Node.js-Socket.io仅可通过本地主机访问

Question

When I run my Node.js script, I can only access it by using localhost:8083, while using the machine's IP address from another device results in a "This site cannot be reached". I am using the following Node.js server script :

var app = require('express')(),
    server = require('http').createServer(app),
    io = require('socket.io').listen(server),
    ent = require('ent'), // Blocks HTML characters (security equivalent to htmlentities in PHP)
    fs = require('fs');

// Loading the page index.html
app.get('/', function (req, res) {
  res.sendfile(__dirname + '/index.html');
});

io.sockets.on('connection', function (socket, username) {
    // When the username is received it’s stored as a session variable and informs the other people
    socket.on('new_client', function(username) {
        username = ent.encode(username);
        socket.username = username;
        socket.broadcast.emit('new_client', username);(err) {});
    });

    // When a message is received, the client’s username is retrieved and sent to the other people
    socket.on('message', function (message) {
        message = ent.encode(message);
        socket.broadcast.emit('message', {username: socket.username, message: message});
    }); 
});
console.log('Chat Socket.io running on port 8083');
server.listen(8083);

Here is the client script :

<script src = "http://code.jquery.com/jquery-1.10.1.min.js" > </script>
<script src="/socket.io / socket.io.js "></script>
<script>
    // Connecting to socket.io
    var socket = io.connect("10.254.17.115:8083");

    // The username is requested, sent to the server and displayed in the title
    var username = prompt('What\'s your username?');
    socket.emit('new_client', username);
    document.title = username + ' - ' + document.title;

    // When a message is received it's inserted in the page
    socket.on('message', function(data) {insertMessage(data.username, data.message)})

    // When a new client connects, the information is displayed
    socket.on('new_client', function(username) {
    $('#chat_zone').prepend(
        '<p><audio class="background" autoplay><source src="new-user.mp3" type="audio/wav"></audio><em>' + username + ' has joined the chat!</em></p>');
    })

    // When the form is sent, the message is sent and displayed on the page
    $('#chat_form').submit(function() {
        var message = $('#message').val();
        socket.emit('message', message); // Sends the message to the others
        insertMessage(username, message); // Also displays the message on our page
        $('#message').val('').focus(); // Empties the chat form and puts the focus back on it
        return false; // Blocks 'classic' sending of the form
    });

    // Adds a message to the page
    function insertMessage(username, message) {
        $('#chat_zone').prepend('<p><strong>' + username + '</strong> ' + message + '</p>');
    } 
</script>

Edit: Revised ports but they were not the issue. When I changed the var socket = io.connect to io() it worked.

Answer 1

This is likely an issue with your server (and/or network) firewall, not with node. Any time that you need to use a new port on your server, you'll need to open up any firewalls to allow traffic to that port.

A good place to start would be to download a port scanning utility (eg nmap ) onto the client that is trying to connect. Then point the utility to the server, to see what ports are open.

Once you can confirm that it's a port issue, work on opening up that port on the machine's firewall. After that, if you still cannot contact the machine, then a network firewall might be preventing the traffic from reaching the server.

If you still can't figure it out, you'll want to get some advice from a networking expert (not my area of expertise), so consider posting a question under Network Engineering . Also, consider adding some error handling to the above code; it might help you to track down what exactly the problem is, if not a firewall issue.

Hope that helps, ~ Nate

Answer 2

You don't need to call connect on the client side, when the client is served socket.io.js , it will attempt to connect automatically to the server from which the file was served, with a call to io();

Edit:

var socket = io();

Once the client has been served the socket.io.js, this is all you need to call. socket will be your socket object that is connected to the server, in this example.

Take a look at this simple example. You can see that in their client side examples, they only do var socket = io(); to connect back to the server.

Answer 3

客户端和服务器端口应匹配（8081和8083不匹配）:)