Internal LoadBalancer

Experience seamless internal load balancing for your Apache HTTP Server deployment on Kubernetes! In this deployment, we'll create a robust and scalable setup using a Deployment and an internal LoadBalancer-type Service.

Key Steps:

• Step 1: Apache HTTP Server Deployment:

  • Deploy the Apache HTTP Server using a Kubernetes Deployment, ensuring scalable and reliable operation.

• Step 2: Internal LoadBalancer Service:

  • Leverage the Service type LoadBalancer to create an internal load balancer, making your Apache HTTP Server accessible within the Kubernetes cluster.

• Step 3: Verification with Ubuntu Pod:

  • Validate the functionality of your internal load balancer by - creating an Ubuntu Pod within the same cluster.
  • Test connectivity to the Apache HTTP Server service, ensuring that the internal load balancer is working correctly.

Why Internal Load Balancing?

• Securely expose your services within your Kubernetes cluster without external access.
• Enhance isolation and privacy by utilizing internal IP addresses.
• Perfect for scenarios where your Apache HTTP Server service is intended for internal communication within your infrastructure.

Get Started

Deploy your Apache HTTP Server with the provided manifest. This service will be accessible via the internal load balancer on port 8080.

File internal-loadbalancer.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: internal-http-apache2-deployment
spec:
  replicas: 2
  selector:
    matchLabels:
      app: apache2
  template:
    metadata:
      labels:
        app: apache2
    spec:
      containers:
        - name: apache2
          image: httpd
          ports:
            - containerPort: 80
---

apiVersion: v1
kind: Service
metadata:
  name: internal-http-apache2-service
  annotations:
    vks.vngcloud.vn/internal-load-balancer: "true"  # MUST set like this to create an internal loadbalancer
spec:
  selector:
    app: apache2
  type: LoadBalancer                                # MUST set like this to create an internal loadbalancer
  ports:
    - name: http
      protocol: TCP
      port: 8080                                    # CAN be accessed via this port with other service in the same VPC
      targetPort: 80

Apply the internal-loadbalancer.yaml manifest:

kubectl apply -f internal-loadbalancer.yaml

Users can follow the progress of this load balancer is being created by access the Load Balancer dashboard on the VNG CLOUD portal:

Wait for the load balancer to be created successfully, users can check the status of loadbalancer, listeners, pools, and its members.

Spin up an Ubuntu Pod to verify and test the internal load balancer using file ubuntu-pod.yaml.

cat <<EOF | kubectl apply -f-
apiVersion: v1
kind: Pod
metadata:
  name: ubuntu-pod
spec:
  hostNetwork: true
  containers:
  - name: ubuntu-container
    image: ubuntu:latest
    command: ["sleep", "infinity"]
EOF

Verify the necessary resources are created successfully:

kubectl get pods -owide

Make GET request to the internal IP address of the load balancer, you can get the internal IP address of the load balancer by accessing the Load Balancer dashboard on the VNG CLOUD portal:

or by executing the following command:

kubectl get svc -owide

kubectl exec -it ubuntu-pod -- bash 

# inside the ubuntu-pod
apt update && apt install curl -y
curl http://<INTERNAL_LOADBALANCER_IP>:8080

Now, you can clean up the resources created in this lab by executing the following command:

kubectl delete pod ubuntu-pod --force
kubectl delete -f internal-loadbalancer.yaml

Verify the resources are deleted successfully:

kubectl get pods -owide
kubectl get svc -owide