负载均衡器就位时获取真实客户端IP地址问题

Question

https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/proxy-load-balancer?view=aspnetcore-3.0&viewFallbackFrom=aspnetcore-1.1#forwarded-headers-middleware-options 

这是用于实现的文章

示例代码

1)使用转发选项配置服务

  public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddApplicationInsightsTelemetry(Configuration);
            services.Configure<AppSettings>(Configuration);
            services.AddMvc();
            services.Configure<ForwardedHeadersOptions>(options =>
            {
                options.ForwardedHeaders =
                    ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
                options.ForwardLimit = 2;
                options.KnownProxies.Add(System.Net.IPAddress.Parse("123.111.11.88"));
                //options.KnownProxies.Clear();
                //options.KnownNetworks.Clear();
            });
        }

2)配置方法变更如下：

  public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
           --------
            app.UseForwardedHeaders();
           -------
      }

3)读取headers的代码如下：

 string realClientIP = GetHeaderValueAs<string>("X-Cluster-Client-Ip");

 public T GetHeaderValueAs<T>(string headerName)
        {
            StringValues values;

            Request.Headers.TryGetValue(headerName, out values);
            if (!StringValues.IsNullOrEmpty(values))
            {
                var rawValues = values.ToString();

                if (!string.IsNullOrEmpty(rawValues))
                    return (T)Convert.ChangeType(values.ToString(), typeof(T));
            }

            return default(T);
        }

查询：

1)这是获得. net core 1.1真实客户端IP的正确方法吗?因为我可以看到MSDN文章是针对. net core 3.0的，而没有关于core 1.0的参考文章。

2)是否可以使用自定义头部获取结果?如果可能，如何获取结果？

3)有没有其他办法请告诉我？

Answer 1

步骤1。将代码更改为

 services.Configure<ForwardedHeadersOptions>(options =>
        {
            options.ForwardedHeaders =
                ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
  
              options.KnownProxies.Clear();
             options.KnownNetworks.Clear();
        });

步骤2。添加ContextAccessor

 services.AddHttpContextAccessor();
        services.TryAddSingleton<IActionContextAccessor, ActionContextAccessor>();

步骤3。使用IActionContextAccessor获取IP，如下所示

public static string GetClientIp(this IActionContextAccessor contextAccessor)
    {
        var remoteIp = contextAccessor.ActionContext.HttpContext.Connection.RemoteIpAddress;

        if (remoteIp.IsIPv4MappedToIPv6)
        {
            remoteIp = remoteIp.MapToIPv4();
        }

        return remoteIp.ToString();
    }