Deploying a Number-Classification Flask_CORS API Using Lambda Function

isaac igwe — Thu, 06 Feb 2025 09:26:46 +0000

Summing-Up

Number Classification API is just a simple HTTP API gateway that allows number classification based on mathematical properties provided. This API can be publicly accessible using AWS Lambda or other Cloud platform with a well configured API Gateway. Lambda Function and API Gateway is serverless that is scalable and cost-efficient to deploy a simple module.

Technology Stack:

CORS is enabled for public accessibility.
JSONIFY based reponse.
Logic that determines if a number is prime, even, and odd.
Accept multiple number classification in a single request.

Designed Workflow

Resources Used

AWS Lambda
API Gateway
Python
GitHub

Set Up Instructions

Create and Activate Virtual Environment

python -m venv venv
Source venv\Scripts\activate

Install dependencies

pip install flask flask-cors

python
Downloading Flask_Cors-5.0.0-py2.py3-none-any.whl.metadata (5.5 kB)
Requirement already satisfied: Flask>=0.9 in c:\users\hp\appdata\local\programs\python\python313\lib\site-packages (from flask-cors) (3.1.0)
Requirement already satisfied: Werkzeug>=3.1 in c:\users\hp\appdata\local\programs\python\python313\lib\site-packages (from Flask>=0.9->flask-cors) (3.1.3)
Requirement already satisfied: Jinja2>=3.1.2 in c:\users\hp\appdata\local\programs\python\python313\lib\site-packages (from Flask>=0.9->flask-cors) (3.1.5)
Requirement already satisfied: itsdangerous>=2.2 in c:\users\hp\appdata\local\programs\python\python313\lib\site-packages (from Flask>=0.9->flask-cors) (2.2.0)
Requirement already satisfied: click>=8.1.3 in c:\users\hp\appdata\local\programs\python\python313\lib\site-packages (from Flask>=0.9->flask-cors) (8.1.8)
Requirement already satisfied: blinker>=1.9 in c:\users\hp\appdata\local\programs\python\python313\lib\site-packages (from Flask>=0.9->flask-cors) (1.9.0)
Requirement already satisfied: colorama in c:\users\hp\appdata\local\programs\python\python313\lib\site-packages (from click>=8.1.3->Flask>=0.9->flask-cors) (0.4.6)
Requirement already satisfied: MarkupSafe>=2.0 in c:\users\hp\appdata\local\programs\python\python313\lib\site-packages (from Jinja2>=3.1.2->Flask>=0.9->flask-cors) (3.0.2)
Downloading Flask_Cors-5.0.0-py2.py3-none-any.whl (14 kB)
Installing collected packages: flask-cors
Successfully installed flask-cors-5.0.0

Creating the Flask App

from flask import Flask, request, jsonify
from flask_cors import CORS

app = Flask(_name_)
CORS(app)  # Enable CORS

def is_prime(n):
    """Check if integer n is a prime"""
    if n < 2:
        return False
    if n == 2:
        return True
    if n % 2 == 0:
        return False
    for i in range(3, int(n ** 0.5) + 1, 2):
        if n % i == 0:
            return False
    return True

def is_perfect(n):
    """Check if integer n is a perfect number"""
    if n < 2:
        return False
    total = 1
    for i in range(2, n):
        if n % i == 0:
            total += i
            if total > n:
                return False
        if total == n:
            return True
    return False

def is_armstrong(n):
    """Check if integer n is an Armstrong number"""
    digits = [int(d) for d in str(n)]
    return n==sum(d ** len(digits) for d in digits)

def get_fun_fact(n):
    """Get fun fact about integer n"""
    if is_prime(n):
        return f"{n} is a prime number because it has only two division: 1 and itself."
    if is_perfect(n):
        return f"{n} is a prime number because the sum of its proper diisors equals the number."
    if is_armstrong(n):
        return f"{n} is an Armstrong number because {'+'.join([f'{d}^{len(str(n))}' for d in str(n)])} = {n}."
    else:
        return f"{n} is just an interesting number!"


@app.route('/api/classify-number', methods=['GET'])
def classify_number():
    num = request.args.get('number')

    if not num or not num.isdigit():
        return jsonify({"number": num, "error": True}), 400

    num = int(num)

    response = {
        "number": num,
        "is_prime": is_prime(num),
        "is_perfect": is_perfect(num),
        "properties": ["odd" if num % 2 else "even"],
        "digit_sum": sum(int(d) for d in str(num)),
        "fun_fact": get_fun_fact(num)
    }

    if is_armstrong(num):
        response["properties"].append("armstrong")

    return jsonify(response)

if _name_ == '_main_':
    app.run(debug=True)

API Deployed Locally

Documents/Devops/HNG Project/stage 1/API/main.py"
 * Serving Flask app 'main'
 * Debug mode: on
 * Debug mode: on
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.        
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.        
 * Running on http://127.0.0.1:5000
Press CTRL+C to quit
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 934-514-253
127.0.0.1 - - [05/Feb/2025 01:40:38] "GET /api/classify-number?number=153 HTTP/1.1" 200 -
127.0.0.1 - - [05/Feb/2025 01:41:30] "GET /api/classify-number?number=153 HTTP/1.1" 200 -
127.0.0.1 - - [05/Feb/2025 08:25:31] "GET /api/classify-number?number=153 HTTP/1.1" 200

Test API Locally:

http://127.0.0.1:5000/api/classify-number?number=153

JSON Response

{
  "digit_sum": 9,
  "fun_fact": "153 is an Armstrong number because 1^3+5^3+3^3 = 153.",
  "is_perfect": false,
  "is_prime": false,
  "number": 153,
  "properties": [
    "odd",
    "armstrong"
  ]
}

Deploy API on Lambda Environment

import json

def is_prime(n):
    if n < 2:
        return False
    for i in range(2, int(n ** 0.5) + 1):
        if n % i == 0:
            return False
    return True

def is_perfect(n):
    if n <= 0:
        return False  # Fix: 0 should not be a perfect number
    return n == sum(i for i in range(1, n) if n % i == 0)

def is_armstrong(n):
    digits = [int(d) for d in str(abs(n))]  # Use absolute value to avoid issues
    power = len(digits)
    return n == sum(d**power for d in digits)

def get_fun_fact(n):
    """Get fun fact about integer n"""
    if is_prime(n):
        return f"{n} is a prime number because it has only two division: 1 and itself."
    if is_perfect(n):
        return f"{n} is a prime number because the sum of its proper diisors equals the number."
    if is_armstrong(n):
        return f"{n} is an Armstrong number because {'+'.join([f'{d}^{len(str(n))}' for d in str(n)])} = {n}."
    else:
        return f"{n} is just an interesting number!"

def lambda_handler(event, context):
    try:
        query_params = event.get("queryStringParameters", {})
        num_str = query_params.get("number", "")

        # Validate input: number must be a valid integer or float
        try:
            num = float(num_str) if "." in num_str else int(num_str)
        except ValueError:
            return {
                "statusCode": 400,
                "headers": {
                    "Content-Type": "application/json",
                    "Access-Control-Allow-Origin": "*"
                },
                "body": json.dumps({"number": num_str, "error": True})
            }

        # Construct response data
        response = {
            "number": num,
            "is_prime": is_prime(int(num)),  # Convert to int for prime check
            "is_perfect": is_perfect(int(num)),  # Convert to int for perfect check
            "properties": ["odd" if int(num) % 2 else "even"],
            "digit_sum": sum(int(d) for d in str(abs(int(num)))),
            "fun_fact": get_fun_fact(int(num))
        }

        if is_armstrong(int(num)):
            response["properties"].append("armstrong")

        return {
            "statusCode": 200,
            "headers": {
                "Content-Type": "application/json",
                "Access-Control-Allow-Origin": "*"
            },
            "body": json.dumps(response)
        }

    except Exception as e:
        return {
            "statusCode": 500,
            "headers": {
                "Content-Type": "application/json",
                "Access-Control-Allow-Origin": "*"
            },
            "body": json.dumps({"error": str(e)})
        }

Create an API Gateway

Choose HTTP API.
Add Integration - Choose Lambda Function.
Select your Lambda function (Number_Classification).
Enter /api/classify-number as the route.
Choose GET as the method.
Then Deploy

API Test

Copy the invoke URL and past on the browser.

https://x71n6tgymk.execute-api.us-east-1.amazonaws.com/test/api/classify-number?number=371

JSON Response

 "digit_sum": 9,
  "fun_fact": "153 is an Armstrong number because 1^3+5^3+3^3 = 153.",
  "is_perfect": false,
  "is_prime": false,
  "number": 153,
  "properties": [
    "odd",
    "armstrong"
  ]

Enabling CORS in API Gateway

Skills Achieved

Deploy Lambda Function using HTTP API.
Configure CORS for public API access.
Handling API requests and responses in JSON format.
Write Logic that determines if a number is prime, even, and odd with python

Deploy NGINX Web Server on AWS EC2 Ubuntu Server. DevOps HNG12 Stage 0 Task

isaac igwe — Fri, 31 Jan 2025 12:37:22 +0000

Introduction

Cloud Computing is a fundamental skill for DevOps professionals. This document outlines the steps I took to install and configure an NGINX web server on an AWS EC2 instance with an Ubuntu image installed. The goal here is to deploy a functional web server on AWS cloud infrastructure.

Project Setup
Deploy AWS EC2 Instance

My instance name: My Nginx Server
AMI: Ubuntu Server 24.04
Instance Type: t2 micro
Key pair: nginx-web-key
SG: Allow SSH traffic from 0.0.0.0/0

Connect to the EC2 instance

Connect to the EC2 instance using the EC2 CMD and run sudo apt update to update the package list.

Run Sudo apt install nginx -y to install the Nginx package.

Start and enable Nginx on the web server

Configure the html page, run sudo nano /var/www/html/index.html
Edit the html contant
Save and exit.

Restart and check the status of the Nginx package.

Status output

Open a web browser, then copy and paste the EC2 public URL.

Challenge Faced. My web page was not reachable until I opened the web page with Chrome incognito browser, that was when I was able to view the page.

Objective of this task to my DevOps Career

This task installs the fundamental knowledge required for cloud computing and DevOps roles.

upon completion of this task, i have gained:

Learn how to deploy and secure a web server.
Understand the AWS cloud infrastructure and resource management.
Understand the troubleshooting skills for common server deployment.

Conclusion

As a beginner in achieving this stage 0 task, I was excited after completing this project.

References

DevOps Engineers
Cloud Engineers
Platform Engineers
Kubernetes Specialists
AWS Solutions Architects
Azure DevOps Engineers
Google Cloud Engineers
CI/CD Pipeline Engineers
Monitoring/Observability Engineers
Automation Engineers
Docker Specialists
Linux Developers

DEV Community: isaac igwe

Deploying a Number-Classification Flask_CORS API Using Lambda Function

Summing-Up

Technology Stack:

Designed Workflow

Resources Used

Set Up Instructions

Create and Activate Virtual Environment

Install dependencies

Creating the Flask App

API Deployed Locally

Test API Locally:

JSON Response

Deploy API on Lambda Environment

Create an API Gateway

API Test

Enabling CORS in API Gateway

Skills Achieved

Deploy NGINX Web Server on AWS EC2 Ubuntu Server. DevOps HNG12 Stage 0 Task

Introduction

Objective of this task to my DevOps Career

Conclusion

References