Load Balancer

Introduction

This document provides instructions on using Azure Load Balancers with your AKS cluster.
Load balancers can be managed trough kubernetes service deployments.
When you deploy a kubernetes Loadbalancer service, a public or private Azure load balancer is automatically created and managed by the AKS cluster.

Using the public load balancer

To create a public service of type LoadBalancer, copy the manifest below and paste it into a file named public-svc.yaml.

apiVersion: v1
kind: Service
metadata:
  name: public-svc
spec:
  type: LoadBalancer
  ports:
  - port: 80
  selector:
    app: public-app

Deploy the public service manifest using kubectl apply and specify the name of your YAML manifest.

kubectl apply -f public-svc.yaml

Using the private load balancer

To set up an internal load balancer, you can follow these steps:

1. Create a service manifest file named internal-lb.yaml.
2. In the service manifest, specify the service type as LoadBalancer.
3. Add the azure-load-balancer-internal annotation to the manifest to indicate that it’s an internal load balancer.

Here’s an example of how to add the annotation to the manifest:

apiVersion: v1
kind: Service
metadata:
  name: internal-app
  annotations:
    service.beta.kubernetes.io/azure-load-balancer-internal: "true"
spec:
  type: LoadBalancer
  ports:
    - port: 80
  selector:
    app: internal-app

Deploy the internal load balancer using kubectl apply and specify the name of your YAML manifest.

kubectl apply -f internal-lb.yaml

After deploying the manifest, the AKS cluster will create a private azure loadbalancer

Restrict inbound traffic to specific IP ranges

The following manifest uses loadBalancerSourceRanges to specify a new IP range for inbound external traffic.

Here’s an example of how to add the annotation to the manifest:

apiVersion: v1
kind: Service
metadata:
  name: azure-vote-front
spec:
  type: LoadBalancer
  ports:
  - port: 80
  selector:
    app: azure-vote-front
  loadBalancerSourceRanges:
  - <IP_RANGE> # e.g. - 10.1.0.0/16