Use a single load balancer for multi sub-domains in AWS EKS (Kubernetes) ingress rule and reduce…

Summary

The website content describes a cost-saving method for using a single AWS Load Balancer with multiple sub-domains in an AWS EKS (Kubernetes) environment through the AWS Load Balancer controller.

Abstract

The article addresses a common issue faced by AWS EKS users who utilize AWS Load Balancers for ingress with sub-domains, which can become costly due to the need for multiple Load Balancers. The author proposes a solution to use a single Load Balancer for all sub-domains, potentially saving over $20 per Ingress. This approach involves creating a security group with whitelisted IP addresses and attaching it to the Load Balancer, which enhances security and reduces costs. The article provides a step-by-step guide on setting up the security group, configuring the Ingress with the necessary annotations, and ensuring the correct service type is used (NodePort) for the AWS Load Balancer controller to function properly. The guide also includes instructions for creating a service for the deployment, emphasizing the importance of the NodePort service type for the Load Balancer to discover and route traffic to the service.

Opinions

The author suggests that using multiple sub-domains in AWS EKS can be necessary for providing tool access to teams without requiring kubectl installation or direct Kubernetes cluster access.
It is implied that the cost of multiple AWS Load Balancers for sub-domains is a significant concern for AWS EKS users.
The author assumes that readers have the AWS Load Balancer controller installed in their AWS EKS environment and refers them to another article for setup instructions if needed.
The author expresses a preference for creating a dedicated security group for the Load Balancer, which allows for IP whitelisting and applies predefined rules, over the default security group that allows all traffic.
The author emphasizes the importance of having the correct service type (NodePort) for the AWS Load Balancer controller to manage traffic effectively.

Use a single load balancer for multi sub-domains in AWS EKS (Kubernetes) ingress rule and reduce the cost

One of the most frustrating problems using AWS EKS and the AWS Load Balancer controller is the cost of a Load Balancer when using Ingress for a domain and sub-domains.

What I will explain here is a way around that problem and save you $20+ for each Ingress you are using for a sub-domain.

If you thinking why need a lot of subdomains in an AWS EKS cluster and not multi-domains? there can be many reasons for that, and one of them can be you have lots of tools you will give your team access to whiteout there need to install kubectl on the machine and not get access directly into the Kubernetes cluster that way.

The way I can recommend is to create a security group where you whitelist IP addresses and then attach this security group id to your load balancer, I will show that below, I expect you have the AWS Load Balancer controller installed into your AWS EKS else you can read my article about it first.

Create your Ingress with ALB support in AWS EKS

When you are ready you can create an ingress to Kubernetes with a manifest file, you need to change a small thing before you can apply it to your project.

line 9: replace with your certificate arn for your domain, the certificate needs to be in the same region as your AWS EKS cluster.

line 11: Replace with your newly created security group id to be used it applies your rules, if you don't have this line it automatically creates a security group for you and allows all traffic into your select hostname.

line 13: choose the name you will use to group another ingress to this load balancer.

line 17: Write your domain/subdomain here

line 24: write your service name, it's required the services are in the same namespace.

line 26: write your port to the service it received traffic on.

Remember the right service type

If you have forgotten how to create a service for your deployment, I give a sample of it here, remember your service needs to have the type: NodePort the AWS Load Balancer controller can’t find the service if not you use that, so it's very important.

Use a single load balancer for multi sub-domains in AWS EKS (Kubernetes) ingress rule and reduce the cost

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Remember the right service type