How do I extract an ip address in the azure api management policy? - policy

Question

Is there an out of the box policy to extract the incoming ip address? I could not find one.
Do I need to write code to do that? If so, how do I go about it? What are the other alternatives?

Answer 1

You can extract IP address in any policies using policy expressions. The expression would be context.Request.IpAddress

Answer 2

You can definitely use policy expressions.
But an easier approach might be the below:
If your goal is to capture the origin IP address (and not Azure's) on your backend (for logging purposes, etc.), then:
Whenever Azure API Management Studio forwards requests to your backend, it includes the header X-Forwarded-For
E.g.
{[X-Forwarded-For, 123.45.67.891, 13.75.131.25:1795]}
The first IP Address is the one you want.
The second IP Address is actually Azure's.
E.g. First, A mobile app makes a request to Azure API Mgmt --> Second, Azure API Mgmt forwards the request to your back end --> Lastly, you capture client's the IP (i.e. the mobile device's IP) from X-Forwarded-For.
How you capture the IP from the headers on your backend is up to you and what technology you're using (e.g. ASP.net core, node.js, etc.).
Here's a snippet of code where I'm capturing the IP
private LogMetadata BuildRequestMetadata(HttpRequestMessage request, Task<string> requestBody)
{
var headers = request.Headers.ToDictionary(d => d.Key, d => d.Value.Join(", "));
// If header X-Forwarded-For is included,
// it means the request is coming from Azure API MGMT studio.
// Example header value: {[X-Forwarded-For, 123.45.67.891 (Mobile Device), 13.75.131.25:1795 (Azure API Mgmt)]}
var clientIp =
headers.ContainsKey("X-Forwarded-For")
? headers["X-Forwarded-For"].Split(',')[0]
: request.GetOwinContext().Request.RemoteIpAddress;
}