I'm trying this simple websocket example on Google Chrome:
var wsUri = "ws://echo.websocket.org/";
var output;
function init() {
output = document.getElementById("output");
testWebSocket();
}
function testWebSocket() {
websocket = new WebSocket(wsUri);
websocket.onopen = function(evt) {
onOpen(evt)
};
..............
..............
function onOpen(evt) {
writeToScreen("CONNECTED");
doSend("WebSocket rocks");
}
function onClose(evt) {
writeToScreen("DISCONNECTED");
}
window.addEventListener("load", init, false);
But i always receive only DISCONNECT!
There is something wrong?
Do I have to enable WebSockets protocol in my local Apache? If yes how to?
This server is not reliable. It even fails on their own demo page for Chrome 14.
The response for a WebSockets request of Chrome 14 is this, which is obviously not correct:
HTTP/1.1 200 OK
Server: Kaazing Gateway
Date: Tue, 27 Sep 2011 14:07:53 GMT
Content-Length: 0
Note that Chrome just switched to a new draft of the WebSockets protocol, which is a complete overhaul. This means that the server has to return a different handshake response and also has to decode messages that are sent, which was not the case with the previous draft. It might just be that they did not upgrade their server yet.
What you probably want is setting up your own server which is compliant with the new draft and test it on that server.
There are a lot of libraries for WebSockets servers popping up everywhere; you can have a look here and pick the server language of your choice.
You need to specify that websocket is a variable. Change this line:
websocket = new WebSocket(wsUri);
to this:
var websocket = new WebSocket(wsUri);
Hope it helps. This solved some problems for me.
Related
I'm fairly new to a lot of this stuff and am trying to figure it out.
I have a hosted domain at <my.domain.com>. I host a game at this address that users can go to that address and the game loads in the browser for them.
On the same server I am running an Express nodejs (we'll call this HTTP SERVER) server to receive HTTP requests.
Also on the same server I am running a socket server using the Socket.io (we'll call this SOCKET SERVER) library.
HTTP SERVER can connect to SOCKET SERVER via localhost:<port> and they can communicate back and forth. I can send requests from my mobile device to HTTP SERVER which forwards those request to SOCKET SERVER and get a response back on the mobile device.
My problem now is I need to create another connection to SOCKET SERVER from my hosted game at <my.domain.com>. However, when I attempt to connect to localhost:<port> like I do from HTTP SERVER I get an ERR_CONNECTION_REFUSED error. I am assuming this has to do with with the host name being different. I've attempted to add
app.use(function(req, res, next) => {
res.header('Access-Control-Allow-Origin', '*');
});
But that doesn't seem to help. I'm not really sure where to go from here.
Socket server app.js
const app = require('express')();
const server = require('http').Server(app);
const io = require('socket.io')(server);
app.use(function(req, res, next) {
res.header('Access-Control-Allow-Origin', '*');
});
server.listen(8082);
io.on('connection', (socket) => {
console.log(`Socket server 'connection' event`);
});
Code in HTTP SERVER that does properly connect and send/receive messages
var socket = require('socket.io-client')('http://localhost:8082');
socket.on('connect', () => {
console.log(`HTTP server - 'connect' event to socket server`);
});
This is a javascript file that the game loads as an add-on. Hooks is provided by the game as an EventEmitter. I do not have direct access to the HTML pages the game displays, though I can manipulate them via this javascript add-on file.
let socket;
// a game hook when it's initialized
Hooks.on("init", function() {
// don't have direct access to game pages, so create a script tag and load
// the socket.io client library
const scriptRef = document.createElement('script');
scriptRef.setAttribute('type', 'text/javascript');
scriptRef.setAttribute('onload', 'window.socketLibraryLoaded()');
scriptRef.setAttribute('src', 'https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.3.0/socket.io.js');
document.getElementsByTagName('head')[0].appendChild(scriptRef);
});
// handler for when library is loaded
window.socketLibraryLoaded = () => {
log('Socket library loaded');
// i assume this address is wrong since the host of the game is <my.domain.com> and it's trying to connect to localhost
socket = io('https://localhost:8082');
socket.on('connect', () => {
log('Connected to socket server');
});
socket.on('connect_error', error => {
log(error);
});
}
So after banging my head on the wall for more than 10 hours over this I finally found the issue. And of course a simple user error.
The CORs error wasn't really the problem. I was getting that error because the NGINX proxy was erroring which caused the proper headers not to get sent back so the browser showed that error.
The issue was that in one place in my NGINX configuration I was using 127.0.0.0 instead of 127.0.0.1
I'm trying to connect to websockets in heroku but it's saying Error during websocket handshake: Unexpected response code: 503. The error in Dev Tools is 'Service unavailable'.
Server code
var wss = new WebSocketServer({server: app, port:5001});
Client code(I am replacing the port to 5001 as well)
var host = location.origin
.replace(/^http/, 'ws')
.replace('5000','5001');
var ws = new WebSocket(host);
I've did the same in development and I managed to connect. Any help to troubleshoot? Thanks.
Apparently, this was a stupid mistake from my side. What I did was follow the example on here and everything was ok..
Basically, I omitted this part from my code:
// app.listen(config.port, function(){
// console.log("App started on port " + config.port);
});
and included this instead
var server = http.createServer(app);
server.listen(config.port);
I am running Charles to inspect HTTP traffic between a node js client and a service running locally on my machine (a Mac). I am able to access the service but don't see any trace in Charles. I have tried replacing localhost with my machine's IP name but still no trace. If I type the service URL in Chrome I do see a trace. Anyone knows how to fix this?
Here is my nodejs code:
var thrift = require('thrift'); // I use Apache Thrift
var myService = require('./gen-nodejs/MyService'); // this is code generated by thrift compiler
var transport = thrift.TBufferedTransport();
var protocol = thrift.TBinaryProtocol();
var connection = thrift.createHttpConnection("localhost", 5331, {
transport : transport,
protocol : protocol,
path: '/myhandler',
});
connection.on('error', function(err) {
console.log(err);
});
// Create a client with the connection
var client = thrift.createHttpClient(myService, connection);
console.log('calling getTotalJobCount...');
client.getTotalJobCount(function(count)
{
console.log('total job count = ' + count);
});
and my proxy settings:
fixed this myself with help of this link. Charles intercepts the traffic crossing the system proxy which is 127.0.0.1:8888 on my mac. Here is proper code:
// give path to the proxy in argument to createHttpConnection
var connection = thrift.createHttpConnection('127.0.0.1', 8888, {
transport : transport,
protocol : protocol,
path: 'http://localhost:5331/myhandler', // give the actual URL you want to connect to here
});
In addition need to use thrift.TBufferedTransport instead of thrift.TBufferedTransport() and thrift.TBinaryProtocol instead of thrift.TBinaryProtocol()
I am currently getting this error below in Chrome console, but it still connects successfully with SignalR. Any reason why I am getting this error?
JS Hub Connection
scheduleHub = $.connection.scheduleHub;
scheduleHub.client.viewing = function (name, message) {
app.showWarning(message, name, function () {
app.refreshHash();
});
};
if ($.connection.hub && $.connection.hub.state === $.signalR.connectionState.disconnected) {
$.connection.hub.qs = { "eventid": options.eventId };
$.connection.hub.start()
.done(function () {
alert('Connected');
//scheduleHub.server.viewing('wow', 'test');
})
.fail(function() { alert('Could not Connect!'); });
}
Chrome Console
WebSocket connection to 'ws://localhost:2222/signalr/connect?transport=webSockets&clientProtocol=1.4&eventid=23919&connectionToken=CV3wchrj88t6FdjgA%2BREdzEDIw0rhW6r2aUrb%2BI8qInsb3Y9BqQSOscPxfAZ2g0Dxl704usqdBBn%2BNSFKpjVNOtwASndOweD1kGWPCkWEbtJBMu%2B&connectionData=%5B%7B%22name%22%3A%22schedulehub%22%7D%5D&tid=5' failed: Error during WebSocket handshake: Unexpected response code: 500
Web Sockets initially starts by negotiating the websockets connection over HTTP. During this HTTP handshake, the web server probably raised an exception, anyway, it returns HTTP Status Code 500. Without a successful HTTP response, Chrome is unable to continue negotiating the web sockets connection.
Since SignalR works over multiple transports, and not just websockets, once websockets connection failed, it will have automatically have switched to try some other transport, like forever frame or polling, which is why your connection still works.
I am using SockJS-client. SockJS constructor takes a relative URL as
var ws= new SockJS('/spring-websocket-test/sockjs/echo', undefined,{protocols_whitelist: [transport]});
Where do we indicate that WSS:// be used instead of WS://. If I try absolute URL, it gives error :
XMLHttpRequest cannot load ws://localhost:8080/appname/app. Cross origin requests are only supported for HTTP.
_ws_onclose. wasClean: false code: 1002 reason: Can't connect to server
Not sure why getting this error. Any similar configuration needed on Spring Server Implementation?
Went through the sock JS client code :I went through the client code -sock JS takes care of it -if its HTTPS it uses WSS else it does WS
var that = this;
var url = trans_url + '/websocket';
if (url.slice(0, 5) === 'https') {
url = 'wss' + url.slice(5);
} else {
url = 'ws' + url.slice(4);
}
No need to pass WS or WSS (In fact not even HTTP/HTTPS) with the SockJS constructor -just relative URL is sufficient. SockJs client library takes care of it.
One more surprising fact I encountered, it appends "/websocket" at end of the URL -this gave me clue why I was not able to connect with java client using jetty websocket-client apis
Try this code.
var ws= new SockJS('http://localhost:8080/sockjs/echo', undefined,{protocols_whitelist: [transport]});