How to Implement Azure Application Gateway for a Secure and Scalable E-Commerce Platform

Azure Application Gateway for E-commerce Platform with Global Traffic

Challenge:

A large e-commerce platform needs to handle high volumes of web traffic from various regions worldwide. The platform requires a solution to:

1. Distribute traffic effectively across multiple web servers.
2. Secure sensitive customer data by encrypting communications.
3. Optimize performance through intelligent routing.
4. Manage sudden traffic spikes during sales events.
5. Protect against common web vulnerabilities like SQL injection and cross-site scripting.

Solution: Azure Application Gateway

1. Load Balancing: Application Gateway provides layer 7 load balancing, distributing traffic based on HTTP requests, ensuring even load distribution across the web servers.
2. SSL Offloading: It offloads SSL termination, encrypting traffic at the gateway and reducing the load on web servers.
3. Autoscaling: During high-traffic events (e.g., flash sales), Application Gateway’s autoscaling adjusts capacity based on demand, avoiding downtime.
4. Web Application Firewall (WAF): The built-in WAF in the Application Gateway protects the e-commerce platform against OWASP top 10 threats and other web vulnerabilities.
5. Path-Based Routing: Using URL-based routing, traffic is routed to the appropriate backend pools. For example, requests for /product-images are directed to image servers, and /checkout requests are sent to secure payment servers.
6. Global Reach: For a global audience, Application Gateway integrates with Azure Front Door to offer low-latency experiences by routing users to the nearest Azure region.

Outcome:

The e-commerce platform achieves:

Improved security, protecting customer data and transactions.

Higher availability through autoscaling and efficient load distribution.

Enhanced performance by routing traffic intelligently and offloading SSL processing.

This allows the business to focus on growth and customer experience, knowing the infrastructure can scale and secure traffic globally.

To implement Azure Application Gateway for the global e-commerce platform, follow these steps:

Prerequisites

Azure Subscription: Ensure you have an active Azure subscription.

Backend Pools: Prepare multiple backend web servers (e.g., VMs, App Services, or Kubernetes) to host your application.

SSL Certificates: Obtain a valid SSL certificate for secure communication.

Custom Domain: Set up a custom domain (e.g., www.yourstore.com) for the e-commerce platform.

Step-by-Step Implementation

1. Create a Virtual Network (VNet)

Application Gateway requires a virtual network to operate. This VNet will include subnets for the Application Gateway and the backend servers.

Go to Azure Portal > Create a resource > Virtual Network.

Configure the IP address range (e.g., 10.0.0.0/16).

Create two subnets within the VNet:AppGatewaySubnet: For Application Gateway.BackendSubnet: For backend servers hosting the web application.

2. Create Backend Resources

Ensure that your backend servers (VMs, App Services, or other resources) are deployed within the BackendSubnet of the VNet. These resources will handle incoming traffic from Application Gateway.

Deploy necessary VMs or App Services.

Ensure all services are up and running.

3. Create an Application Gateway

Now, set up the Application Gateway that will route and secure traffic.

Go to Azure Portal > Create a resource > Networking > Application Gateway.

Choose the subscription, resource group, and location.

Under Configuration, set the following:

Under Frontend ports: Define ports such as 443 for HTTPS traffic.

4. Configure SSL (HTTPS)

To ensure secure communication:

Upload your SSL certificate to Azure in PFX format during the Application Gateway setup.In the HTTP settings, select HTTPS and attach the SSL certificate.Enable SSL termination to offload SSL decryption to the Application Gateway.

5. Set Up Backend Pools

Backend pools are the collection of servers that the Application Gateway will route traffic to.

Under Backend Pools, add your e-commerce platform’s web servers (VMs or App Services) as members.

Define the health probe to check the health of the backend servers (e.g., probing a /health endpoint).

6. Configure Path-Based Routing

For better traffic distribution, you can configure path-based routing.

In the Routing Rules section, add a rule for path-based routing.Example:/checkout → Routes to payment backend pool./product-images → Routes to a static content server pool.

This helps distribute traffic effectively to different backend resources.

7. Enable Web Application Firewall (WAF)

To protect your platform against common web vulnerabilities like SQL injection, cross-site scripting, etc., configure the Web Application Firewall (WAF):

In the Firewall section, select WAF_v2 during setup.

Configure OWASP rule set to protect against the most common security threats.

Enable custom rules if you have specific security requirements.

8. Test the Application Gateway

After deployment, test the Application Gateway by sending traffic through it to ensure:

The SSL offloading is working correctly (traffic over HTTPS).

Traffic is routed to the appropriate backend pools.

WAF is protecting the application against potential threats.

9. Integrate with Azure Front Door (Optional)

To further optimize global traffic delivery, you can integrate Azure Front Door with Application Gateway:

Azure Front Door will act as a global entry point for your application, routing users to the closest Azure region.

It can work alongside Application Gateway to optimize latency and improve global user experience.

10. Monitor and Maintain

Use Azure Monitor and Application Insights to track traffic patterns, backend health, and security alerts. Set up alerts for traffic spikes or security incidents detected by WAF.

Example ARM Template for Quick Deployment

If you prefer using an ARM template for faster deployment:

{
??"$schema":?"https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
??"contentVersion":?"1.0.0.0",
??"resources":?[
????{
??????"type":?"Microsoft.Network/applicationGateways",
??????"apiVersion":?"2020-06-01",
??????"name":?"myAppGateway",
??????"location":?"[resourceGroup().location]",
??????"properties":?{
????????"sku":?{
??????????"name":?"WAF_v2",
??????????"tier":?"WAF_v2",
??????????"capacity":?2
????????},
????????"gatewayIPConfigurations":?[
??????????{
????????????"name":?"appGatewayIpConfig",
????????????"properties":?{
??????????????"subnet":?{
????????????????"id":?"[resourceId('Microsoft.Network/virtualNetworks/subnets',?'myVNet',?'appGatewaySubnet')]"
??????????????}
????????????}
??????????}
????????],
????????"frontendIPConfigurations":?[
??????????{
????????????"name":?"appGatewayFrontendIp",
????????????"properties":?{
??????????????"publicIPAddress":?{
????????????????"id":?"[resourceId('Microsoft.Network/publicIPAddresses',?'myPublicIP')]"
??????????????}
????????????}
??????????}
????????],
????????"frontendPorts":?[
??????????{
????????????"name":?"httpsPort",
????????????"properties":?{
??????????????"port":?443
????????????}
??????????}
????????],
????????"sslCertificates":?[
??????????{
????????????"name":?"mySslCert",
????????????"properties":?{
??????????????"data":?"[parameters('sslCertData')]",
??????????????"password":?"[parameters('sslCertPassword')]"
????????????}
??????????}
????????],
????????"backendAddressPools":?[
??????????{
????????????"name":?"myBackendPool",
????????????"properties":?{
??????????????"backendAddresses":?[
????????????????{
??????????????????"ipAddress":?"10.0.1.4"
????????????????},
????????????????{
??????????????????"ipAddress":?"10.0.1.5"
????????????????}
??????????????]
????????????}
??????????}
????????],
????????"httpSettingsCollection":?[
??????????{
????????????"name":?"httpsSetting",
????????????"properties":?{
??????????????"port":?443,
??????????????"protocol":?"Https",
??????????????"cookieBasedAffinity":?"Disabled",
??????????????"pickHostNameFromBackendAddress":?false,
??????????????"probeEnabled":?true,
??????????????"sslCertificate":?{
????????????????"id":?"[concat(resourceId('Microsoft.Network/applicationGateways',?'myAppGateway'),?'/sslCertificates/mySslCert')]"
??????????????}
????????????}
??????????}
????????],
????????"urlPathMaps":?[
??????????{
????????????"name":?"urlPathMap",
????????????"properties":?{
??????????????"defaultBackendAddressPool":?{
????????????????"id":?"[concat(resourceId('Microsoft.Network/applicationGateways',?'myAppGateway'),?'/backendAddressPools/myBackendPool')]"
??????????????},
??????????????"defaultBackendHttpSettings":?{
????????????????"id":?"[concat(resourceId('Microsoft.Network/applicationGateways',?'myAppGateway'),?'/httpSettingsCollection/httpsSetting')]"
??????????????},
??????????????"pathRules":?[
????????????????{
??????????????????"name":?"checkoutRule",
??????????????????"properties":?{
????????????????????"paths":?[
??????????????????????"/checkout/*"
????????????????????],
????????????????????"backendAddressPool":?{
??????????????????????"id":?"[concat(resourceId('Microsoft.Network/applicationGateways',?'myAppGateway'),?'/backendAddressPools/checkoutBackendPool')]"
????????????????????}
??????????????????}
????????????????}
??????????????]
????????????}
??????????}
????????]
??????}
????}
??]
}        

This deployment includes SSL, autoscaling, path-based routing, and WAF integration. You can customize IP addresses and backend pools as per your setup.