Develop Reference

Paho MQTT JS client loses connection to Mosquitto broker when I publish or receive message (error AMQJS0005E)

Bottom line up front: The Paho MQTT client sucessfully connects to my Mosquitto broker, but immediately disconnects when I try to publish a message or when it receives a message from a topic it's subscribed to. I've tried changing Mosquitto's listening port and authentication settings, and using two different versions of Paho MQTT, and I still have the same problem.
Now let's get into detail.
Intro: I'm making a dashboard for some facial recognition devices that communicate through MQTT. I set up a Mosquitto broker and I've had no problems connecting to it and communicating with the devices using the Paho MQTT client for Python (I made a kind of server to sync the device's info to a database). Now I'm making the web interface, so I added a WebSockets listener to my mosquitto.conf and wrote a script using the Paho MQTT library for Javascript to connect to it, subscribe to topic sgdrf/out, send a simple JSON message to topic sgdrf/in to get the list of online devices, and process the response of the Python server once it arrives.
Problem and attempted solutions: I ran the Django server, loaded the web page and opened the JS console to find that the MQTT client successfully connected to the broker but immediately disconnected when it tried to publish the message to topic sgdrf/in. Here's each line of console output with their explanations:
The message produced by the onSuccess function, which indicates that the client successfully connected to the Mosquitto broker:
Conexión exitosa al broker MQTT.
In the onConnected function, I added console.log(uri) to see the URI used by the client to connect to the broker. I got:
ws://localhost:61613/
After printing uri to console, I made the client subscribe to sgdrf/out and then print 'subscribed' to console:
subscribed
Then I call get_online_devices(mqtt_client), a function which creates a simple JSON string and publishes it to the topic sgdrf/in. But first, it prints the strign to the console so that I can check it (just in case):
{"operator":"GetOnlineDevices","messageId":96792535859850080000,"info":{}}
Then, when the publish method is actually executed, is when I get this error (captured by the onConnectionLost function):
Pérdida de conexión con el broker MQTT: AMQJS0005E Internal error. Error Message: message is not defined, Stack trace: No Error Stack Available (código: 5)
I checked the Mosquitto log file and it only says when a new client was connected and then when it was disconnected because of a socket error (each time for every page reload). Tail of /var/log/mosquitto/mosquitto.log:
1614796149: New connection from 127.0.0.1 on port 61612.
1614796149: New client connected from 127.0.0.1 as mqttx_53195902 (p2, c1, k60, u'admin').
1614796182: Socket error on client sgdrf_dashboard_8499, disconnecting.
1614796325: New client connected from ::ffff:127.0.0.1 as sgdrf_dashboard_1597 (p2, c1, k60, u'admin').
1614796325: Socket error on client sgdrf_dashboard_1597, disconnecting.
1614796336: New client connected from ::ffff:127.0.0.1 as sgdrf_dashboard_6565 (p2, c1, k60, u'admin').
1614796336: Socket error on client sgdrf_dashboard_6565, disconnecting.
1614796931: New client connected from ::ffff:127.0.0.1 as sgdrf_dashboard_9773 (p2, c1, k60, u'admin').
1614796931: Socket error on client sgdrf_dashboard_9773, disconnecting.
1614797168: Saving in-memory database to /var/lib/mosquitto/mosquitto.db.
I tried changing the listening port in mosquitto.conf, and enabling and disabling authentication, but it changes nothing. And obviously I've had to restart Mosquito every time I changed the config file. I don't think the problem is Mosquitto.
I have the same problem whether I use Paho MQTT version 1.1.0 or 1.0.3.
As an experiment, I commented out the call to get_online_devices in my Javascript so that it doesn't try to publish anything, reloaded the page and there was no error, as expected. Then, I used MQTTX to send a JSON message to the sgdrf/out topic to which the MQTT JS client is subscribed to, and it immediately disconnected with the same error message.
Code: At the bottom of the page (index.html) I have the following code (the original code has Django template tags to fill in some values, so this is the actual code received by the browser):
<!-- Paho MQTT -->
<script src="/static/js/paho-mqtt-min.js"></script>
<!-- Scripts -->
<script src="/static/js/dashboard.js"></script>
<script>
function get_online_devices(mqtt_client) {
cmd = {
operator: "GetOnlineDevices",
messageId: generate_random_number_n_exp(20),
info: {}
};
payload_string = JSON.stringify(cmd);
console.log(payload_string)
mqtt_client.publish("sgdrf/in", payload_string);
}
function add_device_to_list(device) {
// Omitted for brevity. It's not being used yet.
}
let mqtt_client = make_mqtt_client("localhost", 61613);
let connection_options = make_connection_options(
"admin",
"CENSORED_PASSWORD"
);
mqtt_client.onConnected = function(reconnect, uri) {
console.log(uri)
mqtt_client.subscribe("sgdrf/out");
console.log('subscribed');
get_online_devices(mqtt_client);
};
mqtt_client.onConnectionLost = mqtt_client_on_connection_lost;
mqtt_client.onMessageDelivered = mqtt_client_on_message_delivered;
mqtt_client.onMessageArrived = function (msg) {
// Omitted for brevity. Checks if the payload is a
// JSON object with the right data and calls
// add_device_to_list for each item of a list in it.
};
$(document).ready(function() {
mqtt_client.connect(connection_options);
$("#reload-device-list-btn").click(function() {
get_online_devices(mqtt_client);
});
});
</script>
The dashboard.js files mentioned above just has some functions that I think will be useful for other pages, so I separated them to a file:
// dashboard.js
function generate_random_number_n_exp(n) {
return parseInt(Math.random() * Math.pow(10, n), 10)
}
function make_mqtt_client(host, port) {
let client_id = "sgdrf_dashboard_" + generate_random_number_n_exp(4);
return new Paho.Client(host, port, '/', client_id);
}
function make_connection_options(user, password) {
let connection_options = {
userName: user,
password: password,
onSuccess: mqtt_client_on_success,
onFailure: mqtt_client_on_failure,
};
return connection_options;
}
function mqtt_client_on_success() {
console.log('Conexión exitosa al broker MQTT.');
}
function mqtt_client_on_failure(error) {
console.log(
'Fallo de conexión con el broker MQTT: ' + error.errorMessage
+ ' (código: ' + error.errorCode + ')'
);
}
function mqtt_client_on_connection_lost (error) {
console.log('Pérdida de conexión con el broker MQTT: ' + error.errorMessage
+ ' (código: ' + error.errorCode + ')'
);
}
function mqtt_client_on_message_delivered(msg) {
let topic = message.destinationName;
let payload = message.payloadString;
console.log("Mensaje enviado a " + topic + ": " + payload);
}
function mqtt_client_on_message_arrived(msg) {
let topic = message.destinationName;
let payload = message.payloadString;
console.log("Mensaje recibido de " + topic + ": " + payload);
}
Here are the contents of my mosquitto.conf file:
per_listener_settings true
listener 61612
allow_anonymous false
password_file /home/s8a/Projects/sgdrf/config/pwdfile.txt
listener 61613
protocol websockets
allow_anonymous false
password_file /home/s8a/Projects/sgdrf/config/pwdfile.txt
It just sets up a TCP listener and a WebSockets listener, both disallow anonymous connections, and authenticate using a pwdfile. As I said before, I have enabled and disabled anonymous connections, and changed the port number to 9001 and back to 61613, and I still have the same error.
Conclusion: I don't know what to do and this project's deadline is next week.

I feel kinda stupid, because it was really a trivial typing mistake. The problem is that the onMessageDelivered and onMessageArrived functions have msg as argument, but I wrote messagein the function body for some reason. That's what the "message is not defined" error meant, message is literally not defined. Anyway I fixed that and now it sends and receives messages without problems.
...
More detailed story: What was not trivial is how I figured it out.
I decided to get my hands dirty and opened the non-minified version of paho-mqtt.js. I looked for "Invalid error" and found where the error constant is defined, and two places where it's used in a catch block. In both catch blocks I noticed that there was a ternary operator checking if (error.hasOwnProperty("stack") == "undefined") but the true and false clauses were inverted, which is why I was getting "No Error Stack Available".
So I inverted the clauses, and indeed I got a stack trace in the console (maybe I should file a bug report to the Paho dev team when I can). The stack trace had my mqtt_client_on_message_delivered function right at the top, so I read it again and suddenly everything made sense. Then I felt stupid for wasting an afternoon on this.

web socket not working with SSL and WSS in javascript

I have implemented web socket using below code,
try {
console.log('wss://' + hostname + ':' + port + endpoint);
webSocket = new WebSocket(webSocketURL);
webSocket.onmessage = function (event) {
//console.log('send message successfully.');
var obj = JSON.parse(event.data);
append_data(obj, market_pair);
};
} catch (exception) {
console.log('Exception handle!');
console.error(exception);
}
My page is https supported so I am using wss protocol. but issue is it gives me error that "Firefox can’t establish a connection to the server at wss://domainname.com:4008/order.php"
if I will load the page using simple http and use ws in websocket then it is working fine but with wss it shows above error. same way in google chrome it will also not able to connect.
My ssl certificate is installed correctly in server and my hosting and domain provided in godaddy and they told me that certificate is installed correctly.
I am running server side socket in php and it is working fine just now able to connect to that socket port using wss://
I have found that I am not able to do handshak using my php code because my php file is running in background and the content I am getting by socket read is encrypted.
function doHandshake($received_header, $client_socket_resource, $host_name, $port) {
echo $received_header;
$headers = array();
$lines = preg_split("/\r\n/", $received_header);
foreach ($lines as $line) {
$line = chop($line);
if (preg_match('/\A(\S+): (.*)\z/', $line, $matches)) {
$headers[$matches[1]] = $matches[2];
}
}
$secKey = $headers['Sec-WebSocket-Key'];
echo $headers['Sec-WebSocket-Key'];
$secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
//$secAccept = base64_encode(sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'));
$buffer = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" .
"Upgrade: websocket\r\n" .
"Connection: Upgrade\r\n" .
"WebSocket-Origin: $host_name\r\n" .
"WebSocket-Location: wss://$host_name:$port/websocket/btc_boon_pair.php\r\n" .
"Sec-WebSocket-Accept:$secAccept\r\n\r\n";
socket_write($client_socket_resource, $buffer, strlen($buffer));
}
this is my handshak function $headers['Sec-WebSocket-Key'] is undefined because $received_header is encrypted.
can anyone suggest the solution of this issue? I have to run php file as daemon and want to connect using wss protocol.

Ok finally I solved the issue.
due to the SSL encryption it is not able to read socket in my php daemon file. So I get solution from below answer
https://serverfault.com/questions/804862/apache-mod-proxy-forward-secure-websocket-to-non-secure
we can use proxy pass in apache so it will send all request with /websocket to the other ws://host:port/
after this it is working perfectly.
Also make sure that domain name is not using proxy because due to that my above solution is not worked but After removing proxy from DNS settings it started working.

In my case, I was using a VPS on Dreamhost.com and thus couldn't change Apache configuration files. However, I used this library to start secure socket server via following code:
use WSSC\Components\ServerConfig;
use WSSC\WebSocketServer;
$config = new ServerConfig();
$config->setIsSsl(true)->setAllowSelfSigned(true)
->setCryptoType(STREAM_CRYPTO_METHOD_SSLv23_SERVER)
->setLocalCert("./tests/certs/cert.pem")->setLocalPk("./tests/certs/key.pem")
->setPort(8888);
$websocketServer = new WebSocketServer(new ServerHandler(), $config);
$websocketServer->run();
I filled cert.pem and key.pem files with proper values from Dreamhost dashboard -> Websites -> Secure Certificates section.

How to connect a node server without browser

I am using node-jet library as message broker using a websocket.
In my code, there is a deamon and there are peers connect to it. In libary documentation its says peers can connect either by websocket or trivial tcp connection (never used second one before)
Here is server code I try to connect (its running when I try to connect)
https://github.com/lipp/node-jet/blob/master/examples/todo/todo-server.js
Everything works fine if I run my peer javascript inside a browser however, I am not able to run it from console.
var peer3 = new jet.Peer({
url: 'wss://217.78.109.178:8090'
//url: (window.location.protocol === 'http:' ? 'ws://' : 'wss://') +
window.location.host
})
documentation says it will use trivial tcp if no url provided so I also tried this. Again works in browser but not standalone. Any idea ? how can I solve this problem ?
var peer3 = new jet.Peer({
})
$ node Peer.js
Peer: connect failed { no remote stack
name: 'jet.ConnectionClosed',
message: '',
url: 'https://github.com/lipp/node-
jet/blob/master/doc/peer.markdown#jetconnectionclosed'
}

Sample JavaScript can't connect to Ruby WebSocket server

I would like to fiddle with websockets a bit. I installed a Ruby gem called "websocket-ruby" (https://github.com/imanel/websocket-ruby) I started a pry / IRB session and typed:
require "websocket"
#handshake = WebSocket::Handshake::Server.new(:host => "localhost", :port => 8080,:secure=>true)
This starts a websocket server as far as I know. Then I opened in my browser the Javascript HTML page which attempt to connect to the server:
<!doctype html>
<html lang="en">
<head>
<title>Websocket Client</title>
</head>
<body>
<script>
var exampleSocket = new WebSocket("wss://localhost:8080");
exampleSocket.onopen = function (event) {
exampleSocket.send("Can you hear me?");
};
exampleSocket.onmessage = function (event) {
console.log(event.data);
}
</script>
</body>
</html>
But it says in the console log:
failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED
I tried different ports both in server and in the client respectively: 8081, 12345, but I always get this error message.

I have some idea about websocket and javascript, but not websocket-ruby.
I hope it will helpful you.
In nodejs.. server.js file, write below code
var WebSocketServer = require("ws").Server;
var wss = new WebSocketServer({port:8100});
console.log("websocket Server is Running...");
wss.on('connection', function connection(ws) {
// Store the remote systems IP address as "remoteIp".
var remoteIp = ws.upgradeReq.connection.remoteAddress;
// Print a log with the IP of the client that connected.
console.log('Connection received: ', remoteIp);
// Add a listener which listens for the "message" event.
// When a "message" event is received, take the contents
// of the message and pass it to the broadcast() function.
ws.on('message', wss.broadcast);
});
wss.broadcast = function(msg) {
wss.clients.forEach(function each(client) {
client.send(msg);
})
};
In javascript...
var SERVER_URL = 'ws://localhost:8100';
//instead of localhost you can also use IP address of your system
var ws;
function connect() {
alert('connect');
ws = new WebSocket(SERVER_URL, []);
// Set the function to be called when a message is received.
ws.onmessage = handleMessageReceived;
// Set the function to be called when we have connected to the server.
ws.onopen = handleConnected;
// Set the function to be called when an error occurs.
ws.onerror = handleError;
}
function handleMessageReceived(data) {
// Simply call logMessage(), passing the received data.
logMessage(data.data);
}
function handleConnected(data) {
// Create a log message which explains what has happened and includes
// the url we have connected too.
var logMsg = 'Connected to server: ' + data.target.url;
// Add the message to the log.
logMessage(logMsg)
}
function handleError(err) {
// Print the error to the console so we can debug it.
console.log("Error: ", err);
}
function logMessage(msg) {
// with the new message.
console.log(msg);
}
/** This is the scope function that is called when a users hits send. */
function sendMessage{
ws.send(msg);
};
connect();
in html use one button to send message to websocket server
<button onclick="sendMessage('Hi Websocket')">send message</button>

To the best of my knowledge, the Ruby code you presented does not start a Websocket server... what it does is initiate a server-side parser.
To start a server you need to use an actual websocket server.
ActionCable (with Rails) uses the websocket-ruby library to parse websocket events and it uses nio4r to operate the actual server.
Faye have a similar solution and em-websockets use the websocket-ruby gem with EventMachine.
Other Ruby Websocket servers include Iodine, which uses the C library facil.io. Iodine is used by the framework plezi as well as independently.
Since you were trying to run an echo server, here's a quick example using the Plezi framework (you can use it as middleware in Sinatra or Rails)...
...place the following in a config.ru file:
require 'plezi'
class WebsocketSample
# HTTP index
def index
'Hello World!'
end
# called when Websocket data is recieved
#
# data is a string that contains binary or UTF8 (message dependent) data.
def on_message(data)
puts "Websocket got: #{data}"
write data
end
end
Plezi.route '/', WebsocketSample
run Plezi.app
To run the server, call (ignore the $ sign, it marks this code as terminal code):
$ iodine
notice: Iodine requires a BSD / Unix / Linux machine, such as macOS, Ubuntu, etc'. It won't work on windows.

error on connecting to the server : socket io is not defined

i know there's been couple of question about the same problem , i've already check them .
i have very simple node.js chat app
i have a server running on 8000 port and it works fine
my client pages are html , they are running on apache and i'm using socket.io to connect them to the server and it works fine on the local host
but when i upload the app on the server i keep on getting this error in the firebug
io is not defined
var socket = io.connect('http://atenak.com:8000/');
or sometimes it doesn't show that but when i try to broadcast message from cliend i get this error :
socket is undefined
socket.emit('msg', { data: msg , user:'max' });
the only difference is i've changed the localhost with atenak.com !
here is my html code
var socket = io.connect('http://atenak.com:8000/');
var user = 'jack';
socket.on('newmsg', function (data) {
if(data.user == user )
{
$('#container').html(data.data);
}
});
function brodcast(){
var msg = $('#fild').val();
socket.emit('msg', { data: msg , user:'max' });
}
</script>
</head>
<body>
<div id="container"> </div>
<input id="fild" type="text"> <input name="" type="button" onClick="brodcast();">
</body>
i have included the sockt.io.js
src="http://atenak.com:8000/socket.io/socket.io.js"
and server is running ok which means socket.io is installed on the server
here is the live page
http://atenak.com/client.html

I'm getting:
> Uncaught ReferenceError: io is not defined client.html:7
x GET http://atenak.com:8000/socket.io/socket.io.js
indicating that your page cannot load http://atenak.com:8000/socket.io/socket.io.js; indeed, if you try to load that URL in the browser, you get a connection error. Make sure that your Node.js server (running Socket.IO) is accessible (e.g. ports not being blocked by a firewall, etc).

Seems port 8000 is not open on your host as per links below
Reverse ip check for atenak.com and Open port check

Socket.io need a javascript file and this file does not load correctly.
Here is the url: http://atenak.com:8000/socket.io/socket.io.js
In this file is defined the îo object.