tcp_server.js

const net = require('net')
const conf = require('./config/config')

const {
    log
} = require('./util/loggerTool')

const server = net.createServer()

// emits when any error occurs
server.on('error', (error) => {
    log("tcp_server", "error", error)
    server.close()
})

const sockets = []
server.on('connection', sock => {
	log("tcp_server", "info", `Connected at ${sock.remoteAddress}:${sock.remotePort}`)

	sockets.push(sock)

	sock.on('data', data => {
		
		log("tcp_server", "info", data.toString() + ` | Received ${sock.bytesRead} bytes from ${sock.remoteAddress}:${sock.remotePort}`)

		let timestp = new Date()
		const response = {
			description: 'TCP PORT TEST BY RMS Math',
			serverPort: conf.port,
			timestamp: timestp.toJSON(),
			received: {
				message: data.toString(),
				fromIP: sock.remoteAddress,
				fromPort: sock.remotePort
			}
		}
		const dataBuffer = Buffer.from(JSON.stringify(response))

		// Write the data back to all the connected, the client will receive it as data from the server
		sockets.forEach((sock, index, array) => {
			sock.write(dataBuffer)	
		})
	})

	// Add a 'close' event handler to this instance of socket
	sock.on('close', data => {
		let index = sockets.findIndex( o => {
			return o.remoteAddress === sock.remoteAddress && o.remotePort === sock.remotePort
		})

		if (index !== -1) { 
			sockets.splice(index, 1) 
		}
		log("tcp_server", "info", `Socket closed with ${sock.remoteAddress}:${sock.remotePort}`)
	})	// end sock.on
})	


// server.listen(conf.port, conf.serverHost, () => {
server.listen(conf.port, conf.serverHost, () => {
	const address = server.address()
	const port = address.port
    const family = address.family
    const ipaddr = address.address
    
	log("tcp_server", "info", 'Server is listening at port ' + port)
    log("tcp_server", "info", 'Server ip :' + ipaddr)
    log("tcp_server", "info", 'Server is IP4/IP6 : ' + family)
})	// server.listen()