how to run "npm start" by PM2? - node.js

Question

I have seen many questions here but that was not working for me. That why asking this question?
I am using DigitalOcean Ubuntu 16.04 server. I have a node project run by "npm start".
Script is:
"scripts": {
"start": "node ./bin/www"
}
generally pm2 work for
pm2 start app.js
As my script is like this and run by npm start how can I run my server forever.

Answer 1

You can run built-in npm scripts like this:
pm2 start npm -- start
If you have a custom script, you can run like this:
pm2 start npm -- run custom
--
In your case, pm2 start npm -- start would run node ./bin/www. Change the start script to node app.js if you want to run node app.js.

Answer 2

Yes, you can do it very efficiently by using a pm2 config (json) file with elegance.
package.json file (containing below example scripts)
"scripts": {
"start": "concurrently npm:server npm:dev",
"dev": "react-scripts start",
"build": "node ./scripts/build.js",
"eject": "react-scripts eject",
"lint": "eslint src server",
"shivkumarscript": "ts-node -T -P server/tsconfig.json server/index.ts"
}
Suppose we want to run the script named as 'shivkumarscript' with pm2 utility. So, our pm2 config file should be like below, containing 'script' key with value as 'npm' and 'args' key with value as 'run '. Script name is 'shivkumarscript' in our case.
ecosystem.config.json file
module.exports = {
apps: [
{
name: "NodeServer",
script: "npm",
automation: false,
args: "run shivkumarscript",
env: {
NODE_ENV: "development"
},
env_production: {
NODE_ENV: "production"
}
}
]
}
Assuming that you have already installed Node.js, NPM and PM2 on your machine. Then below should be the command to start the application through pm2 which will in turn run the npm script (command line mentioned in your application's package.json file):
For production environment:
pm2 start ecosystem.config.js --env production --only NodeServer
For development environment:
pm2 start ecosystem.config.js --only NodeServer
...And Boooom! guys

Answer 3

My application is called 'app.js'. I have the exact same start script for an express Node.js application.
And after googling tons this solved my problem, instead of calling pm2 start app.js.
pm2 start ./bin/www

Answer 4

for this first, you need to create a file run.js and paste the below code on that.
const { spawn } = require('child_process');
//here npm.cmd for windows.for others only use npm
const workerProcess = spawn('npm.cmd', ['start']);
workerProcess.stdout.on('data', function (data) {
console.log('stdout: ' + data);
});
workerProcess.stderr.on('data', function (data) {
console.log('stderr: ' + data);
});
workerProcess.on('close', function (code) {
console.log('child process exited with code ' + code);
});
and run this file with pm2.
pm2 start run.js