How to set up a socket connection on a strapi server - socket.io

Question

I am trying to integrate socket.io with strapi. But unfortunately I have been unable to do so without any proper tutorial or documentation covering this aspect.
I followed along with the only resource I found online which is:
https://medium.com/strapi/strapi-socket-io-a9c856e915a6
But I think the article is outdated. I can't seem to run the code mentioned in it without running into tonnes of errors.
Below is my attempt to implement it and I have been trying to connect it through a chrome websocket plugin smart websocket client But I am not getting any response when I try to run the server.
I'm totally in the dark. Any help will be appreciated
module.exports = ()=> {
// import socket io
var io = require('socket.io')(strapi.server)
console.log(strapi.server) //undefined
// listen for user connection
io.on('connect', socket => {
socket.send('Hello!');
console.log("idit")
// or with emit() and custom event names
socket.emit('greetings', 'Hey!', { 'ms': 'jane' }, Buffer.from([4, 3, 3, 1]));
// handle the event sent with socket.send()
socket.on('message', (data) => {
console.log(data);
});
// handle the event sent with socket.emit()
socket.on('salutations', (elem1, elem2, elem3) => {
console.log(elem1, elem2, elem3);
});
});
};

Answer 1

So I found the solution. Yay. I'll put it here just in case anybody needs it.
boostrap.js
module.exports = async () => {
process.nextTick(() =>{
var io = require('socket.io')(strapi.server);
io.on('connection', async function(socket) {
console.log(`a user connected`)
// send message on user connection
socket.emit('hello', JSON.stringify({message: await strapi.services.profile.update({"posted_by"})}));
// listen for user diconnect
socket.on('disconnect', () =>{
console.log('a user disconnected')
});
});
strapi.io = io; // register socket io inside strapi main object to use it globally anywhere
})
};
Found this at: https://github.com/strapi/strapi/issues/5869#issuecomment-619508153_
Apparently, socket.server is not available when the server starts. So you have to make use of process.nextTick that waits for the socket.server to initialize.
I'll also add a few questions that I faced when setting this up.
How do i connect from an external client like nuxt,vue or react?
You just have to connect through "http://localhost:1337" that is my usual address for strapi.
I am using nuxt as my client side and this is how set up my socketio on the client side
I first installed nuxt-socket-io through npm
Edited the nuxt.config file as per it's documention
modules:[
...
'nuxt-socket-io',
...
],
io: {
// module options
sockets: [
{
name: 'main',
url: 'http://localhost:1337',
},
],
},
And then i finally added a listener in one of my pages.
created() {
this.socket = this.$nuxtSocket({})
this.socket.on('hello', (msg, cb) => {
console.log('SOCKET HI')
console.log(msg)
})
},
And it works.

Answer 2

A clean way to integrate third-party services into Strapi is to use hooks. They are loaded once during the server boot. In this case, we will create a local hook.
The following example has worked with strapi#3.6.
Create a hook for socket.io at ./hooks/socket.io/index.js
module.exports = strapi => {
return {
async initialize() {
const ioServer = require('socket.io')(strapi.server, {
cors: {
origin: process.env['FRONT_APP_URL'],
methods: ['GET', 'POST'],
/* ...other cors options */
}
})
ioServer.on('connection', function(socket) {
socket.emit('hello', `Welcome ${socket.id}`)
})
/* HANDLE CLIENT SOCKET LOGIC HERE */
// store the server.io instance to global var to use elsewhere
strapi.services.ioServer = ioServer
},
}
}
Enable the new hook in order for Strapi to load it - ./config/hook.js
module.exports = {
settings: {
'socket.io': {
enabled: true,
},
},
};
That's done. You can access the websocket server inside ./config/functions/bootstrap.js or models' lifecycle hooks.
// ./api/employee/models/employee.js
module.exports = {
lifecycles: {
async afterUpdate(result, params, data) {
strapi.services.ioServer.emit('update:employee', result)
},
},
};

Answer 3

For those who are looking the answer using Strapi version 4
var io = require("socket.io")(strapi.server.httpServer)