将所有的witk @kakopappa解决方案加上morgan客户端ip地址的日志记录:

morgan.token('client_ip', function getId(req) {
    return req.client_ip
});
const LOG_OUT = ':remote-addr - :remote-user [:date[clf]] ":method :url HTTP/:http-version" :status :res[content-length] ":referrer" ":user-agent" :client_ip'
self.app.use(morgan(LOG_OUT, {
    skip: function(req, res) { // custom logging: filter status codes
        return res.statusCode < self._options.logging.statusCode;
    }
}));

// could-flare, nginx and x-real-ip support
var getIpInfoMiddleware = function(req, res, next) {
    var client_ip;
    if (req.headers['cf-connecting-ip'] && req.headers['cf-connecting-ip'].split(', ').length) {
        var first = req.headers['cf-connecting-ip'].split(', ');
        client_ip = first[0];
    } else {
        client_ip = req.headers['x-forwarded-for'] || req.headers['x-real-ip'] || req.connection.remoteAddress || req.socket.remoteAddress || req.connection.socket.remoteAddress;
    }
    req.client_ip = client_ip;
    next();
};
self.app.use(getIpInfoMiddleware);

虽然来自@alessioalex的答案是有效的，但在Express - guide的Express后台代理部分中有另一种方法。

在初始化代码中添加app.set('trust proxy'， true)。 当您想要获取远程客户端的ip时，使用req。IP或req。以通常的方式进行Ips(就好像没有反向代理一样)

可选的阅读:

Use req.ip or req.ips. req.connection.remoteAddress does't work with this solution. More options for 'trust proxy' are available if you need something more sophisticated than trusting everything passed through in x-forwarded-for header (for example, when your proxy doesn't remove preexisting x-forwarded-for header from untrusted sources). See the linked guide for more details. If your proxy server does not populated x-forwarded-for header, there are two possibilities. The proxy server does not relay the information on where the request was originally. In this case, there would be no way to find out where the request was originally from. You need to modify configuration of the proxy server first. For example, if you use nginx as your reverse proxy, you may need to add proxy_set_header X-Forwarded-For $remote_addr; to your configuration. The proxy server relays the information on where the request was originally from in a proprietary fashion (for example, custom http header). In such case, this answer would not work. There may be a custom way to get that information out, but you need to first understand the mechanism.

与could-flare, nginx和x-real-ip支持

var user_ip;

    if(req.headers['cf-connecting-ip'] && req.headers['cf-connecting-ip'].split(', ').length) {
      let first = req.headers['cf-connecting-ip'].split(', ');
      user_ip = first[0];
    } else {
      let user_ip = req.headers['x-forwarded-for'] || req.headers['x-real-ip'] || req.connection.remoteAddress || req.socket.remoteAddress || req.connection.socket.remoteAddress;
    }

如果你在运行一个像NGiNX之类的代理，那么你应该检查'x-forward -for':

var ip = req.headers['x-forwarded-for'] || req.socket.remoteAddress 

如果代理不是“你的”，我不会相信“x-forward -for”报头，因为它可能被欺骗。

这只是这个答案的附加信息。

如果你正在使用nginx，你需要添加proxy_set_header X-Real-IP $remote_addr;到站点的位置块。例如:/etc/nginx/sites-available/www.example.com。下面是一个服务器块示例。

server {
    listen 80;
    listen [::]:80;

    server_name example.com www.example.com;

    location / {
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_pass http://127.0.1.1:3080;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

重新启动nginx后，你将能够使用req访问你的节点/express应用程序路由中的ip。headers['x-real-ip'] || req.connection.remoteAddress;

我知道这个问题已经有了答案，但下面是我如何让我的问题起作用的。

let ip = req.connection.remoteAddress.split(`:`).pop();