I have drupal site that communicates with Node.js server via sockets, so i have the following to load and send connection request in the header:
<script src="http://xx.xx.xx.xx:3000/socket.io/socket.io.js"></script>
...
socket = io.connect('http://xx.xx.xx.xx:3000');
This works well, however. I prefer my server ip and the port number is not exposed to the rest of the world. What is the approach to do so? Thank You
The short answer is :
You can not do this.
The longer explaination :
Your socket.io connection is like any other connection made to your server(s). It will be always visible in the developer tools of any other browser. You might want to use a proxy service for that, but in the end your socket.io server will always be exposed.
Nobody will ever read your JS code if he wants to get your socket.io IP-address, there are many other easier ways to do that.
Although you can always use the autoconnect feature of socket.io and just put
socket = io.connect();
Related
I would like to send messages from my Java server to my react-native clients.
I don't know exactly how to solve this. Should the server establish a connection to all clients via the IP addresses of the clients and send the message and then close the connection again? (Sounds the most sensible to me.)
I think that would be better than if the clients connected to the server and the connection should always be maintained. After all, it should run with high performance.
Basically, it doesn't make much sense for my system that the clients connect to the server, since only the server knows when and whether it is sending a message.
I've already tried working with websockets. However, it didn't seem to work without requests from clients.
The difficulty is to find a method that works with Java on the server side and JavaScript on the client side and that the connection is made from the server to the clients and not from the clients to the server. In addition, the transmission should work in real time.
Is that feasible? Are there any better ways? How can I do it?
I hope you can help me.
Greetings. Martin
The basic function of the system
There are multiple cloud based messaging platforms. One of them is Firebase from Google which is free (I guess). Check this out here. https://firebase.google.com/docs/cloud-messaging
You will find multiple tutorials to configure and use it in your react-native and Java server.
Architectural overview: https://firebase.google.com/docs/cloud-messaging/fcm-architecture
Another solution is writing your own logic using the WebSockets.
Lifecycle of message: https://firebase.google.com/docs/cloud-messaging/fcm-architecture#lifecycle_flow
the client i am working with has a node js tcp server working with gps trackers through raw tcp. This trackers can not be upgraded to use socket.io or any other library. They simply send raw data.
My work is to upgrade the client and admin communication, currently they login by console using netcat ip port and typing the command they want to execute.
My idea is to use vue since they woule like realtime communication and better ui/ux. I have no idea how to make a raw tcp tranport with vue. any help?
The short answer to this question, is that the browser cannot directly use raw TCP connections. If the browser is your only option you are probably out of luck.
However if you still want to use vue you have a couple of options. You could implement a kind of TCP-socket-bridge. Such as ws-tcp-bridge. You could also write your own middleware server to dispatch events in node.js, using something like the example here.
A third option would be to do something like electron-vue and use its node instance to relay the data to vue with a websocket or socket.io. Here is an example of an express server with electron.
Good luck, and sorry it isn't easier.
Im just thinking above my head here. But what about having maybe a bash script that post to a webhook back and forth. You can post to an endpoint and run a bash script behind cameras, and this same script post back to another webhook that you will be listening to. It wont be fast i believe but it will get the job done. You just have to manage the queue and the webhook listening. Also be sure to limit the webhook origin request to your app only.
Bash easily can save the output of a netcat command, and also this way you isolate the raw tcp communication, giving it an extra layer of security.
I'm creating an app where the server and the clients will run on the same local network. Is it possible to use web sockets, or rather more specifically, socket.io to have one central server and many clients that are running native apps
? The way I understand socket.io to work is that the clients read the web-pages that are served from the server but what happens when your clients become tablet devices running native apps instead of web pages in a browser?
The scenario I'm working with at the minute will have one central server containing a MEAN app and the clients (iPads) will make GET requests to the data available on the server. However, I'd also like there to be real-time functionality so if someone triggers a POST request on their iPad, the server acknowledges it and displays it in the server's client-side. The iPad apps will (ideally) be running native phonegap applications rather than accessing 192.168.1.1:9000 from their browser.
Is this technically possible to connect to the socket server from the native apps or would the devices have to send POST requests to a central server that's constantly listening for new 'messages'? I'm totally new to the whole real-time stuff so I'm just trying to wrap my head around it all.
Apologies if this isn't totally clear, it's a bit hard to describe with just text but I think you get the idea?
Correct me if I am wrong.
You have multiple iPads running native app. They send a POST request to your node JS server which is running in a computer in the same local network. Whenever the server receives a request from app, you want to display that a request has been received in your computer screen.
If my assumptions about the scenario is correct, then it is fairly easy to do. Here are the steps to do it.
Create a small webpage (front end). Load socket IO in the front end page like this -
<script type="text/javascript" src="YOUR_SERVER_IP/socket.io/socket.io.js"></script>
Then connect to server using var socket = io(). This should trigger connection event in your backend.
Handle all POST request from apps normally. Nothing special. Just add a small snippet in between. socket.emit('new_request', request_data). This sends new_request event to front end.
Handle the new_request in your front end using socket.on('new_request', function(request_data) { ... });. That's it. No need to add anything to your native app for realtime update.
The second step would be a little complicated as it is necessary to make socket variable available inside all POST requests. Since you chose node.js, I don't think you need any help with that.
Not totally clear on your project, but I'll try to give you some pointers.
An effective way to send data between native apps and a server is using a REST server. REST is based on HTTP requests and allows you to modify data on the server, which can connect to your database. The data returned is typically either JSON or XML formatted. See here for a brief intro: http://www.infoq.com/articles/rest-introduction
Android/iOS/etc have built in APIs for making HTTP requests. Your native app would send a request to the server, parse the response, and update your native UI accordingly. The same server can be used from a website using jQuery ajax HTTP requests.
Express.js is more suited to serving web pages and includes things like templating. Look into "restify" (see here: mcavage.me/node-restify/) if you just want to have a REST server that handles requests. Both run on top of node.js (nodejs.org).
As far as real-time communication, if you're developing for iOS look into APNS (Apple Push Notification Service). Apple maintains a persistent connection, and by going through their servers you can easily send messages to your app. The equivalent of this on Android is GCM (Google Cloud Messaging).
You can also do sockets directly if that's easier for you. Be careful with maintaining an open socket on a mobile device though, it can be a huge battery drain. Here's a library for connecting ObjC to Socket.IO using websockets, it may be useful for you: https://github.com/pkyeck/socket.IO-objc
Hope that helps!
To answer your question, it is definitely possible. Socket.io would serve as the central server that can essentially emit messages to all of the client. You can also make Socket.io listen for the messages from any of the clients and serve the emitted message to the rest of the clients.
Here's an example of how socket.io can be used. Simply clone, npm install, and run using 'node app.js'
All you have to do is to provide a valid server address when you connect your socket from the iPad clients:
var socket = io.connect( 'http://my.external.nodejs.server' );
Let us know if you need help with actual sending/receiving of socket events.
It is possible to connect to Websockets from your apps.
If you are using PhoneGap then you need a pluging that gives support to websockets in your app (the client) and then use websocket like normal way using Javascript see this.
If your app is native iOS look into this it could help you.
The primary use of the Sockets in your case is to be a bidirectional "pipe" between an app and server. There is no need of server sending the whole web-page to the native app. All what you need is to send some data from server to the client(app) in response to POST (or GET) request and then using this data on client side to update client's UI in real-time. If you are going to use moderate amount of devices (say tens of them), you may have connected all of them to the server permanently keeping individual socket connection open for every individual link server-to-app. Thus you may deliver data and update client's state in real time.
In fact web browsers also employ sockets to communicate to web servers. However as in general case there is no control on amount of concurrent clients in Internet, for the sake of limited networking resources conservation, servers do not keep sockets open for a long time, closing it just after the web-page was sent to client (or timeout has expired). That's how HTTP protocol works on the low level. The server waiting for the HTTP clients (browsers) by listening the 80 port, responding them by sending the whole web page content, then closing the connection and keep waiting for another requests on the same port.
In your case it's basically a good idea to use socket.io as it's a uniform implementation of sockets (ok WebSockets) on both client and server side. The good starting point is here
To use socket.io on the client side, usually we start a node.js server and go like this:
<script src="/socket.io/socket.io.js"></script>
or with specific port:
<script src="http://localhost:3700/socket.io/socket.io.js"></script>
Question is:
is it necessary to use node.js server to serve socket.io.js ?
...or is it possible to
make a local copy of socket.io.js instead of goes to server every single time we need socket.io?
like, we go to view source and copy everything we got from the source of script tag,
paste and save it as socket.io-local.js so that next time we use:
<script src="socket.io-local.js"></script>
will that work ?
Updates
Thanks for everyone's great response,
I'm asking this because in the case I'm involved, I don't actually have access to the server:
I am writing the client-side to connect to other developer's Socket Sever which is written in Java.
Therefore I'll have to think a way to work around the fact that I don't have a server there for me.
from what I've been testing,
this way seems to work but I really don't know what's happening behind the scene.
You obviously can host the socket.io client library anywhere and pull it in to a page. However, it will almost certainly not work with your Java-based server.
To understand why, you need to understand what socket.io is really doing behind the scenes; the client library is only a small part of it.
Socket.io actually defines and implements its own protocol for realtime communication between a browser and a server. It does so in a way that supports multiple transports: if—for example—a user's browser or proxy doesn't support WebSockets, it can fall back to long polling.
What the socket.io client actually does is:
Makes a XHR GET request for /socket.io/1. The server responds with a session ID, configured timeouts, and supported transports.
The client chooses the best transport that the user browser supports. In modern browsers, it will use WebSockets.
If WebSockets are supported, it creates a new WebSocket to initiate a WebSocket connection (HTTP GET with Upgrade: websocket header) to a special URL – /socket.io/1/websocket/<session id>.
If WebSockets aren't supported by the browser or fail to connect (there are lots of intermediaries in the wild like proxies, filters, network security devices, and so forth that don't support WebSocket requests), the library falls back to XHR long polling, and makes a XHR request to /socket.io/1/xhr-polling/<sesion id>. The server does not respond to the request until a new message is available or a timeout is reached, at which point the client repeats the XHR request.
Socket.io's server component handles the other end of that mess. It handles all the URLs under /socket.io/, setting up sessions, parsing WebSocket upgrades, actually sending messages, and a bunch of other bookkeeping.
Without all of the services provided by the socket.io server, the client library is pretty useless. It will just make a XHR request to a URL that doesn't exist on your server.
My guess is that your Java-based server just implements the WebSockets protocol. You can connect directly to it using the browser-provided WebSocket APIs.
It is possible that your server does implement the socket.io protocol – there are a few abandoned Java projects to do that – but that's unlikely. Talk with the developer of your server to find out exactly how he's implemented a "socket server."
A standalone build of socket.io-client is exposed automatically by the socket.io server as /socket.io/socket.io.js. Alternatively you can serve the file socket.io-client.js found at the root of this repository.
https://github.com/LearnBoost/socket.io-client
I have a module called shotgun-client that actually wraps socket.io. I needed to serve a custom client script as well as the socket.io client script, but I didn't want every user of my module to have to include multiple script references on their pages.
I found that, when installed, you can serve the generated client script from socket.io by reading the file /node_modules/socket.io/node_modules/socket.io-client/dist/socket.io.js. So my module adds a listener for its own URL and when it serves my custom client script it also serves the socket.io client script with it. Viola! Only a single script reference for the users of my module :)
While this is technically possible, I don't see why you'd need to do that. If you're concerned about reducing the data that goes over the wire, this change won't actually do much beyond the few characters saved in the shorter src tag. Simply changing the location of the JS file on the server won't actually improve performance - the JS has to be sent.
Proper caching (which Socket.IO has) will return a 304 Not Modified (and not re-send the JS file every time you load a page).
I don't quite know how to search this in google:
"client to client websocket connections"
"browser to browser websockets"
"websockets without a server"
Haha, is there a way for someone on a webpage in the browser to communicate directly to another person on a web page in the browser, without touching the server?
I am very familiar with socket.io, but that requires all clients emit messages to the server, which can broadcast them to the other connected clients. I am not familiar with the details of web sockets though, so maybe there's a way to communicate without sending messages through the server.
Is this possible? I just want to know the scope of web socket functionality, the limits you can take them too, etc.
Not Web Sockets, but four years later and now we've got browser-to-browser communication!
http://www.webrtc.org/
There are JS libraries built around it to make it easier (e.g. https://simplewebrtc.com/). However, it does still require a server to orchestrate connections.
I know this question is ancient, but it showed up in Google when I searched so it likely will for others!
This is not possible, you have to have the server in the middle.
For an application to accept connections, it has to have a server port open and listening for incoming requests. You cannot have a server socket exposed from a browser. I dont know if you can expose a server socket from within an applet. But even if you could, you would need to know the IP address of the other client for establishing a peer to peer connection.
Well, technically when you broadcast, the client emits to the server, the server broadcasts to everyone. I don't think with the current architecture of the web peer to peer connections like this is possible.
But it is possible that a client send a message to server specifying another client ID, and the server sending it to the other clients using sessions.
The moment you have a client listening for websockets (which you have to do in other to communicate), it becomes a server.