Offload Reconciliation of NLB to LBC Using Annotation¶

In this demo, we will use service.beta.kubernetes.io/aws-load-balancer-type: external annotation to offload the reconciliation of Network Load Balancer (NLB) to AWS Load Balancer Controller (LBC).

Docker Images¶

Here is the Docker Image used in this tutorial: reyanshkharga/nodeapp:v1

Step 1: Create a Deployment¶

First, let's create a deployment as follows:

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apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-deployment
spec:
  replicas: 2
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      containers:
      - name: nodeapp
        image: reyanshkharga/nodeapp:v1
        ports:
          - containerPort: 5000

Apply the manifest to create the deployment:

kubectl apply -f my-deployment.yml

Verify deployment and pods:

# List deployments
kubectl get deployments

# List pods
kubectl get pods

Step 2: Create a Service¶

Now, let's create a LoadBalancer service but this time we'll offload the reconciliation of NLB to LBC using .spec.loadBalancerClass field.

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apiVersion: v1
kind: Service
metadata:
  name: nlb-service
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-name: my-nlb
    service.beta.kubernetes.io/aws-load-balancer-type: external
    service.beta.kubernetes.io/aws-load-balancer-nlb-target-type: instance # Must specify this annotation
    service.beta.kubernetes.io/aws-load-balancer-scheme: internet-facing # Default is internal
spec:
  type: LoadBalancer
  selector:
    app: demo
  ports:
    - port: 80
      targetPort: 5000

service.beta.kubernetes.io/aws-load-balancer-scheme: internet-facing

Apply the manifest to create the service:

kubectl apply -f my-service.yml

Verify service:

kubectl get svc

Step 3: Verify the Network Load Balancer (NLB) in AWS Console¶

Visit AWS Console and verify that a network load balancer (NLB) was created.

Also, verify that the NLB was created by AWS Load Balancer Controller. You can check the events in the logs as follows:

kubectl logs -f deploy/aws-load-balancer-controller -n aws-load-balancer-controller --all-containers=true

Step 4: Access App Via Network Load Balancer DNS¶

Once the load balancer is in Active state, you can hit the load balancer DNS and verify if everything is working properly.

Access the load balancer DNS by entering it in your browser. You can get the load balancer DNS either from the AWS console or the service configuration.

Try accessing the following paths:

# Root path
<nlb-dns>/

# Health path
<nlb-dns>/health

# Random generator path
<nlb-dns>/random

Clean Up¶

Assuming your folder structure looks like the one below:

|-- manifests
│   |-- my-deployment.yml
│   |-- my-service.yml

Let's delete all the resources we created:

kubectl delete -f manifests/