Getting Client-IP from Azure Functions - .NET Isolated

Question

I have seen many solutions of getting client IP address which are from Azure Functions .Net 3.1, 6, JavaScript, etc.

Our Project belongs to .NET Core 6 Isolated Version. So, can you help me how to get the Client-IP using HttpRequestData class present in HttpTrigger .Net 6 Isolated Azure Function?

I have tried the following code snippets to get, but unfortunately failed:

1. var remoteAddress = req.HttpContext.Connection.RemoteIpAddress;

To try this line, I'm not getting the HttpContext object of request.

2. Few Code snippets present in this SO Reference are not working in .NET 6 Isolated.
3. Found another SO Reference which given me the code snippet of .NET 5 Isolated, but that doesn't worked for me in the same version of .NET 5 isolated also.

Answer 1

Checking the request.Headers["X-Forwarded-For"] parameter should work when the function app is published on Azure (not locally).

Answer 2

@NFSCoder-9821 ,

If you are willing to integrate an APIM in front of Azure function, then the Client IP can be passed along to the Function App by way of defining a header via a small policy snippet:

<set-header name="X-Forwarded-Client-Ip" exists-action="override">
<value>@(context.Request.IpAddress)</value>
</set-header>

APIM maintains Client IP through context variable as follows: context.Request.IpAddress

The corresponding value then can be accessed in your HttpTrigger function via HttpRequest object as follows:

public static async Task<IActionResult> Run(HttpRequest req, ILogger log)
{
....

var clientIP = req.Headers["X-Forwarded-Client-Ip"];  
....  

}

This way you can get the client ip of the function app