Is it possible connect to socket.io server with standard web-socket client?
When connecting to socket.io server through socket.io client, Url started with HTTP but for web-socket clients must use ws.
so, if it is possible, how to connect to socket.io server and what is the url for connecting to socket.io server?
socket.io has a protocol on top of webSockets. If you're going to use socket.io on the server side, then you have to use a socket.io-compatible client on the other end.
So, you can't use a plain webSocket client to connect to a socket.io server.
The socket.io protocol is here.
Related
I'm new in socket-io. socket-io working fine but keep sending connect request infinitely to server.
Here is my client ts :
private url = environment.socketServer;
constructor() { this.socket = io(this.url) }
The usual reason for a socket.io client to try to connect over and over is if the socket.io version on the server and client are not compatible. The client connects, the server finds the version is incompatible and drops the connection and the client then tries to connect again, over and over.
Other possible issues:
Server infrastructure (such as load balancers, proxies, firewalls, etc...) are not properly configured to allow webSocket connections.
You're trying to connect to a cluster, but it isn't configured for sticky connections that will "bind" a socket.io client to the same server.
You're confused about how a socket.io connection starts. It is normal for the client to start with a couple web connections in a row (polling) until it realizes that both sides support a webSocket and then socket.io switches over to webSocket.
Is it possible to fetch NodeJS Socket server from web browser ?
I've create net server and i would like request this server from web client :
const server = net.createServer();
server.listen(SERVER_PORT);
I've try to fetch with ip and port, but no result.
Anyone have idea ?
This is not possible.
From web browser, you can only communicate through HTTP or WebSocket.
If you try to talk to a TCP server with the wrong protocol, it'll error out.
If you absolutly want your server to be a net TCP server, you can implement a server that communicate with your web app through a WebSocket and forward messages to your net server.
Otherwise, you could just do a WebSocket server, with socket.io for example.
Hope it helps,
regards
I am trying to create a multi room chat application in node.js using socket.io and express. I am confused between use of server port and websocket port. I understand server port is used by the client to connect to server. But not sure about use of websocket port.
Thanks & Regards..
webSockets can share the same port as your web server and this is a common configuration. The reason this works is because of how a webSocket establishes a connection (all webSocket connections are initiated with an HTTP request). It works like this:
Client makes an HTTP request to a web server with a header specifying that they want to "upgrade" to the webSocket protocol and sends a security-related header.
Web server sees the upgrade request and, if it has support enabled for webSocket connections, it will respond with a 101 request (switching protocols) and another security related header.
Client gets the accepted upgrade and both ends switch to the webSocket protocol and the original TCP socket that started out using the HTTP protocol is now using the webSocket protocol.
In this manner, the same port and webServer can be used for regular HTTP requests or webSocket connection requests.
For a chat application it is common to use a webSocket connection because it is a continuous connection that more easily allows the server to send information directly to the client which is often needed in a chat application.
To understand more about how a webSocket connection and server work, see this reference on MDN: Writing WebSocket servers which shows the step by step process for initiating a webSocket connection.
Server socket is used by server... that keeps listening to coming sockets request in a loop... and websocket sends a request to server socket and bound a connection between two devices...
If you have / want to have web clients, WebSocket is going to be required, because there is no access to 'regular' TCP (or UDP) sockets from browser-based JavaScript (and I assume you do not want Flash, SilverLight or Java Applets, in 2017). WebSocket is not special because of the port number, but it is special because of the protocol: a WebSocket connection starts as a regular HTTP connection, and protocol upgrade reconfigures it afterwards, it is designed for the browser-world, and even capable of traversing HTTP proxies. After establishing the connection, it provides a full-duplex, bi-directional message stream, very usable for chat applications.
And because of being a Web-thing, you could simply use port 80, if you are allowed to.
I'm developing a socket.io Server in Node.js. To test it, I am developing a set of integration tests using Jest. Each test establishes a connection to my local Socket.io Server, however, I am unable to require that the transport is 'websocket'.
I know that my Socket.io Server supports the websocket transport, as it I demonstrate when the browser connects to it.
Is there anything different about running the socket.io Client in Node.js that prevents the 'websocket' transport from being used?
As socket.io said, it supports WebSocket, so, I use HTML5 standard web socket api to access socket.io server, but I always get below error:
WebSocket connection to 'ws://localhost:8080/' failed: Connection
closed before receiving a handshake response
Then, I tried to use socket.io client in js to access socket.io server, it works, and by chrome network monitoring, i found it using web socket protocol correctly.
Did anyone ever try W3C Websocket api to access socket.io server and met similar issue? or any ideas or clues for my problem? appreciated!
Test code is here: https://github.com/piginzoo/socketiotest
Note: Socket.IO is not a WebSocket implementation. Although Socket.IO indeed uses WebSocket as a transport when possible, it adds some metadata to each packet: the packet type, the namespace and the ack id when a message acknowledgement is needed. That is why a WebSocket client will not be able to successfully connect to a Socket.IO server, and a Socket.IO client will not be able to connect to a WebSocket server (like ws://echo.websocket.org) either.
And I find this in socketio github issues:
Socket.IO is not a WebSocket server. Please see ws instead.
https://github.com/socketio/socket.io/issues/3022
The error message you got was because you used the wrong url. The error message "Connection closed before receiving a handshake response" actually told you this (not receiving a response)
It should be 'ws://localhost:8080/socket.io/?EIO=3&transport=websocket'
Check here https://socket.io/docs/client-api/#With-custom-path & https://socket.io/docs/internals/ for details
e.g.
"EIO=3" # the current version of the Engine.IO protocol
BUT as other answer said and actually that was what socket.io readme said
Although Socket.IO indeed uses WebSocket as a transport when possible, it adds some metadata to each packet: the packet type, the namespace and the ack id when a message acknowledgement is needed. That is why a WebSocket client will not be able to successfully connect to a Socket.IO server, and a Socket.IO client will not be able to connect to a WebSocket server.
I have tested that to verify both ws & browser native Websocket can't not connect to a Socket.IO server. They are both immediately disconnected from Socket.IO server after they connects, with Socket.IO server send out the error message socket id xxx has disconnected with reason parse error
The ws author also mentioned here https://github.com/websockets/ws/issues/1390
using plain WebSocket to talk with a Socket.IO server does not work seamlessly.
If you want to use browser native Websocket you can use ws can server.
We had exactly the same problem. Ended up with ws websockets. Not sure may be there is better solution.