├── public_sg.tf
   ├── vars.tf
   └── vpc.tf

Remote Backend State Configuration

To configure remote backend state for your infrastructure, create an S3 bucket and DynamoDB table before running terraform init. In the case that you want to use local state persistence, update the provider.tf accordingly and don't bother with creating an S3 bucket and DynamoDB table.

Create S3 Bucket for State Backend

aws s3api create-bucket --bucket <bucket-name> --region <region> --create-bucket-configuration LocationConstraint=<region>

Create DynamoDB table for State Locking

aws dynamodb create-table --table-name <table-name> --attribute-definitions AttributeName=LockID,AttributeType=S --key-schema AttributeName=LockID,KeyType=HASH --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1

Provision Infrastructure

Review the main.tf to update the node size configurations (i.e. desired, maximum, and minimum). When you're ready, run the following commands:

1. terraform init - Initialize the project, setup the state persistence (whether local or remote) and download the API plugins.
2. terraform plan - Print the plan of the desired state without changing the state.
3. terraform apply - Print the desired state of infrastructure changes with the option to execute the plan and provision.

Connect To Cluster

Using the same AWS account profile that provisioned the infrastructure, you can connect to your cluster by updating your local kube config with the following command: aws eks --region <aws-region> update-kubeconfig --name <cluster-name>

Map IAM Users & Roles to EKS Cluster

If you want to map additional IAM users or roles to your Kubernetes cluster, you will have to update the aws-auth ConfigMap by adding the respective ARN and a Kubernetes username value to the mapRole or mapUser property as an array item.

apiVersion: v1
kind: ConfigMap
metadata:
  name: aws-auth
  namespace: kube-system
data:
  mapRoles: |
    - rolearn: arn:aws:iam::<account-id>:role/<cluster-name>
      username: system:node:{{EC2PrivateDNSName}}
      groups:
        - system:bootstrappers
        - system:nodes
    - rolearn: arn:aws:iam::<account-id>:role/ops-role
      username: ops-role
  mapUsers: |
    - userarn: arn:aws:iam::<account-id>:user/developer-user
      username: developer-user

When you are done with modifications to the aws-auth ConfigMap, you can run kubectl apply -f auth-auth.yaml. An example of this manifest file exists in the raw-manifests directory.

For a more in-depth explanation on this, you can read this post.

Deploy Application

To deploy a simple application to you cluster, redirect to the directory called raw-manifests and apply the pod.yaml and service.yaml manifest files to create a Pod and expose the application with a LoadBalancer Service.

1. kubectl apply -f service.yaml
2. kubectl apply -f pod.yaml