Index.ts

import * as cluster from "cluster";
import { cpus } from "os";
import { env } from "process";
import { config } from "./config";
import { Server } from "./config/Server";

if (cluster.isMaster) {

    console.log(`\n -------------------> RUN ${env.NODE_ENV} ENVIRONMENT \n`);

    for (const cpu of cpus()) {
        cluster.fork();
    }

    cluster.on("exit", (worker, code, signal) => {
        console.log("Worker " + worker.process.pid + " died with code: " + code + ", and signal: " + signal);
        console.log("Starting a new worker");
        cluster.fork();
    });

} else {

    const port: number = Number(env.PORT) || config.PORT_APP || 3000;

    new Server().Start().then((server) => {

        server.listen(port);

        server.on("error", (error: any) => {
            if (error.syscall !== "listen") {
                throw error;
            }

            switch (error.code) {
                case "EACCES":
                    console.error("Port requires elevated privileges");
                    process.exit(1);
                    break;
                case "EADDRINUSE":
                    console.error("Port is already in use");
                    process.exit(1);
                    break;
                default:
                    throw error;
            }
        });

        server.on("listening", () => {
            console.log("Server is running in process " + process.pid + " listening on PORT " + port + "\n");
        });

    });

}