Unable to connect to Mosquitto over Websocket
Question
I am unable to connect to my local Mosquitto 1.4.10 broker from a JavaScript client over a Websocket.
The same JavaScript client is successfully connecting to the public broker at test.mosquitto.org on port 8080 over a Websocket.
The MQTT protocol connection on port 1883 is working fine, which I tested using mosquitto_pub and mosquitto_sub.
My broker is set up within a VirtualBox running Ubuntu 14.04.
I have libwebsockets installed on the same virtual machine.
My local broker was compiled with WITH_WEBSOCKETS:=yes in the config.mk file
I am loading the JavaScript client web page from the same virtual machine from a Firefox browser and seeing the following error message in the browser console:
Firefox can't establish a connection to the server at ws://localhost:8080/mqtt
Your suggestions on fixing this will be greatly appreciated.
Thanks.
Here is my Mosquitto .conf file:
port 1883
listener 8080
protocol websockets
log_type all
websockets_log_level 1023
connection_messages true
Here is the Mosquitto server's log (with websockets logging level set to 1023, and verbose logging turned on - no messages appear when I load the JavaScript web page):
1481381105: mosquitto version 1.4.10 (build date 2016-12-10 18:47:37+0530) starting
1481381105: Config loaded from /etc/mosquitto/mosquitto.conf.
1481381105: Opening websockets listen socket on port 8080.
1481381105: Initial logging level 10231481381105: Libwebsockets version: 2.1.0 manavkumarm@manav-alljoyn
1481381105: IPV6 not compiled in
1481381105: libev support not compiled in
1481381105: libuv support not compiled in
1481381105: Threads: 1 each 1024 fds
1481381105: mem: platform fd map: 4096 bytes
1481381105: Compiled with OpenSSL support
1481381105: Creating Vhost 'default' port 8080, 3 protocols, IPv6 off
1481381105: Using non-SSL mode
1481381105: Listening on port 8080
1481381105: mem: per-conn: 376 bytes + protocol rx buf
1481381105: canonical_hostname = mqtt
1481381105: Opening ipv4 listen socket on port 1883.
1481381105: Opening ipv6 listen socket on port 1883.
Here is the JavaScript source code:
<html> <body> <script src="mqttws31.js"></script> <script> try { // Create a client instance console.log("Creating client object..."); client = new Paho.MQTT.Client("localhost", Number(8080), "manav"); //client = new Paho.MQTT.Client("test.mosquitto.org", Number(8080), "manav"); // set callback handlers console.log("Setting handlers..."); client.onConnectionLost = onConnectionLost; client.onMessageArrived = onMessageArrived; // connect the client console.log("Connecting..."); client.connect( { onSuccess: onConnect, mqttVersion: 4 }); } catch (e) { console.log("Error: " + e.description); } // called when the client connects function onConnect() { // Once a connection has been made, make a subscription and send a message. console.log("Connected"); setTimeout( function() { client.subscribe("world"); message = new Paho.MQTT.Message("Hello"); message.destinationName = "world"; client.send(message); //client.disconnect(); }, 5000); } // called when the client loses its connection function onConnectionLost(responseObject) { if (responseObject.errorCode !== 0) { console.log("Connection lost: " + responseObject.errorMessage); } } // called when a message arrives function onMessageArrived(message) { console.log("Received Message: " + message.payloadString); client.disconnect(); } </script> <h1>My MQTT Websockets Example</h1> </body> </html>
1 answers
solution1
-1 2019-01-21 21:17:24
I see I am little bit late on answer.
MQTT's port for websocket is 1884 or something else, you have 8080. Maybe thats the problem.
Isnt 8080 a reserved TCP port?
Also, I know you have javascript code, but its paho. I was able to make publisher(it uses same class like subscriber so it must be on subscriber side too - this is just assumption though) work on websockets with paho python client which must be initialized with defining transport parameter. -> communicating with browser(see below for javascript)
mqtt.Client(transport='websockets')
Leaving that parameter MQTT assumes using TCP
mqtt.Client()
Also:
Config on my broker:
# Place your local configuration in /etc/mosquitto/conf.d/
#
# A full description of the configuration file is at
# /usr/share/doc/mosquitto/examples/mosquitto.conf.example
pid_file /var/run/mosquitto.pid
persistence true
persistence_location /var/lib/mosquitto/
log_dest file /var/log/mosquitto/mosquitto.log
include_dir /etc/mosquitto/conf.d
listener 1883
listener 1884
protocol websockets
I found my very old Javascript with paho-mqtt. It was working, so I just put it here. Its subscriber and publisher at the same time. Together with the config, It was working like charm.
class sub{
constructor(hostname,port,clientid,topic){
this.buffer = []
this.hostname=hostname;
this.port=port;
this.clientid = clientid;
this.topic = topic;
this.client = new Paho.MQTT.Client(hostname,port, clientid);
// set callback handlers
this.client.onConnectionLost = this.onConnectionLost;
this.client.onMessageArrived = this.onMessageArrived.bind(this);
// connect the client
this.client.connect({onSuccess:this.onConnect});
}
onConnect(){
console.log('OnConnect');
}
onConnectionLost(responseObject) {
if (responseObject.errorCode !== 0) {
console.log("onConnectionLost:"+responseObject.errorMessage);
}
}
onMessageArrived(message) {
console.log("onMessageArrived:"+message.payloadString);
this.buffer.push(JSON.parse(message.payloadString));
}
subsribe(){
this.client.subscribe(this.topic)
}
publish(message){
console.log(message)
var mg = new Paho.MQTT.Message(JSON.stringify(message));
mg.destinationName = this.topic;
this.client.send(mg);
}
}
var x
x = new sub('xx.xx.xx.xx',1884,'clientID','LED');
function on(){
x.publish({'LED':'ON'});
}
function off(){
x.publish({'LED':'OFF'});
}
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