Building a Web Server Cluster with Load Balancing on Google Cloud Platform

In this guide, we will learn how to set up a web server system that can handle more users on Google Cloud Platform (GCP). We will use Compute Engine to make web server computers (called instances). We will also use load balancers to share the website traffic so no server gets too busy.

Steps we will do:

Create three web server virtual machines.
Set up firewall rules to allow traffic.
Configure the network load balancer and the HTTP load balancer to share traffic between servers.

This guide will help you finish the GSP313 Google Cloud lab called "Implement Load Balancing on Compute Engine: Challenge Lab.

Task 1. Create multiple web server instances

The first task is to make three Debian VM instances (web1, web2, web3) using GCP Compute Engine. Each VM will run Apache and show a simple webpage that tells which server it is.

Property	Value
Region	us-west1
Zone	us-west1-b
Series	E2
Machine Type	e2-small
Image Family	debian-12
Image Project	debian-cloud
Network Tag	network-lb-tag

Startup Script

Each VM has a startup script that installs Apache and makes a simple HTML page.

      '#!/bin/bash
      apt-get update
      apt-get install apache2 -y
      service apache2 restart
      echo "
<h3>Web Server: web<num></num>
</h3>" | tee /var/www/html/index.html'

1. Create VM web1

gcloud compute instances create web1 \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --zone=us-west1-b \
  --machine-type=e2-small \
  --tags=network-lb-tag \
  --image-family=debian-12 \
  --image-project=debian-cloud \
  --metadata startup-script='#!/bin/bash
apt-get update
apt-get install apache2 -y
service apache2 restart
echo "<h3>Web Server: web1</h3>" | tee /var/www/html/index.html'

2. Create VM web2

gcloud compute instances create web2 \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --zone=us-west1-b \
  --machine-type=e2-small \
  --tags=network-lb-tag \
  --image-family=debian-12 \
  --image-project=debian-cloud \
  --metadata startup-script='#!/bin/bash
apt-get update
apt-get install apache2 -y
service apache2 restart
echo "<h3>Web Server: web2</h3>" | tee /var/www/html/index.html'

3. Create VM web3

gcloud compute instances create web3 \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --zone=us-west1-b \
  --machine-type=e2-small \
  --tags=network-lb-tag \
  --image-family=debian-12 \
  --image-project=debian-cloud \
  --metadata startup-script='#!/bin/bash
apt-get update
apt-get install apache2 -y
service apache2 restart
echo "<h3>Web Server: web3</h3>" | tee /var/www/html/index.html'

4. Create Firewall Rule for HTTP

gcloud compute firewall-rules create www-firewall-network-lb \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --network=default \
  --action=ALLOW \
  --rules=tcp:80 \
  --source-ranges=0.0.0.0/0 \
  --target-tags=network-lb-tag \
  --description="Allow HTTP traffic to instances with network-lb-tag"

Task 2. Configure Network Load Balancing

For this task, need to make the resources that help the load balancer work.

Set these values and leave all other settings as default:

Property	Value (type value or select option as specified)
Static external IP	network-lb-ip-1
Target-pool	www-pool
Ports	80

1. Reserve a Static IP

gcloud compute addresses create network-lb-ip-1 \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --region=us-west1

2. Create HTTP Health Check

gcloud compute http-health-checks create basic-check \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --port=80 \
  --request-path=/

3. Create Target Pool

gcloud compute target-pools create www-pool \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --region=us-west1 \
  --http-health-check=basic-check

4. Add Instances to Target Pool

gcloud compute target-pools add-instances www-pool \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --region=us-west1 \
  --instances=web1,web2,web3 \
  --instances-zone=us-west1-b

5. Create Forwarding Rule

gcloud compute forwarding-rules create www-rule \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --region=us-west1 \
  --ports=80 \
  --address=network-lb-ip-1 \
  --target-pool=www-pool

Task 3. Create an HTTP load balancer

For this task, need to make the resources for the HTTP load balancer.

Set the values below and leave all other settings as default:

Property	Value (type value or select option as specified)
Backend Template	lb-backend-template
tags	allow-health-check
Managed instance group	lb-backend-group
machine-type	e2-medium
image-family and image-project	same as previously created VMs
fw-allow-health-check	fw-allow-health-check
Allow source-ranges	130.211.0.0/22, 35.191.0.0/16
Traffic	ingress
Port	80
external IP address	lb-ipv4-1
health check	http-basic-check
URL map	web-map-http
Target http proxy	http-lb-proxy

1. Create Instance Template

gcloud compute instance-templates create lb-backend-template \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --region=us-west1 \
  --network=default \
  --subnet=default \
  --tags=allow-health-check \
  --machine-type=e2-medium \
  --image-family=debian-12 \
  --image-project=debian-cloud \
  --metadata startup-script='#!/bin/bash
apt-get update
apt-get install apache2 -y
a2ensite default-ssl
a2enmod ssl
vm_hostname="$(curl -H "Metadata-Flavor:Google" http://metadata.google.internal/computeMetadata/v1/instance/name)"
echo "Page served from: $vm_hostname" | tee /var/www/html/index.html
systemctl restart apache2'

2. Create Managed Instance Group

gcloud compute instance-groups managed create lb-backend-group \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --zone=us-west1-b \
  --template=lb-backend-template \
  --size=2 \
  --description="Managed instance group for HTTP Load Balancer"

3. Create Firewall Rule for Health Checks

gcloud compute firewall-rules create fw-allow-health-check \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --network=default \
  --action=ALLOW \
  --rules=tcp:80 \
  --source-ranges=130.211.0.0/22,35.191.0.0/16 \
  --target-tags=allow-health-check \
  --description="Allow health check traffic for HTTP Load Balancer"

4. Reserve Global Static IP

gcloud compute addresses create lb-ipv4-1 \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --ip-version=IPV4 \
  --global

5. Create Global HTTP Health Check

gcloud compute health-checks create http http-basic-check \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --port=80 \
  --request-path=/ \
  --global

6. Create Backend Service

gcloud compute backend-services create web-backend-service \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --protocol=HTTP \
  --port-name=http \
  --health-checks=http-basic-check \
  --global \
  --description="Backend service for web servers"

7. Set Named Ports

gcloud compute instance-groups managed set-named-ports lb-backend-group \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --zone=us-west1-b \
  --named-ports=http:80

8. Add Backend to Backend Service

gcloud compute backend-services add-backend web-backend-service \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --instance-group=lb-backend-group \
  --instance-group-zone=us-west1-b \
  --balancing-mode=UTILIZATION \
  --global

9. Create URL Map

gcloud compute url-maps create web-map-http \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --default-service=web-backend-service \
  --global

10. Create HTTP Proxy

gcloud compute target-http-proxies create http-lb-proxy \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --url-map=web-map-http \
  --global

11. Create Global Forwarding Rule

gcloud compute forwarding-rules create http-fwd-rule \
  --project=qwiklabs-gcp-03-8beba1f05a19 \
  --load-balancing-scheme=EXTERNAL \
  --network-tier=PREMIUM \
  --global \
  --target-http-proxy=http-lb-proxy \
  --address=lb-ipv4-1 \
  --ports=80

Conclusion

In this lab, you learned how to build a web server system on Google Cloud Platform (GCP) that can handle more users with load balancing.

You made three web servers and set firewall rules to let web traffic pass. Then you built a Network Load Balancer and an HTTP Load Balancer to share traffic between the servers.

This setup makes your website faster and more stable because the load balancer sends users to servers that are free and working well.

Now you have a simple and strong web server system running on Google Cloud.