Following the official node documentation of net and child_process modules, I archived this: a server that spawns a child and connect through net module. But the connection is intermittent. The code is self explanatory, but I've add details in the code comments:
// server.js
const childProcess = require('child_process').fork('child.js');
const server = require('net').createServer((socket) => {
console.log('got socket connection'); // this callback is intermitent
socket.on('data', (stream) => {
console.log(stream.toString());
})
});
server.on('connection', () => {
console.log('someone connected to server'); // this is running only if the code above runs (but its intermitent)
});
server.on('listening', () => {
console.log('server is listening'); // this is the first log to execute
childProcess.send('server', server); // send the server connection to forked child
});
server.listen(null, function () {
console.log('server listen callback'); // this is the second log to execute
});
// child.js
console.log('forked'); // this is the third log to execute
const net = require('net');
process.on('message', (m, server) => {
if (m === 'server') {
const socket = net.connect(server.address());
socket.on('ready', () => {
console.log('child is ready'); // this is the fourth log to execute
socket.write('child first message'); // this is always running
})
}
});
the expected log when execute node server is:
server is listening
server listen callback
forked
child is ready
got socket connection
someone connected to server
child first message
but as the socket callback (at createServer) is intermitent, we get this 50% of times:
server is listening
server listen callback
forked
child is ready
IDK what to do anymore, already tried everything I could... What am I doing wrong?
Just found what was the problem... when I read the documentation I misunderstood that literally the net server is being sent to the child process to share the "connections" to divide the processing in more than one process, and what I was trying to archive was just an 2 way communication with the forked child. I'll let this answer here if someone arrive at the same problem as me. This is the final code:
// server.js
const childProcess = require('child_process').fork('child.js');
const server = require('net').createServer((socket) => {
console.log('got socket connection');
socket.on('data', (stream) => {
console.log(stream.toString());
})
});
server.on('connection', () => {
console.log('someone connected to server');
});
server.listen(null, function () {
childProcess.send(server.address());
});
// child.js
console.log('forked');
const net = require('net');
process.on('message', (message) => {
if (message.port) {
const socket = net.connect(message);
socket.on('ready', () => {
console.log('child is ready');
socket.write('child first message');
})
}
});