代码实例：

package main

import (
    "net"
    "net/http"
    "strings"
)

func GetIP(w http.ResponseWriter, r *http.Request) {
    // 尝试从 X-Forwarded-For 中获取
    xForwardedFor := r.Header.Get(`X-Forwarded-For`)
    ip := strings.TrimSpace(strings.Split(xForwardedFor, `,`)[0])
    if ip == `` {
        // 尝试从 X-Real-Ip 中获取
        ip = strings.TrimSpace(r.Header.Get(`X-Real-Ip`))
        if ip == `` {
            // 直接从 Remote Addr 中获取
            _ip, _, err := net.SplitHostPort(strings.TrimSpace(r.RemoteAddr))
            if err != nil {
                panic(err)
            } else {
                ip = _ip
            }
        }
    }
    // 从控制台输出获取到的IP地址
    println(ip)
}

func main() {
    http.HandleFunc(`/`, GetIP)
    err := http.ListenAndServe(`:80`, nil)
    if err != nil {
        panic(err)
    }
}