دریافت IP واقعی کاربر در زمان استفاده از Reverse Proxy در Nginx

server {
     location /api {
        rewrite ^/api/(.*)$ /$1 break;
        proxy_pass http://server.op.local:9090;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
     }
}

namespace MyCode
{
    public class CustomActionFilterAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(HttpActionContext context)
        {
            var ip = GetClientIp(context.Request);

            base.OnActionExecuting(context);
        }

        private string GetClientIp(HttpRequestMessage request)
        {
            try
            {
                var isSuccess = request.Headers.TryGetValues("X-Forwarded-For", out var items);

                if (isSuccess)
                {
                    return items.FirstOrDefault();
                }

                if (request.Properties.ContainsKey("MS_HttpContext"))
                {
                    return ((HttpContextWrapper)request.Properties["MS_HttpContext"]).Request.UserHostAddress;
                }

                if (request.Properties.ContainsKey(RemoteEndpointMessageProperty.Name))
                {
                    var prop = (RemoteEndpointMessageProperty)request.Properties[RemoteEndpointMessageProperty.Name];
                    return prop.Address;
                }

                return "Unknown";
            }
            catch (Exception)
            {
                return "CanNotFound";
            }
        }
    }
}