What is an API?

API (Application Programming Interface) is a set of rules and protocols that allows different software applications to communicate with each other. It serves as an intermediary between applications, enabling them to exchange data and perform functions. APIs are widely used for integrating systems, enabling third-party developers to interact with a service, and exposing functionality in a standardized way.

API Management

API Management involves the creation, publication, monitoring, and management of APIs in a secure and scalable manner. It ensures APIs are reliable, available, and secure. Key aspects include:

• Authentication and Authorization: Ensuring only authorized users can access the API.
• Rate Limiting: Restricting the number of requests to prevent misuse.
• Analytics and Monitoring: Tracking usage metrics, performance, and errors.
• Documentation: Providing developers with clear guidance on how to use the API.
• Versioning: Managing different versions of an API to ensure backward compatibility.

Task: Create a Simple REST API using Flask and Deploy it on AWS

Step 1: Set up Flask and Create the API

1. Install Flask:

   pip install flask

1. Write a Simple REST API: Create a file named app.py:

   from flask import Flask, jsonify, request

   app = Flask(__name__)

   # Sample data
   users = [
       {"id": 1, "name": "John Doe"},
       {"id": 2, "name": "Jane Doe"}
   ]

   # Get all users
   @app.route('/users', methods=['GET'])
   def get_users():
       return jsonify(users)

   # Get a single user by ID
   @app.route('/users/<int:user_id>', methods=['GET'])
   def get_user(user_id):
       user = next((user for user in users if user["id"] == user_id), None)
       return jsonify(user) if user else ("User not found", 404)

   # Add a new user
   @app.route('/users', methods=['POST'])
   def add_user():
       new_user = request.get_json()
       users.append(new_user)
       return jsonify(new_user), 201

   if __name__ == '__main__':
       app.run(debug=True)

1. Test the API Locally: Run the API:

   python app.py

Access it at http://127.0.0.1:5000/users.

Step 2: Prepare for AWS Deployment

1. Install gunicorn (for production-grade deployment):

   pip install gunicorn

1. Create a requirements.txt: Generate a list of dependencies:

   pip freeze > requirements.txt

1. Add a WSGI Entry Point: Create a file wsgi.py:

   from app import app

   if __name__ == "__main__":
       app.run()

Step 3: Deploy on AWS

1. Launch an EC2 Instance:

   • Select an Amazon Linux or Ubuntu instance.
   • Open ports 22 (SSH) and 5000 (or your desired API port) in the security group.

2. Install Required Packages on EC2:
   

   sudo yum update -y  # or apt-get update for Ubuntu
   sudo yum install python3-pip -y

1. Upload Your Application: SCP or use AWS CLI to transfer files to the instance:

   scp -i your-key.pem app.py requirements.txt wsgi.py ec2-user@<EC2-IP>:~/

1. Install Dependencies:

   pip3 install -r requirements.txt

1. Run the API Using Gunicorn:

   gunicorn --bind 0.0.0.0:5000 wsgi:app

1. Access Your API: Visit http://<EC2-Public-IP>:5000/users.

Optional: Use AWS Elastic Beanstalk

To automate deployment, you can package your Flask application and deploy it using AWS Elastic Beanstalk for a fully managed environment.