I have used socket.io, Node.JS, and express to create a real-time chat application that I could view by creating a local server. However, instead of using a local server, I would like to point my client to an existent heroku service. How do I go about doing this?
When I do the following,
var spot = io("https://spotim-demo-chat-server.herokuapp.com");
all functions relating to connecting, disconnecting, username registration, and messaging seem to fail. They do not function in the chat nor do their console.log messages appear in terminal.
I have also considered creating a HTTP server and having it listen to the port and IP address of the heroku service with .listen(). However for my assignment, I was not provided with either of these values, simply the heroku url.
I'm not sure where you're having trouble without more code from you. I've setup a basic socket.io client as follows and can connect without issue. You can run it with the following to see just the client's messages DEBUG=spot-client node client.js or if you wish to see all the debug info from the socket client itself as well DEBUG=* node client.js. The latter might help you diagnose the issue further. Also be sure to install the socket.io-client and debug packages. Hope this helps!
const io = require('socket.io-client');
const debug = require('debug')('spot-client');
var spot = io("https://spotim-demo-chat-server.herokuapp.com");
spot.on('connect', function(){
debug("connected");
});
spot.on('event', function(data){
debug("event",data);
});
spot.on('disconnect', function(){
debug("disconnect");
});
Related
So, I am wondering if there is a way to connect to the mongoDB I have setup in my Cloud9 from an html. I mean, I have already connected to the db from the terminal and everything is working like a charm but I need to do some stuff inside my script in an html document and when I try calling the function which contains this code it does nothing
var MongoClient = require('mongodb').MongoClient
, format = require('util').format;
MongoClient.connect('mongodb://127.0.0.1:27017/ingesoft', function (err, db) {
if (err) {
throw err;
} else {
console.log("successfully connected to the database");
}
db.close();
});
I have saved the same code into a "file.js" and ran it from console using node file.js and it outputs into the console log "successfully connected to the database", plus the terminal which is running mongo's connection shows me one more connection to the db. The thing is, when I try to run that code inside my script it doesn't work. Sorry for my ignorance I am new to mongo.
Any help would be much appreciated
To simplify your question, here's what's going on:
node file.js containing the code in your question is working
pasting the same code to your html file is not
So, getting to the bottom of the issue, let's ask first: what's the difference between running node file.js and putting the code in html?
The difference is that node ... is running on your Cloud9 workspace (let's call it the server machine).
Your MongoDB server is also running on that server machine
The mongodb npm package you installed is also present on the server machine
The url: mongodb://127.0.0.1:27017/ingesoft references 127.0.0.1 which is the localhost for your server
whereas with the code on your browser:
The code is being run on your customer's machine
That machine doesn't have your Mongodb server
Browser's usually don't support require
You can do requires if you bundle code and use something like webpack or browserify. Did you perhaps do that?
If you did indeed package everything, was the mongodb package that you're requiring packaged?
Can the mongodb package be run from the client side?
The url: mongodb://127.0.0.1:27017/ingesoft references 127.0.0.1 which is the localhost for your customer's machine
Basically, as you can see from the above, the two are very different.
If you want to talk to your db, a lot of people go the following route:
Make a server application that implements some form of REST API
That REST API talks to your DB
Your client code knows how to talk to the REST API and get the required data
That way, you only talk to your MongoDB using your server, and the client can talk to your server via the internet.
This is, of course, an oversimplification, but I hope this resolves your confusion.
I'm trying to set up a simple "Hello world" node.js app.
I've created the following index.js file:
var app = require("express")();
var http = require("http").Server(app);
app.get("/", function(req, res){
res.send("<h1>Hello worlddddd</h1>");
});
http.listen(8080, function(){
console.log("listening on *:8080");
});
When I open up my local console, and perform node index.js, I get the message "listening on *:8080", as expected. I point my browser to localhost:8080, and I see the HTML page saying "Hello worlddd", as desired.
Now, I'm trying to do the same on my Virtual Private Server, so I can access the same app from different computers, but all I get is connection timeouts. I've followed these steps:
Install node.js on my VPS
Install express via npm install --save express#4.10.2
Upload my index.js file to the var/www/html folder on my server with IP 192.123.123.12 (an example, this isn't my real IP).
Access the server via PuTTY, and run node index.js, where I get "listening on *:8080", so I know node.js is working.
Now I point my browser to http://192.123.123.12:8080 and after about 20 seconds, I get the browser error: "The connection has timed out".
I've tried listening to port :80 instead, but I get the error that this port is already in use.
Does anybody know what I'm doing wrong? Am I using the wrong port? Am I pointing to the wrong URL? Do I need to modify my server preferences? (running Apache on CentOS). I've only found dozens of tutorials that teach you how to run a node.js app on your local computer(pointing the browser at localhost:8080), but I need it to run on my remote server so multiple computers can access the same app.
The issue is that your current filters (iptables) block traffic unless you explicitly allow it.
You just need to open port TCP 8080 inbound, and you should be able to reach your node.js server!
This must be an extremely common problem. I've seen various answers for this but none seem to work for me.
I have node installed on an apache server on Windows Azure. My app is built and ready to go (snippet below):
var express = require("express");
var app = express();
//example api call
app.get("/api/example", function(req, res){
//do some process
res.send(data);
});
app.listen(8080);
console.log("App listening on port 8080");
Now, when testing on my own computer, I could then go to localhost:8080, which works great. But now I've put it on the azure server I can't get an external domain to point to it properly. So for example, I have the domain:
framework.example.com
I've added this to my hosts file in Azure:
XXX.0.0.01 framework.example.com
Initially I tried also editing the http-vhosts.conf to point the domain to the correct directory. This worked for loading the frontend, but the app couldn't talk to the backend. API calls returned 400 not found errors.
I've also tried an Express vhost method but think I'm doing it wrong and don't fully understand it. What is the correct method?!
My app structure is like this:
- package.json
- server.js
- server
- files used by server.js
- public
- all frontend files
So to boot the server I run server.js which runs the code at the top. The server.js uses the below Express config to point to the public folder.
app.use(express.static(__dirname + "/public"));
Adding it to the hosts file in Azure won't help. You'll need to configure your domain's DNS to point to Azure. I'd recommend using the DNS Name of your Cloud Service instance. Your underlying VM IP address could change if you need to stop it for some reason, but your Cloud Service DNS name is configured to always route to your underlying VMs. That means you'll need to setup a CNAME with your DNS.
Read more about that here: Cloud Services Custom Domain Name
Next, you'll either need to host the node app on port 80, or put a proxy in front of it to handle that for you. Otherwise you'll be stuck typing framework.example.com:8080 which is not ideal. On linux, you'll likely need to be a privileged user to host on port 80, but you never want your node app to have root privileges. You can use authbind to work around this problem.
See an example of how to use it with node here: Using authbind with Node.js
All that being said, it seems like you're somewhat new with linux server management. If that's the case, I'd strongly recommend trying to use something like Azure Websites instead of a VM. You no longer have to manage the virtual machine OS. You simply tell it to host your application and it takes care of the rest. If you're using github, this is incredibly easy to test and iterate with. It does host on Windows under the hood, and that might problems for some applications, but I host all my node sites there (developed on Mac) without any issues.
So I'm trying to get chat working on my website, and when I was testing locally it worked great, because port 8080 on my localhost was available and all that good stuff. But now I pushed my code to my Heroku app, and when I try and load my chat page, I get the error stating that it can't get localhost:8080/socket.io/socket.io.js.
I've seen node.js /socket.io/socket.io.js not found
and tried the suggestions, but none worked, even moving the socket.io.js file into a resource file did not work. I'm guessing this is because I'm using express 4.0?
Any help would be appreciated
Thanks
Edit:
So to add more details, since my question could seem a little vague, here is my relevant app.js code:
var client = require('socket.io').listen(8080).sockets;
In my jade file for the chat page, I have:
script (src = `'http://localhost:8080/socket.io/socket.io.js`')
and later on
var socket = io.connect(`'http://localhost:8080`');
and all this works on localhost (I load up on port 5000, socket.io is connected to port 8080). I do this using 'foreman start' with the heroku toolbelt.
When I try and change these to work on heroku, it breaks and I'm not sure how to fix it. I hope this clarifies the question a bit.
Edit 2:
I'm running:
express 4.0.0
socket.io 0.9.16
node 0.10.x
Thanks
Do you have an explicit route in express which catches all other routes? Something like this perhaps:
app.get("/", handlers.home);
app.get("/..." ...);
...
app.get("*", handlers.error);
This might keep socket.io from being able to host it's own js file for the client. There is an easy way to fix this, since you probably already have a public or static folder setup in express. Something like:
app.use(express.static("public"));
Make a new folder called socket.io and copy over the appropriate socket.io.js file into said folder, and all should be well. However note that there are two files named socket.io.js!! So, if you see something like "Uncaught ReferenceError: require is not defined" it means you copied the "node-ey" server side file. Here is the correct client file to copy:
app_dir/node_modules/socket.io/node_modules/socket.io-client/dist/socket.io.min.js
Note #BHendricks: I would have just posted as a reply to your comment, but I currently lack the required reputation.
Edit:
The OPs question probably has more to do with the "localhost" issue. When connecting from a client (say your home IP), as far as your browser knows - localhost implies a connection with the machine which is locally hosting stuff. Since your home machine (or phone) does not host socket.io, this is failing.
What you need to do is have your server embed the socket connection information (either a fully qualified hostname, ip etc). This can be done when the server "renders" the page with the client connection.
What happens when you go to http://localhost:8080/socket.io/socket.io.js?
Does it 404? If it does you need to make sure you have it in a directory that Express is set to serve statically.
app.use(express.static(__dirname + '/public'));
Then put your socket.io.js file in public/socket.io/socket.io.js (relative to your app.js file)
Restart your server and see if that fixes it.
Basically, Express doesn't serve files statically from the file system unless you explicitly tell it where to map from.
I'd like to enable socket-based p2p communications between two or more different node.js application servers. I'm using socket.io to handle all such communication between a given server and the web application it serves - but what I'm looking for is a way to communicate server-to-server.
I had initially assumed it would be as easy as something like this:
var io = require("socket.io");
var socket = io.connect("my remote endpoint");
However, as it turns out the server-side socket.io implementation doesn't offer a "connect" method, only a listen method.
Why is this? Why can't I treat a node application server as a client to a socket.io server running elsewhere? Is there any way that I can achieve this functionality?
OK, so thanks to #pimvdb in the comments above I've got a workable solution.
Basically, the socket.io library that npm installs has a dependency on another module, called socket.io-client. In a standard socket.io installation this will be installed in node_modules/socket.io/node_modules/socket.io-client
However, it's also possible to say "npm install socket.io-client" and install it as its own first-class citizen library.
Then your usage looks like this:
var client = require("socket.io-client");
var socket = client.connect("http://myendpoint.com:3000/whatever");
socket.emit("test", "foo");
And everything works.
So, thanks man!
Just for clarification, this is an example with listeners and possibility to emit events (and without install again a module already installed)
var io = require('socket.io/node_modules/socket.io-client');
client = io.connect('http://'+CONFIG.host+':'+CONFIG.port);
client.on('connect',function() {
client.emit("test","foo");
});
Before you go full speed on socket.io for server-to-server communications.....
socket.io is engineered as a browser to server comm infrastructure. I'm far from certain it is the best solution for P2P server stuff. Plus, if you do server-to-server - why not just do Websockets? There are various websocket modules for node - e.g. https://github.com/einaros/ws