使用 createServer() 时如何获取 node.js 服务器可用 IP

Question

When I was starting a simple server using:

http-server -S -C cert.pem

I was getting a list of available IPs and I could choose one to connect to:

Starting up http-server, serving ./ through https
Available on:
  https://192.168.1.2:8080
  https://169.254.187.206:8080
  https://169.254.74.61:8080
  https://127.0.0.1:8080
Hit CTRL-C to stop the server

How can I get the same list when using createServer()?

I tried this to get one address:

var server = https.createServer(options, function(request, response) {
  var uri = url.parse(request.url).pathname, 
      filename = path.join(process.cwd(), uri);
  
  fs.exists(filename, function(exists) {
    if(!exists) {
      response.writeHead(404, { "Content-Type": "text/plain" });
      response.write("404 Not Found\n");
      response.end();
      return;
    }
 
    if (fs.statSync(filename).isDirectory()) 
      filename += '/index.html';
 
    fs.readFile(filename, "binary", function(err, file) {
      if(err) {        
        response.writeHead(500, {"Content-Type": "text/plain"});
        response.write(err + "\n");
        response.end();
        return;
      }
      
      var mimeType = mimeTypes[filename.split('.').pop()];
      
      if (!mimeType) {
        mimeType = 'text/plain';
      }
      
      response.writeHead(200, { "Content-Type": mimeType });
      response.write(file, "binary");
      response.end();
    });
  });
    
}).listen(parseInt(port, 10));
    
var ip = server.address();
    
console.log("\n\n Static file server running at:\n address: " + ip.address + "\n family: " + ip.family + "\n port: " + ip.port + "\n\n Hit CTRL+C to stop the server");

and I got:

Static file server running at:
address: undefined
family: IPv6
port: 8080

Hit CTRL+C to stop the server

Today I spent one hour trying to figure out why I can no more connect via WIFI to my local server. It turned out that somehow the address I was using https://192.168.1.2:8080 had changed to https://192.168.1.3:8080 without adding any devices...

Answer 1

i don't have enougth reputation to comment so i put it here what i think could help you.

First of all, you should assign a static ip to your machine, you could either:

• Define in your computer an IP instead of relying on the DHCP service of your router
• Configure your DHCP (probably in your routeur config) to always give you the same IP address (static DHCP)

Then when you use listen() you can put your fixed ip as: listen(8080, 192.168.1.2)

Answer 2

You can get all the network interfaces that have an address using networkInterfaces() from the os module.

Documentation: https://nodejs.org/api/os.html#os_os_networkinterfaces

If you check http-server 's source code , it's doing something like this:

var os = require('os');
var ifaces = os.networkInterfaces();

Object.keys(ifaces).forEach(function (dev) {
  ifaces[dev].forEach(function (details) {
    if (details.family === 'IPv4') {
      console.log(details.address);
    }
  });
});