nginx做反向负载均衡，后端服务器获取真实客户端ip

nginx增加header配置

server {
    listen       80;
    server_name  admin.paascloud.net;
    location ~ {

        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header REMOTE-HOST $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        ...
    }
}

后端获取客户端ip代码

public static String getRemoteAddr(HttpServletRequest request) {
        String ipAddress = request.getHeader(GlobalConstant.X_Real_IP);
        if (StringUtils.isEmpty(ipAddress) || GlobalConstant.UNKNOWN.equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader(GlobalConstant.X_FORWARDED_FOR);
            log.info("X_FORWARDED_FOR ip: ", ipAddress);
        }
        if (StringUtils.isEmpty(ipAddress) || GlobalConstant.UNKNOWN.equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader(GlobalConstant.PROXY_CLIENT_IP);
            log.info("PROXY_CLIENT_IP ip: ", ipAddress);
        }
        if (StringUtils.isEmpty(ipAddress) || GlobalConstant.UNKNOWN.equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader(GlobalConstant.WL_PROXY_CLIENT_IP);
            log.info("WL_PROXY_CLIENT_IP ip: ", ipAddress);
        }
        if (StringUtils.isEmpty(ipAddress) || GlobalConstant.UNKNOWN.equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader(GlobalConstant.HTTP_CLIENT_IP);
            log.info("HTTP_CLIENT_IP ip: ", ipAddress);
        }
        if (StringUtils.isEmpty(ipAddress) || GlobalConstant.UNKNOWN.equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader(GlobalConstant.HTTP_X_FORWARDED_FOR);
            log.info("HTTP_X_FORWARDED_FOR ip: ", ipAddress);
        }
        if (StringUtils.isEmpty(ipAddress) || GlobalConstant.UNKNOWN.equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getRemoteAddr();
            log.info("getRemoteAddr ip: ", ipAddress);
        }
        if (StringUtils.isEmpty(ipAddress) || GlobalConstant.UNKNOWN.equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getRemoteAddr();
            if (GlobalConstant.LOCALHOST_IP.equals(ipAddress) || GlobalConstant.LOCALHOST_IP_16.equals(ipAddress)) {
                //根据网卡取本机配置的IP
                InetAddress inet = null;
                try {
                    inet = InetAddress.getLocalHost();
                } catch (UnknownHostException e) {
                    logger.error("获取IP地址, 出现异常={}", e.getMessage(), e);
                }
                assert inet != null;
                ipAddress = inet.getHostAddress();
            }
            log.info("获取IP地址 ipAddress={}", ipAddress);
        }
        // 对于通过多个代理的情况, 第一个IP为客户端真实IP,多个IP按照','分割 //"***.***.***.***".length() = 15
        if (ipAddress != null && ipAddress.length() > GlobalConstant.MAX_IP_LENGTH) {
            if (ipAddress.indexOf(GlobalConstant.Symbol.COMMA) > 0) {
                ipAddress = ipAddress.substring(0, ipAddress.indexOf(GlobalConstant.Symbol.COMMA));
            }
        }
        return ipAddress;
    }

springboot 增加配置

server:
  tomcat:
    uri-encoding: UTF-8
    remote-ip-header: x-forwarded-for
  use-forward-headers: true
  ...