Azure function which prints incoming request's headers headers

ip-trace-function.cs

using System.Net;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Primitives;

public static async Task<IActionResult> Run(HttpRequestMessage req, ILogger log){
    var ip = GetIpFromRequestHeaders(req, log);
    log.LogInformation($"IP:[{ip}]");
    return new OkObjectResult(ip);
}

private static string GetIpFromRequestHeaders(HttpRequestMessage request, ILogger log){
  foreach(var header in request.Headers){
    PrintHeader(header.Key, request, log);
  }        
  if (request.Headers.TryGetValues("X-Forwarded-For", out var values)){   
    return values.FirstOrDefault().Split(new char[] { ',' }).FirstOrDefault();
  }
  return string.Empty;
}

private static void PrintHeader(string header, HttpRequestMessage request, ILogger log ){
  if (request.Headers.TryGetValues(header, out var values)){
    foreach(var val in values){
      log.LogInformation($"{header}={val}");
    }
  }
}