你可以保持DRY，只使用支持IPv4和IPv6的node-ipware。

安装:

npm install ipware

在你的app.js或中间件中:

var getIP = require('ipware')().get_ip;
app.use(function(req, res, next) {
    var ipInfo = getIP(req);
    console.log(ipInfo);
    // { clientIp: '127.0.0.1', clientIpRoutable: false }
    next();
});

它将尽最大努力获取用户的IP地址或返回127.0.0.1，以表明它无法确定用户的IP地址。查看README文件中的高级选项。

在Typescript中使用ValidatorJS。下面是NodeJS中间件:

// Extract Client IP Address
app.use((req, res, next) => {
    let ipAddress = (req.headers['x-forwarded-for'] as string || '').split(',')[0]
    if (!validator.isIP(ipAddress))
        ipAddress = req.socket.remoteAddress?.toString().split(':').pop() || ''
    if (!validator.isIP(ipAddress))
        return res.status(400).json({errorMessage: 'Bad Request'})

    req.headers['x-forwarded-for'] = ipAddress
    next()
})

在这里，我假设所有请求都应该有一个有效的IP地址，因此如果没有找到有效的IP地址，则返回一个代码为400的响应。

请求。headers['x-forwarded-for'] || request.connection.remoteAddress . headers['x-forwarded-for'

如果有x-forward -for报头，则使用它，否则使用. remoteaddress属性。

The x-forwarded-for header is added to requests that pass through load balancers (or other types of proxy) set up for HTTP or HTTPS (it's also possible to add this header to requests when balancing at a TCP level using proxy protocol). This is because the request.connection.remoteAddress the property will contain the private IP address of the load balancer rather than the public IP address of the client. By using an OR statement, in the order above, you check for the existence of an x-forwarded-for header and use it if it exists otherwise use the request.connection.remoteAddress.

你可以使用request-ip来获取用户的ip地址。它处理了很多不同的边界情况，其中一些在其他答案中提到过。

披露:我创建了这个模块

安装:

npm install request-ip

在你的应用中:

var requestIp = require('request-ip');

// inside middleware handler
var ipMiddleware = function(req, res, next) {
    var clientIp = requestIp.getClientIp(req); // on localhost > 127.0.0.1
    next();
};

希望这能有所帮助

这里有很多很棒的观点，但没有一个是全面的，所以这里是我最终使用的:

function getIP(req) {
  // req.connection is deprecated
  const conRemoteAddress = req.connection?.remoteAddress
  // req.socket is said to replace req.connection
  const sockRemoteAddress = req.socket?.remoteAddress
  // some platforms use x-real-ip
  const xRealIP = req.headers['x-real-ip']
  // most proxies use x-forwarded-for
  const xForwardedForIP = (() => {
    const xForwardedFor = req.headers['x-forwarded-for']
    if (xForwardedFor) {
      // The x-forwarded-for header can contain a comma-separated list of
      // IP's. Further, some are comma separated with spaces, so whitespace is trimmed.
      const ips = xForwardedFor.split(',').map(ip => ip.trim())
      return ips[0]
    }
  })()
  // prefer x-forwarded-for and fallback to the others
  return xForwardedForIP || xRealIP || sockRemoteAddress || conRemoteAddress
}

以下函数涵盖了所有的情况，将会有所帮助

var ip;
if (req.headers['x-forwarded-for']) {
    ip = req.headers['x-forwarded-for'].split(",")[0];
} else if (req.connection && req.connection.remoteAddress) {
    ip = req.connection.remoteAddress;
} else {
    ip = req.ip;
}console.log("client IP is *********************" + ip);