Azure App Services Header - X-Forwarded-For - Rewrite

Question

Hello everyone

Currently I have an App Service running a Docker Container and an Application Gateway because I need to customize the header X-Forwarded-For. Here you can find the current rules I have created:

But since the Application Gateway is relatively expensive and I only need it because of this rule, I was wondering if there is another way to do this directly in the App Service or if there is another cheaper way to do this.

Best regards

Adrian

Answer 1

Thanks for posting your question in the Microsoft Q&A forum.

There are a few alternative approaches you can consider that may be more cost-effective than using an Application Gateway:

1. Azure Front Door Service: Azure Front Door is a global load balancer and application delivery network service that can act as a reverse proxy for your App Service. it supports rewriting the X-Forwarded-For header by using the X-Forwarded-For rule engine. while not as feature-rich as Application Gateway, Azure Front Door may be a more cost-effective option for your specific use case of rewriting the X-Forwarded-For header.
2. Azure API Management: Azure API Management is a service that can act as a reverse proxy for your App Service. it allows you to modify request and response headers through policies, including the X-Forwarded-For header. you can create a policy to set the X-Forwarded-For header to the desired value, such as the add_x_forwarded_for_proxy server variable.
3. Azure Functions Proxy: You can create an Azure Function that acts as a proxy for your App Service. within the Azure Function, you can modify the X-Forwarded-For header before forwarding the request to your App Service. this approach requires some additional development effort but can be a cost-effective solution if you already have Azure Functions in your architecture.

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