AWS Load Balancer Controller for EKS Cluster

Configuring AWS Load Balancer Controller for EKS Clusters

Overview

The AWS Load Balancer Controller is a Kubernetes controller that automates the provisioning and management of AWS load balancers, including Application Load Balancers (ALB) and Network Load Balancers (NLB), for Kubernetes services. It integrates seamlessly with AWS services to dynamically create and configure load balancers, manage target groups, and route traffic to Kubernetes pods.

This guide covers the step-by-step configuration of the AWS Load Balancer Controller on an EKS cluster, along with a practical example to test the setup.

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Key Concepts

1. Load Balancer Types:
   • ALB: Best for HTTP/HTTPS traffic with advanced routing.
   • NLB: Ideal for low-latency TCP/UDP traffic.
2. Annotations:
   • Service annotations define how AWS load balancers behave (e.g., internal vs. external).
3. IAM Role:
   • Grants the controller permission to interact with AWS APIs.
4. Subnet Tags:
   • Required tags must be added to EKS subnets for proper resource provisioning:
     • Key: kubernetes.io/role/internal-elb
     • Value: 1

Prerequisites

Before you begin, ensure the following:

1. EKS Cluster: A functioning EKS cluster is required.
2. Helm: Install Helm to deploy the AWS Load Balancer Controller.
3. IAM Permissions: Ensure administrative privileges for creating roles and policies.
4. Tagged Subnets: Add the following tag to all EKS subnets:
   • Key: kubernetes.io/role/internal-elb
   • Value: 1

Step-by-Step Configuration

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Step 1: Create IAM Role

1. Download the IAM policy:

   curl -O https://raw.githubusercontent.com/kubernetes-sigs/aws-load-balancer-controller/v2.7.2/docs/install/iam_policy.json
   

2. Create the IAM policy

   aws iam create-policy \
    --policy-name AWSLoadBalancerControllerIAMPolicy \
    --policy-document file://iam_policy.json
   

3. Create the IAM role and associate it with the EKS cluster

   eksctl create iamserviceaccount \
    --cluster=my-cluster \
    --namespace=kube-system \
    --name=aws-load-balancer-controller \
    --role-name AmazonEKSLoadBalancerControllerRole \
    --attach-policy-arn arn:aws:iam::111122223333:policy/AWSLoadBalancerControllerIAMPolicy \
    --approve
   

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   Step 2: Install AWS Load Balancer Controller

4. Add the Helm chart repository:

   helm repo add eks https://aws.github.io/eks-charts
   helm repo update eks
   

5. Install the controller

   helm install aws-load-balancer-controller eks/aws-load-balancer-controller \
    -n kube-system \
    --set clusterName=my-cluster \
    --set serviceAccount.create=false \
    --set serviceAccount.name=aws-load-balancer-controller \
    --set region=region-code \
    --set vpcId=vpc-xxxxxxxx
   

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   Step 3: Verify Installation

   Check the status of the controller and its pods

   kubectl get deployment -n kube-system aws-load-balancer-controller
   kubectl get pods -n kube-system
   

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   Testing the Setup

6. Create a Sample nginx Deployment and LoadBalancer Service ```bash apiVersion: apps/v1 kind: Deployment metadata: name: nginx labels: app: nginx spec: replicas: 1 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx ports: - containerPort: 80

apiVersion: v1 kind: Service metadata: name: nginx-service annotations: service.beta.kubernetes.io/aws-load-balancer-type: external service.beta.kubernetes.io/aws-load-balancer-nlb-target-type: ip service.beta.kubernetes.io/aws-load-balancer-scheme: internal service.beta.kubernetes.io/aws-load-balancer-name: test-nlb spec: selector: app: nginx ports: - port: 80 targetPort: 80 protocol: TCP type: LoadBalancer

2. Apply the manifest
 ```bash
kubectl apply -f nginx.yaml

1. Verify the LoadBalancer service

   kubectl get svc nginx-service
   

2. Test the LoadBalancer

   curl <external-endpoint>
   

   Cleanup To remove all resources

   kubectl delete -f nginx.yaml
   aws elbv2 delete-target-group --target-group-arn <target-group-arn>
   

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   Summary

   This guide demonstrated how to configure and test the AWS Load Balancer Controller for Kubernetes services in an EKS cluster. By automating the creation and management of load balancers, the controller enhances the scalability and reliability of Kubernetes workloads while reducing operational overhead.

For more information, refer to the AWS Load Balancer Controller Documentation.