I have written a Node.js socket.io routine which will be called by a python socket io routine from my raspberry pi. It will communicate both ways. At the moment when I run these two routines on localhost it works fine. However when I deploy the server application to cloudfoundry and change the SocketIO connection link to cloudfoundry it does not work. Below is the client python
from socketIO_client import SocketIO
def on_updatepi_response(*args):
print 'updatepi'
def on_receivepi_response(*args):
print 'receiveepi'
with SocketIO('raspinode-server.cloudfoundry.com', 8080) as socketIO:
socketIO.on('receivepi', on_receivepi_response)
socketIO.on('updatepi', on_updatepi_response)
socketIO.emit('sendrabbit','testdata')
socketIO.wait(seconds=1)
I know cloudfoundry can be a bit strange as my first idea was to use rabbitmq but it is tied to the VCAP_SERVICES idea. However I did not think such a restriction would be there on a Node.js page.
Let me know if there is anything wrong with the above code and if not how can i get my external pi to send reading to my cloud app ?
Server Code is listed below though it is not relevant. It responds on localhost...I know the rabbitmq code is not hooked up yet
var express = require('express');
var app = express();
var server = require('http').createServer(app);
var amqp = require('amqp');
var io = require('socket.io').listen(server)
function rabbitUrl() {
if (process.env.VCAP_SERVICES) {
conf = JSON.parse(process.env.VCAP_SERVICES);
return conf['rabbitmq-2.4'][0].credentials.url;
}
else {
return "amqp://localhost";
}
}
var port = process.env.VCAP_APP_PORT || 3000;
var messages = [];
function setup() {
var exchange = conn.exchange('cf-demo', {'type':'fanout', durable:false}, function(){
var queue = conn.queue('', {durable:false, exclusive:true},
function() {
queue.subscribe(function(msg) {
messages.push(htmlEscape(msg.body));
if (messages.length > 10) {
messages.shift();
}
});
queue.bind(exchange.name, '');
});
queue.on('queueBindOk', function() {httpServer(exchange);});
});
}
server.listen(8080);
io.sockets.on('connection', function(socket){
// when the client emits sendrabbit, this listens
socket.on('sendrabbit', function(data)
{
// we tell the client to execute updatepi with 2 parameters
io.sockets.emit('updatepi', socket.username, data)
});
socket.on('disconnect', function()
{
socket.broadcast.emit('updatepi', 'SERVER', socket.username + ' has disconnected');
});
});
It's my understanding that your server should listen on the port Cloud Foundry assigns it (available in an env var). You can't assume it will be 8080. Then the client talks to raspinode-server.cloudfoundry.com (no port) and Cloud Foundry routes it to the correct place.
Related
guys, I had to implement WebSockets using channels in Django,but even after the connection is established successfully, WebSocket.send method is not working in javascript and it works only inside websocket.onopen
here's my javascript code for the socket
let noteSocket = null
function connect(){
noteSocket = new WebSocket('ws://' + window.location.host + `/ws/mycourses/{{
course.productId }}/chapters/{{ last_followed.chapter.chapterId }}/lessons/{{
last_followed.lessonId }}/notes/`)
noteSocket.onopen = function(e) {
console.log("Successfully connected to the WebSocket.");
}
noteSocket.onclose = function(e) {
console.log("WebSocket connection closed unexpectedly. Trying to reconnect in
2s...");
setTimeout(function() {
console.log("Reconnecting...");
connect();
}, 2000);
};
noteSocket.onmessage = function(e){
const data = JSON.stringify(e.data)
renderNote(data.note, data.timestamp)
}
}
after executing the connect function I get these in the Django development server terminal
WebSocket CONNECT /ws/mycourses/879521fa-75f9-4c95-8b61-039f7503ecae/chapters/91a12b16-35f7-4702-a002-35b228010a94/lessons/90a125ad-570e-437e-ac67-46cdeb55a068/notes/ [127.0.0.1:53424]
and I get from my browser console:
Successfully connected to the WebSocket.
I am using google chrome, and my os is arch Linux(note: I even tried in firefox but it didn't work)
So this is what I am trying to do, I want to be able to send a message in a browser towards a python script. I've got to the point where I can send a message in the browser and the server sees it. For testing purposes I used io.emit('input', data) to send the data towards my python script but nothing happens on the python side.
script.py:
import socketio
sio = socketio.Client()
#sio.event
def connect():
print('connected')
#sio.on("input")
def on_input(key):
print(key)
sio.connect('http://192.168.2.9:5000', namespaces=['/justin'])
server.js:
const express = require('express')
const app = express();
const http = require('http').createServer(app);
const io = require('socket.io')(http);
var justin = null;
app.use(express.static('public'));
io.of('/justin').on('connection', function(socket){
console.log('justin connected');
justin = socket;
});
io.on('connection', function(socket){
console.log('a user connected');
socket.on('event', (data) => {
io.emit('input', data)
})
socket.on('disconnect', () => {
//
})
});
http.listen(5000, function(){
console.log('listening on *:5000');
});
Is there something I'm not seeing or is this just not possible?
Thanks in advance!
Now my project use Django as API and NodeJs (SocketIO) as server which require Realtime for pushing Notifications
I try pushing Notifications to Node.js Socket.io using Redis PubSub but not success. Please check out my code error:
My Python code. I publish to myChannel sample message:
def test_vew(request):
REDIS_SERVER = redis.Redis(host='localhost', port=6379, db=0)
REDIS_SERVER.publish("myChannel", "Demo Message")
return Response({ "success": True }, status=200)
My NodeJS Code:
var app = require('http').createServer()
const PORT = process.env.PORT || 3000;
var redis = require('redis').createClient();
const server = app.listen(3000, () => console.log('listening on port 3000'))
//sockets
const io = require('socket.io').listen(app)
redis.subscribe('myChannel', (message) => {
console.log(`Got message ` + message)
})
io.sockets.on("connection", function(socket) {
console.log("A User Connected to SocketIO");
redis.on("pmessage", function(pattern, channel, message) {
console.log(channel, message);
});
});
When I run function in Django, My NodeJS Socket Subcribe can't grab message (Nothing log in console). I don't know the reason.
Hi i am copying parts of the github project multichat from the creator of django channels.
I am making slight changes to the code like not using jquery, renaming of some consumers and such.
I have literally no errors when running the code however when i join the page and the JS creates a websocket it says simply
[2017/08/03 13:13:48] WebSocket HANDSHAKING /chat/stream [127.0.0.1:37070]
[2017/08/03 13:13:48] WebSocket CONNECT /chat/stream [127.0.0.1:37070]
Which one would think is fine ofcourse... However i'n my connect function i have a print("********CONNECTED**********"), wich is nowhere to be seen in the console. It simply doesn't run the function i have told it to when someone connects but it still says the person connected and it throws no errors.
This is the main routing:
channel_routing = [
include("crypto_chat.routing.websocket_routing", path=r"^/chat-stream/$"),
include("crypto_chat.routing.chat_routing"),
]
Routing from app:
websocket_routing = [
route("websocket.connect", ws_connect),
route("websocket.receive", ws_receive),
route("websocket.disconnect", ws_disconnect),
]
chat_routing = [
route("chat.receive", chat_send, command="^send$"),
route("chat.receive", user_online, command="^online$"),
Connect Consumer:
#channel_session_user_from_http
def ws_connect(message):
# only accept connection if you have any rooms to join
print("******************CONNECT*************************''")
message.reply_channel.send({"accept": True})
# init rooms - add user to the groups and pk num to the session
message.channel_session['rooms'] = []
for room in Room.objects.get(users=message.user):
room.websocket_group.add(message.reply_channel)
message.channel_session['rooms'].append(room.pk)
print(message.channel_session['rooms'])
Heres JS (note: i am using the JS extension that is available on the project website also):
function send_msg(){
var msg=document.getElementById('msg_input').value;
console.log("sending msg" + msg);
webSocketBridge.send({
"command": "send",
"room": "1",
"message": msg
});
}
// logging
var ws_path = "/chat/stream";
console.log("connecting to " + ws_path);
// connect
var webSocketBridge = new channels.WebSocketBridge();
webSocketBridge.connect(ws_path);
// listen loop
webSocketBridge.listen(function(data)
{
// read json file and act accordingly
if(data.error){
// post error message in chat
console.log("Error - " + data.error);
return;
}
// handle if the user comes back online
if(data.online){
console.log("User is online");
}
else if(data.offline){
console.log("User offline");
}
else if(data.message){
console.log("Got message");
}
else{ console.log("Unknown message type"); }
});
// Helpful debugging
webSocketBridge.socket.onopen = function () {
console.log("Connected to chat socket");
};
webSocketBridge.socket.onclose = function () {
console.log("Disconnected from chat socket");
}
Websocket paths should match on server and client side. On server side, you have /chat-stream/ and on client side /chat/stream. These should match. Also, make sure you don't forget the trailing slash as django explicitly requires it.
I trying to send sensor data (in python) from my raspberry pi3 to my local node server.
I found a module for python called requests to send data to a server.
Here I'm trying send the value 22 (later there will be sensor data) from my raspberry pi3 to my local node server with socket.io.The requests.get() works but the put commmand doesn't send the data.
Can you tell me where the mistake is ?
#!/usr/bin/env python
#
import requests
r = requests.get('http://XXX.XXX.XXX.XXX:8080');
print(r)
r = requests.put('http://XXX.XXX.XXX.XXX:8080', data = {'rasp_param':'22'});
In my server.js I try to get the data but somehow nothing getting received
server.js
var express = require('express')
, app = express()
, server = require('http').createServer(app)
, io = require('socket.io').listen(server)
, conf = require('./config.json');
// Webserver
server.listen(conf.port);
app.configure(function(){
app.use(express.static(__dirname + '/public'));
});
app.get('/', function (req, res) {
res.sendfile(__dirname + '/public/index.html');
});
// Websocket
io.sockets.on('connection', function (socket) {
//Here I want get the data
io.sockets.on('rasp_param', function (data){
console.log(data);
});
});
});
// Server Details
console.log('Ther server runs on http://127.0.0.1:' + conf.port + '/');
you are using HTTP PUT from Python, but you are listening with a websocket server on nodejs side.
Either have node listening for HTTP POST (I'd use POST rather than PUT):
app.post('/data', function (req, res) {
//do stuff with the data here
});
Or have a websocket client on python's side :
ws = yield from websockets.connect("ws://10.1.10.10")
ws.send(json.dumps({'param':'value'}))
A persistant websocket connection is probably the best choice.