Git auto deploy script for Express JS with PM2

processes.json

{
    "apps": [
        {
            "name": "Sample App Name",
            "script": "index.js",
            "watch": "./",
            "log_date_format": "YYYY-MM-DD HH:mm Z"
        }
    ]
}

webhook.js

const express = require("express");
const router = express.Router();
const cp = require('child_process');

const gitDir = "/root/apps/app_name";

//Git pull middleware
const doGitPull = (req, res, next) => {
    const pull = cp.spawn('git', ['pull'], { cwd: gitDir })
    pull.stdout.on('data', d => console.log(d.toString()))
    pull.stderr.on('data', e => console.error(e.toString()))
    pull.on('error', e => (
        console.error(e.toString()),
        res.status(500).json({ message: e.toString() })))
    pull.on('exit', code => {
        if (code == 0) next()
        else res.sendStatus(500).json({
            message: code.toString(),
        })
    })
}

router.post("/pull", doGitPull, (req, res) => {
    res.status(200).json({
        message: "Deployed successfully!",
    });
});

module.exports = router;