In this exercise, we will deploy a simple web application using a Platform as a Service (PaaS) provider. This hands-on activity will help you understand the deployment process and the benefits of using PaaS for web applications.

• Understand the steps involved in deploying a web application using a PaaS provider.
• Gain practical experience with a popular PaaS platform.
• Learn how to manage and scale a web application on a PaaS platform.

• Basic understanding of web applications.
• Familiarity with Git and command-line interface (CLI).
• An account with a PaaS provider (e.g., Heroku, AWS Elastic Beanstalk, Google App Engine).

1. Install Git: Ensure that Git is installed on your machine. You can download it from git-scm.com.

2. Install Heroku CLI: For this exercise, we will use Heroku as our PaaS provider. Download and install the Heroku CLI from Heroku CLI.

We will create a simple Node.js application for this exercise. Follow the steps below:

1. Initialize a New Node.js Project:

   mkdir my-web-app
   cd my-web-app
   npm init -y
   

2. Install Express:

   npm install express
   

3. Create index.js File:

   const express = require('express');
   const app = express();
   const port = process.env.PORT || 3000;
   
   app.get('/', (req, res) => {
       res.send('Hello, World!');
   });
   
   app.listen(port, () => {
       console.log(`App running on port ${port}`);
   });
   

4. Update package.json: Add a start script in the scripts section of your package.json file:

   "scripts": {
       "start": "node index.js"
   }
   

1. Log In to Heroku:

   heroku login
   

2. Create a New Heroku App:

   heroku create
   

3. Initialize a Git Repository:

   git init
   git add .
   git commit -m "Initial commit"
   

4. Deploy to Heroku:

   git push heroku master
   

5. Open the Deployed Application:

   heroku open
   

1. View Logs:

   heroku logs --tail
   

2. Scale the Application:

   heroku ps:scale web=1
   

1. Create a New Web Application:

   • Follow the steps in the guide to create a simple Node.js web application.
   • Ensure your application runs locally before proceeding to deployment.

2. Deploy the Application to Heroku:

   • Use the Heroku CLI to create a new app and deploy your web application.
   • Verify that your application is accessible via the Heroku URL.

3. Manage and Scale the Application:

   • Use Heroku CLI commands to view logs and scale your application.
   • Experiment with scaling the application up and down.

1. Creating the Web Application:

   • Follow the code snippets and commands provided in the guide to set up your Node.js application.

2. Deploying to Heroku:

   • Ensure you have committed your code to a Git repository.
   • Use git push heroku master to deploy your application.
   • Open the application using heroku open to verify deployment.

3. Managing and Scaling:

   • Use heroku logs --tail to monitor your application logs.
   • Scale your application using heroku ps:scale web=1.

• Missing Dependencies: Ensure all dependencies are listed in package.json and installed using npm install.
• Port Configuration: Use process.env.PORT to allow Heroku to assign the port dynamically.
• Git Configuration: Ensure your local repository is correctly set up and connected to Heroku.

In this exercise, you have successfully deployed a simple web application using Heroku, a popular PaaS provider. You have learned how to set up a development environment, create a web application, deploy it to a PaaS platform, and manage and scale the application. This practical experience will be valuable as you explore more complex applications and other PaaS providers.