---
title: "Load Balancers"
chapter: true
sidebar_position: 30
sidebar_custom_props: {"module": true}
---

:::tip Before you start
Prepare your environment for this section:

```bash timeout=300 wait=30
$ prepare-environment exposing/load-balancer
```

This will make the following changes to your lab environment:
- Install the AWS Load Balancer Controller in the Amazon EKS cluster

You can view the Terraform that applies these changes [here](https://github.com/VAR::MANIFESTS_OWNER/VAR::MANIFESTS_REPOSITORY/tree/VAR::MANIFESTS_REF/manifests/modules/exposing/load-balancer/.workshop/terraform).

:::

Kubernetes uses services to expose pods outside of a cluster. One of the most popular ways to use services in AWS is with the `LoadBalancer` type. With a simple YAML file declaring your service name, port, and label selector, the cloud controller will provision a load balancer for you automatically.

```yaml
apiVersion: v1
kind: Service
metadata:
  name: search-svc # the name of our service
spec:
  type: loadBalancer
  selector:
    app: SearchApp # pods are deployed with the label app=SearchApp
  ports:
    - port: 80
```

This is great because of how simple it is to put a load balancer in front of your application. The service spec has been extended over the years with annotations and additional configuration. A second option is to use an ingress rule and an ingress controller to route external traffic into Kubernetes pods.

![IP mode](./assets/ui-nlb-instance.png)

In this chapter we'll demonstrate how to expose an application running in the EKS cluster to the Internet using a layer 4 Network Load Balancer.