PM2 for process management in Express - Mini Project: Build & Apply

PM2 for process management with Express

📖 Scenario: You are building a simple Express server to serve a welcome message. You want to manage this server process efficiently using PM2, a popular process manager for Node.js applications.

🎯 Goal: Create a basic Express server, configure PM2 to manage it, and start the server using PM2 to keep it running smoothly.

📋 What You'll Learn

Create a basic Express server in app.js that listens on port 3000

Add a PM2 ecosystem configuration file ecosystem.config.js to define the app process

Use PM2 commands to start and manage the Express server

Ensure the server responds with 'Hello from Express with PM2!' on the root URL

💡 Why This Matters

🌍 Real World

PM2 is widely used in real projects to keep Node.js servers running smoothly, automatically restarting them if they crash and managing multiple processes easily.

💼 Career

Knowing how to use PM2 with Express is a valuable skill for backend developers and DevOps engineers to ensure reliable server uptime.

1

Create a basic Express server

Create a file app.js and write code to import express, create an app, and set it to listen on port 3000. Add a route for GET / that sends the text 'Hello from Express with PM2!'.

Express

// Your code here to create Express server in app.js

Need a hint?

Use import express from 'express' to import Express. Create the app with express(). Use app.get('/', ...) to handle the root route. Listen on port 3000.

2

Add PM2 ecosystem configuration

Create a file named ecosystem.config.js. Define an export with a apps array containing one app object. Set the name to 'express-app' and the script to 'app.js'.

Express

import express from 'express';
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello from Express with PM2!');
});

app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

// Your code here to create ecosystem.config.js

Need a hint?

Use export default to export the config. Inside apps array, add an object with name and script properties.

3

Start the Express app using PM2

Write the PM2 command to start the app using the ecosystem config file ecosystem.config.js. Use the command pm2 start ecosystem.config.js.

Express

import express from 'express';
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello from Express with PM2!');
});

app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

// ecosystem.config.js
export default {
  apps: [
    {
      name: 'express-app',
      script: 'app.js'
    }
  ]
};

// Your code here to start PM2 process

Need a hint?

Use the terminal command pm2 start ecosystem.config.js to start the app with PM2.

4

Manage the Express app with PM2

Write the PM2 command to list all running processes. Use pm2 list to see the status of your Express app.

Express

import express from 'express';
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello from Express with PM2!');
});

app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

// ecosystem.config.js
export default {
  apps: [
    {
      name: 'express-app',
      script: 'app.js'
    }
  ]
};

// PM2 start command
// pm2 start ecosystem.config.js

// Your code here to list PM2 processes

Need a hint?

Use the terminal command pm2 list to view all running PM2 processes.