How to Build EKS Cluster Across AWS Local Zones with CDK: Complete Guide
By Braincuber Team
Published on March 17, 2026
AWS Local Zones are revolutionizing how we deploy applications closer to end-users, providing the same high availability and reliability as AWS Regions but with significantly lower latency. When combined with Amazon EKS and AWS CDK, you can build sophisticated Kubernetes clusters that deliver sub-10ms latency for latency-sensitive applications. This complete guide will walk you through building an EKS cluster across AWS Local Zones using infrastructure as code, ensuring repeatable deployments and optimal performance.
What You'll Learn:
- Understanding AWS Local Zones and their benefits for low-latency applications
- Setting up AWS CDK project with proper dependencies and configuration
- Creating VPC with Local Zone subnets for optimal network topology
- Building EKS cluster with Local Zone worker nodes
- Implementing Auto Scaling Groups for high availability
- Deploying infrastructure using AWS CDK best practices
- Configuring security groups and networking for production workloads
- Testing and validating your Local Zone EKS deployment
Understanding AWS Local Zones
AWS Local Zones are a new type of infrastructure that places compute, storage, and networking services within metropolitan areas, typically 10-50ms from end-users. They're designed for applications requiring ultra-low latency such as real-time gaming, video streaming, and financial trading.
Ultra-Low Latency
Sub-10ms latency to end-users, 10x faster than traditional regional deployments. Perfect for latency-sensitive applications.
High Availability
Same availability and reliability as AWS Regions. Automatic failover and redundancy built into the infrastructure.
Performance: 10ms latency vs 100ms+ regional
Use Cases: Gaming, streaming, ML inference, financial trading
Cost: Similar pricing to regional deployments
Integration: Seamless with AWS services
Prerequisites and Setup
Before we begin building our EKS cluster, ensure you have the following prerequisites in place:
AWS Account Setup
AWS account with permissions to create resources in AWS Local Zones and Wavelength. Ensure you have appropriate IAM permissions for EKS, EC2, and VPC management.
AWS CDK Installation
AWS Cloud Development Kit installed locally. Install via npm: npm install -g aws-cdk. Configure with aws configure.
AWS CLI Configuration
AWS Command Line Interface installed and configured with your credentials. Required for CDK deployment and Local Zone management.
Local Zone Opt-in
Opt-in to AWS Local Zones in your target region. Currently available in select US cities like Los Angeles, New York, and others.
Step 1: Create AWS Local Zone
The first step is to opt-in to AWS Local Zones in the region of your choice. This enables you to deploy resources within metropolitan areas for ultra-low latency.
1. Navigate to AWS Console
2. Select target region (e.g., us-west-2)
3. Opt-in to Local Zones service
4. Wait for activation (usually immediate)
5. Verify zone availability in console
Available Local Zones
Current locations include Los Angeles (us-west-2-las-1a), New York (us-east-1-nyc-1a), Dallas (us-east-1-dfw-1a), and more. Check AWS documentation for the latest availability as zones are continuously expanding.
Step 2: Create CDK Project
Now let's create a new CDK project to define our infrastructure as code. This approach ensures repeatable deployments and version control.
Initialize CDK Project
Create new directory and initialize CDK project with JavaScript support. This sets up the basic project structure with necessary configuration files.
Install Dependencies
Install required AWS CDK modules for EKS, EC2, and Auto Scaling. These provide the building blocks for our Kubernetes infrastructure.
Configure Environment
Set up environment variables for AWS account and region. This ensures CDK deploys to the correct account and Local Zone.
mkdir eks-local-zone
cd eks-local-zone
cdk init --language=javascript
npm install
touch .env
Step 3: Create VPC with Local Zone Subnets
We need to create a Virtual Private Cloud (VPC) with both regular subnets and Local Zone subnets. This provides the network foundation for our EKS cluster.
CIDR: 10.0.0.0/16 (65,536 IPs)
Subnets: 2 private + 1 public (Local Zone)
AZ Coverage: 2 regular AZs + 1 Local Zone
Network: Isolated, secure, high-performance
const cdk = require('aws-cdk-lib');
const ec2 = require('@aws-cdk/aws-ec2');
class VPCStack extends cdk.Stack {
constructor(scope, id, props) {
super(scope, id, props);
const vpc = new ec2.Vpc(this, 'VPC', {
cidr: '10.0.0.0/16',
maxAzs: 2,
subnetConfiguration: [
{ cidrMask: 24, name: 'Public', subnetType: ec2.SubnetType.PUBLIC },
{ cidrMask: 24, name: 'Private', subnetType: ec2.SubnetType.PRIVATE }
]
});
}
}
Step 4: Create EKS Cluster
Now we'll create the Amazon EKS cluster using our VPC. The cluster will span across regular availability zones and include Local Zone worker nodes for optimal performance.
Cluster Configuration
Define EKS cluster with Kubernetes version 1.21, no default capacity (we'll add worker nodes separately), and cluster name for identification.
VPC Integration
Connect the EKS cluster to our VPC. This ensures proper network isolation and connectivity between control plane and worker nodes.
Local Zone Integration
Configure the cluster to use Local Zone subnets. This enables deployment of latency-sensitive workloads closer to end-users.
const eks = require('@aws-cdk/aws-eks');
class EKSStack extends cdk.Stack {
constructor(scope, id, props) {
super(scope, id, props);
const cluster = new eks.Cluster(this, 'EKSCluster', {
vpc: vpc,
defaultCapacity: 0,
version: '1.21',
clusterName: 'local-zone-eks-demo-cluster'
});
}
}
Step 5: Create Worker Nodes
Worker nodes are where your containerized applications will actually run. We'll create an Auto Scaling Group with Local Zone instances for high availability and optimal performance.
Launch Template
Create EC2 launch template with EKS-optimized AMI, public IP assignment, and bootstrap script to join nodes to the cluster.
Auto Scaling Group
Configure ASG with desired capacity, health checks, and integration with Local Zone subnets for automatic scaling based on demand.
Instance: t3.medium (2 vCPU, 4GB RAM)
AMI: Amazon Linux 2 (EKS-optimized)
Subnet: Local Zone (us-west-2-las-1a)
Scaling: Manual (1 node) + Auto Scaling
Bootstrap: /etc/eks/bootstrap.sh
Step 6: Deploy the CDK Application
With all our infrastructure defined, let's deploy the CDK application to create our EKS cluster across AWS Local Zones.
Bootstrap CDK
Bootstrap the CDK app in your AWS account. This creates the CloudFormation execution role and S3 bucket for deployment artifacts.
Deploy Infrastructure
Deploy the CDK stacks to create VPC, EKS cluster, and worker nodes. Monitor the deployment progress in the AWS Console.
Configure kubectl
Update your kubeconfig file to connect to the new EKS cluster. Verify connectivity with kubectl get nodes.
cdk bootstrap
cdk deploy
aws eks update-kubeconfig
kubectl get nodes
kubectl get pods -A
Testing and Validation
After deployment, it's crucial to test your EKS cluster to ensure everything is working correctly:
| Test | Command | Expected Result |
|---|---|---|
| Cluster Status | kubectl get nodes | List all worker nodes with Ready status |
| Pod Deployment | kubectl run nginx --image=nginx | Pod runs successfully in Local Zone |
| Service Exposure | kubectl expose deployment nginx --port=80 | Load balancer created with public IP |
| Latency Test | ping [load-balancer-ip] | <10ms response time from Local Zone |
Validation Checklist
✅ EKS control plane running
✅ Worker nodes joined cluster
✅ Pods can schedule to Local Zone
✅ Services accessible via load balancer
✅ Latency <10ms from Local Zone
✅ Auto Scaling functional
Best Practices and Optimization
Follow these best practices to optimize your Local Zone EKS deployment for production workloads:
Security Hardening
Implement proper IAM roles, security groups, and network ACLs. Use private subnets for worker nodes and bastion hosts for access.
Cost Optimization
Use Spot Instances for worker nodes, implement auto-scaling schedules, and choose appropriate instance types based on workload requirements.
| Optimization Area | Recommendation | Expected Savings |
|---|---|---|
| Instance Selection | Use t3.large for production workloads | Better CPU-to-memory ratio |
| Auto Scaling | Scale based on CPU/memory metrics | 40-60% cost reduction |
| Storage | Use gp3 for general workloads | 20% cost vs io1 |
| Networking | Use NAT gateways for internet access | Improved security, lower costs |
Frequently Asked Questions
What's the difference between Local Zones and Wavelength?
Local Zones provide general compute services in metropolitan areas, while Wavelength is specifically designed for 5G edge computing and streaming workloads. Local Zones offer broader instance types and use cases.
How much does Local Zones cost?
Local Zones pricing is similar to regional deployments with a small premium (typically 10-15% more). The cost is offset by reduced data transfer costs and improved user experience.
Can I mix Local Zones with regular AZs?
Yes, EKS clusters can span across both Local Zones and regular availability zones. This provides flexibility for different workload types within the same cluster.
What happens if Local Zone goes down?
EKS provides automatic failover. Workloads can be rescheduled to regular availability zones or other Local Zones if available, ensuring high availability.
How do I monitor Local Zone performance?
Use CloudWatch metrics, X-Ray tracing, and VPC Flow Logs. Set up alarms for latency thresholds and node health to ensure optimal performance.
Need Help Building Production EKS Clusters?
Our experts can help you design and deploy EKS clusters across AWS Local Zones, optimize for cost and performance, and implement best practices for production workloads.