WAF support for Web Apps

Question

Here is my scenario:

I have multiple Web Apps (multi-tenant) in an App Service Plan as follows:

custA.azurewebsites.com
custB.azurewebsites.com

Above apps are same except they point to its won tenant DB. So custA talks to DBA, custB talks to custB.

I don't want to create individual custom domains for my customer. Users of CustomerA tenant would access the site using custA.mydomain.com. Users of customerB tenant would access the site using custB.mydomain.com

I would like to use the Application Gateway in front to route the traffic from my customers to their respective websites. Is that possible so that routing happens like this and how

custA.mydomain.com --> custA.azurewebsites.com
custB.mydomain.com --> custB.azurewebsites.com

Thanks

Answer 1

Hello,

Yes, you can implement your scenario using Azure Application Gateway

Rule1 :: Listener1 --> HTTPSettings1 --> BackendPool1

1. Create Listener1 with hostname custA.mydomain.com
2. Leverage the option "Override with specific domain name" in HTTPSettings1 and mention
   "custA.azurewebsites.com" under the same
3. Place the web app custA.azurewebsites.com in a distinct backend pool
4. Configure Rule1 to bind Listener1, HTTPSettings1 and a BackendPool1

Similar configurations needed for custB.mydomain.com

Hope this helps !

Answer 2

Hello @MohitNigam-9331 ,

You may refer to the below articles for more information on how to configure multi-tenant back ends such as App service with Application Gateway:
https://learn.microsoft.com/en-us/azure/application-gateway/application-gateway-web-app-overview
https://learn.microsoft.com/en-us/azure/application-gateway/configure-web-app-portal

In your scenario, you can make use of multi-site listeners and create 2 listeners with respective hostnames - custA.mydomain.com & custB.mydomain.com.
Add App service as backend pool.
Create HTTP settings for App service.
Make use of Override host header in the request in your HTTP settings.
Create Rule to tie the Listener, Backend Pool and HTTP Setting.

For information on Troubleshooting App Service issues in Application Gateway, please refer:
https://learn.microsoft.com/en-us/azure/application-gateway/troubleshoot-app-service-redirection-app-service-url

Kindly let us know if the above helps or you need further assistance on this issue.

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