K8S POD如何获取客户端IP

• 问题：
  在K8S上部署应用时候，会发现从POD里边获取的IP一直都是F5的IP，思虑良久，怀疑是Ingres端那边被丢弃了类似X-FORWARD-FOR的信息，于是就有了下面的解决方案。
• 解决方案：
  Rancher上配置界面如下，在项目：System，命名空间ingress-nginx，配置映射： nginx-configuration中增加键值对即可。
  • 参数说明：
    （1）compute-full-forwarded-for
    Append the remote address to the X-Forwarded-For header instead of replacing it. When this option is enabled, the upstream application is responsible for extracting the client IP based on its own list of trusted proxies.
    （2）forwarded-for-header
    Sets the header field for identifying the originating IP address of a client. default: X-Forwarded-For
    （3）use-forwarded-headers
• If true, NGINX passes the incoming X-Forwarded-* hea