一、目的

通过用户接口获取其真实的ip地址，最终获取到用户所在国家。

针对情况包括：

1、ssr node端请求后端接口 获取ip

2、客户端请求后端接口 获取ip

二、问题

目前通过接口获取不到外网ip而是内网ip

原因：

• 接口是nuxt的ssr服务器端渲染接口，而非普通客户端请求接口（原理为从node服务器端，发起的请求，其ip必定为咱们服务器的内网ip地址）

三、方案

主要是依赖于nginx，获取其真实ip

1、nginx 转发到node服务的location中， header里面设置 x-real-ip 为 $remote_addr X-Forwarded-For 设为 $proxy_add_x_forwarded_for;

 location / {                                                                                               
                 proxy_pass   http://10.10.50.191:88;                                                      
                proxy_set_header Host  $host;
                # need set x-real-ip and x-forwarded-for to get user ip 
                proxy_set_header X-Real-Ip $remote_addr;
                 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

  # nginx代理接口
  location ^~ /baseUrl/ {                                                                                                                                                 
      proxy_pass   http://域名:19000/;                                                                                                                          
      proxy_cookie_path /baseUrl/ /;                                                                                                                                     
      proxy_pass_header Set-Cookie;             
      proxy_set_header Host  $host;
      proxy_set_header X-Real-Ip $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }

2、前端 从 服务器端渲染代码处， async nuxtServerInit (或者async asyncData） 里面获取 req

3、req里面会有 nginx设置进去的header，x-real-ip x-forwarded-for，值为ip地址

4、把它重新设置到axios的header中

5、后端从接口header里面就可以拿到一开始设置的remote_addr了

以上方案针对于 服务器渲染请求的接口，后端从接口中获取其用户的真实ip的情况。主要是依赖前端（req中获取header，重新设入）、nginx、后端配合实现。

对于普通的客户端请求接口，后端从接口中获取其用户的真实ip的情况，也是同样适用。主要是依赖nginx的代理转发，设置header，后端直接获取就可以实现。

获取ip对应的国家（后端逻辑）

后端有ip数据表，里面有很多国家的ip地址，通过查表来获取对应国家简码，如US、CN

ssr服务端接口请求获取国家（通过ip）整个逻辑

客户端请求获取国家整个逻辑

参考代码

nginx配置

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for" - $http_x_real_ip - $proxy_add_x_forwarded_for';

    access_log  /var/log/nginx/access.log  main;

   client_max_body_size   200m;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;
    
    server {
       listen      80;
            server_name  localhost;

            #charset koi8-r;

            #access_log  logs/host.access.log  main;

			# nginx转发到node
             location / {
                 proxy_pass   http://10.10.50.97:88;
                 proxy_set_header Host  $host;
                # need set x-real-ip and x-forwarded-for to get user ip 
                proxy_set_header X-Real-Ip $remote_addr;
                 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
          
         }

            #error_page  404              /404.html;

            # redirect server error pages to the static page /50x.html
            #
            error_page   500 502 503 504  /50x.html;
            location = /50x.html {
                root   html;
            }  
            
             # nginx代理接口
            location ^~ /baseUrl/ {                                                                                                                                                 
                proxy_pass   http://域名:19000/;                                                                                                                          
                proxy_cookie_path /baseUrl/ /;                                                                                                                                     
                proxy_pass_header Set-Cookie;             
                proxy_set_header Host  $host;
                proxy_set_header X-Real-Ip $remote_addr;
                 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            }
   }
            
   include /etc/nginx/conf.d/*.conf;
}

java

public final class NetUtils {
    private NetUtils() {
    }

    public static String getRealIp(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
            if ("127.0.1".equals(ip) || "0:0:0:0:0:0:0:1".equals(ip)) {
                InetAddress address = (InetAddress)Safe.call(InetAddress::getLocalHost);
                ip = address.getHostAddress();
            }
        }

        if (ip != null && ip.length() > 15) {
            int i = ip.indexOf(",");
            if (i > 0) {
                ip = ip.substring(0, i);
            }
        }

        return ip;
    }
}