> Loadbalancing >

Introduction

In this section, we will deploy a web based application called Komiser and configure an associated Service leveraging the Network Load Balancer to expose the application externally.

Creating your application manifest YAML file

Create a new file called “komiser-with-nlb.yml” with the following contents

apiVersion: v1
kind: Service
metadata:
  name: komiser-with-nlb
  labels:
    name: komiser-with-nlb
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-type: nlb
spec:
  selector:
    app: komiser-with-nlb
  ports:
  - name: http
    protocol: TCP
    port: 80
    targetPort: 3000
  type: LoadBalancer
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: komiser-with-nlb
  labels:
    name: komiser-with-nlb
spec:
  replicas: 
  template:
    metadata:
      labels:
        app: komiser-with-nlb
    spec:
      containers:
      - name: komiser-with-nlb
        image: mlabouardy/komiser:2.1.0
        imagePullPolicy: Always
        ports:
        - containerPort: 3000

Analyze the difference between this manifest and the Classic Load Balancer manifest. We are essentially adding an annotation to the Service metadata telling Kubernetes that we will leverage a Network Load Balancer for the Service
Deploy your application by using kubectl

kubectl create -f komiser-with-nlb.yml

Describe the properties of your newly deployed Service

kubectl describe services

Locate the newly created Service by looking for a Service named “komiser-with-elb” with similar content to the below

Name:                     komiser-with-nlb
Namespace:                default
Labels:                   name=komiser-with-nlb
Annotations:              service.beta.kubernetes.io/aws-load-balancer-type: nlb
Selector:                 app=komiser-with-nlb
Type:                     LoadBalancer
IP:                       10.100.113.207
LoadBalancer Ingress:     a3e243baf7c9811e9b386025ea934319-b301d850bba326d9.elb.eu-west-1.amazonaws.com
Port:                     http  80/TCP
TargetPort:               3000/TCP
NodePort:                 http  32436/TCP
Endpoints:                192.168.69.236:3000
Session Affinity:         None
External Traffic Policy:  Cluster
Events:
  Type    Reason                Age   From                Message
  ----    ------                ----  ----                -------
  Normal  EnsuringLoadBalancer  13m   service-controller  Ensuring load balancer
  Normal  EnsuredLoadBalancer   13m   service-controller  Ensured load balancer

The line “LoadBalancer Ingress” identifies the DNS name of the created Network Load Balancer

LoadBalancer Ingress:     a3e243baf7c9811e9b386025ea934319-b301d850bba326d9.elb.eu-west-1.amazonaws.com

Access the DNS name with your preferred browser and watch the magic happen. Don’t worry if Komiser doesn’t show you any information apart from the standard landing page, we will learn how to fix that further along in the Workshop