How to connect node app to server via socket.io? - node.js

Question

I have a simple app running on docker container. This container is not running all the time. It starts, does certain job and stops. When it is up, I would like to connect it to a server via socket.io. I have tried to use socket.io-client but still unable to make it works. This is my app code:
var docker_host_ip = process.env.DOCKER_HOST_IP;
var address = 'http://' + docker_host_ip +":" + port;
console.log("console : " + address);
var socket = require('socket.io-client')(address);
socket.on("disconnect", function(){
console.log("disconnected ");
});
socket.on("connect_failed", function(err){
console.log("err : " + err);
});
socket.on('connect', function(){
console.log("connected");
});
socket.on('news', function(data){
console.log("data : " + data);
socket.emit("news", {docker: "This is docker"});
});
socket.emit("news", {docker: "This is docker"});
socket.on('error', function (err) {
console.log(err);
});
I used this https://github.com/socketio/socket.io-client.
var port = 4000;
app.use(express.static('.'))
var http = require('http').Server(app);
var io = require('socket.io')(http);
io.on('connection', function(socket){
socket.emit("news", {"hello": "hello"});
socket.on("news", function(data){
console.log( "new " + data);
io.sockets.emit("news", data);
});
socket.on('disconnect', function() {
console.log('Got disconnect!');
});
});
app.get("/", function(res, req){
req.sendFile(path.join('/index.html'));
});
http.listen(port, function(){
console.log('listening on *' + port);
});
My app is not showing any error, but not message is sent. My server is working correctly through browser (with socket.io).
Can someone please tell me what is wrong ?

Answer 1

You have two same socket.emit message names, I guess the server send the message first.
server
socket.emit("news", {"hello": "hello"});
socket.on("news1", function(data){
console.log( "new " + data);
io.sockets.emit("news2", data);
});
client
socket.on('news', function(data){
console.log("data : " + data);
socket.emit("news1", {docker: "This is docker"});
});
socket.on('news2', function(data){
console.log("data : " + data);
});