更大的问题是“为什么?”

如果你需要知道Node.js实例监听的服务器，你可以使用req.hostname。

谷歌在搜索“Node.js获取服务器IP”时引导我到这个问题，所以让我们为那些试图在他们的Node.js服务器程序中实现这一点的人提供一个替代答案(可能是原始海报的情况)。

在最简单的情况下，服务器只绑定到一个IP地址，应该不需要确定IP地址，因为我们已经知道将它绑定到哪个地址(例如，传递给listen()函数的第二个参数)。

在不太简单的情况下，服务器绑定到多个IP地址，我们可能需要确定客户端连接到的接口的IP地址。正如Tor Valamo所简单建议的，现在，我们可以很容易地从连接的套接字及其localAddress属性中获得这些信息。

例如，如果程序是web服务器:

var http = require("http")

http.createServer(function (req, res) {
    console.log(req.socket.localAddress)
    res.end(req.socket.localAddress)
}).listen(8000)

如果它是一个通用TCP服务器:

var net = require("net")

net.createServer(function (socket) {
    console.log(socket.localAddress)
    socket.end(socket.localAddress)
}).listen(8000)

在运行服务器程序时，该解决方案提供了非常高的可移植性、准确性和效率。

详情请参见:

http://nodejs.org/api/net.html http://nodejs.org/api/http.html

下面是我获取本地IP地址的实用方法，假设您正在寻找一个IPv4地址，而机器只有一个真实的网络接口。可以很容易地对其进行重构，以返回多接口机器的IP地址数组。

function getIPAddress() {
  var interfaces = require('os').networkInterfaces();
  for (var devName in interfaces) {
    var iface = interfaces[devName];

    for (var i = 0; i < iface.length; i++) {
      var alias = iface[i];
      if (alias.family === 'IPv4' && alias.address !== '127.0.0.1' && !alias.internal)
        return alias.address;
    }
  }
  return '0.0.0.0';
}

对于Underscore.js和Lodash，正确的一行代码是:

var ip = require('underscore')
    .chain(require('os').networkInterfaces())
    .values()
    .flatten()
    .find({family: 'IPv4', internal: false})
    .value()
    .address;

下面的解决方案对我来说是可行的

const ip = Object.values(require("os").networkInterfaces())
        .flat()
        .filter((item) => !item.internal && item.family === "IPv4")
        .find(Boolean).address;

这是我的变体，允许以可移植的方式获得IPv4和IPv6地址:

/**
 * Collects information about the local IPv4/IPv6 addresses of
 * every network interface on the local computer.
 * Returns an object with the network interface name as the first-level key and
 * "IPv4" or "IPv6" as the second-level key.
 * For example you can use getLocalIPs().eth0.IPv6 to get the IPv6 address
 * (as string) of eth0
 */
getLocalIPs = function () {
    var addrInfo, ifaceDetails, _len;
    var localIPInfo = {};
    //Get the network interfaces
    var networkInterfaces = require('os').networkInterfaces();
    //Iterate over the network interfaces
    for (var ifaceName in networkInterfaces) {
        ifaceDetails = networkInterfaces[ifaceName];
        //Iterate over all interface details
        for (var _i = 0, _len = ifaceDetails.length; _i < _len; _i++) {
            addrInfo = ifaceDetails[_i];
            if (addrInfo.family === 'IPv4') {
                //Extract the IPv4 address
                if (!localIPInfo[ifaceName]) {
                    localIPInfo[ifaceName] = {};
                }
                localIPInfo[ifaceName].IPv4 = addrInfo.address;
            } else if (addrInfo.family === 'IPv6') {
                //Extract the IPv6 address
                if (!localIPInfo[ifaceName]) {
                    localIPInfo[ifaceName] = {};
                }
                localIPInfo[ifaceName].IPv6 = addrInfo.address;
            }
        }
    }
    return localIPInfo;
};

下面是同一个函数的CoffeeScript版本:

getLocalIPs = () =>
    ###
    Collects information about the local IPv4/IPv6 addresses of
      every network interface on the local computer.
    Returns an object with the network interface name as the first-level key and
      "IPv4" or "IPv6" as the second-level key.
    For example you can use getLocalIPs().eth0.IPv6 to get the IPv6 address
      (as string) of eth0
    ###
    networkInterfaces = require('os').networkInterfaces();
    localIPInfo = {}
    for ifaceName, ifaceDetails of networkInterfaces
        for addrInfo in ifaceDetails
            if addrInfo.family=='IPv4'
                if !localIPInfo[ifaceName]
                    localIPInfo[ifaceName] = {}
                localIPInfo[ifaceName].IPv4 = addrInfo.address
            else if addrInfo.family=='IPv6'
                if !localIPInfo[ifaceName]
                    localIPInfo[ifaceName] = {}
                localIPInfo[ifaceName].IPv6 = addrInfo.address
    return localIPInfo

console.log(getLocalIPs())的示例输出

{ lo: { IPv4: '127.0.0.1', IPv6: '::1' },
  wlan0: { IPv4: '192.168.178.21', IPv6: 'fe80::aa1a:2eee:feba:1c39' },
  tap0: { IPv4: '10.1.1.7', IPv6: 'fe80::ddf1:a9a1:1242:bc9b' } }