Serverless API for Hotel Data: Using API Gateway, Lambda, and DynamoDB

This project demonstrates the creation of a serverless API for managing hotel data using AWS services: API Gateway, Lambda, and DynamoDB.

Components

• DynamoDB: Backend database for storing hotel booking data.
• Lambda: Acts as the web server to process requests.
• API Gateway: Serves as the frontend to handle API requests and route them to Lambda.

Project Workflow

When a customer accesses the application, the request is sent to API Gateway. API Gateway then forwards the request to a Lambda function, which processes the information entered by the customer and stores it in the DynamoDB table.

Steps to Create the Project

1. Create IAM Role for Lambda Function

• Create an IAM role that allows the Lambda function to write data to the DynamoDB table.
• Attach the following policies to the IAM role:
  • AWSLambdaBasicExecutionRole: Provides permissions to write logs.
  • AmazonDynamoDBFullAccess: Allows full access to DynamoDB.

2. Create Lambda Function

• Create a Lambda function named karanfn.
• Attach the IAM role created in the previous step.
• Upload the following files to the Lambda function:
  • lambda_function.py: Contains the Python code to handle POST requests, interact with DynamoDB, and generate HTML responses for GET requests.
  • contactus.html: Frontend HTML code for the hotel booking form.
  • success.html: HTML code for the success page displayed after a successful booking.

3. Create DynamoDB Table

• Create a DynamoDB table named karantable.
• Set aadhar as the primary key.

4. Configure API Gateway

• Create a new REST API for complete control over request and response handling.
• Add two methods:
  • GET: For serving the HTML form.
  • POST: For handling form submissions.
• Configure both methods to use the Lambda function karanfn.
• Enable CORS for both methods to handle cross-origin requests.
• Deploy the API and obtain the invoke URL.

CORS Configuration

• Enable CORS on the API Gateway methods:
  • In the API Gateway console, go to the Stages section and select your deployment stage.
  • For each method (GET and POST), configure CORS headers in the Method Response and Integration Response sections.

Deploy and Test

• Deploy the API Gateway.
• Test the GET request to ensure the HTML form is served correctly.
• Test the POST request to ensure data is correctly written to the DynamoDB table.

Invoke URL

The deployed API can be accessed at:

• https://giu9eobrzc.execute-api.ap-south-1.amazonaws.com/dev

Summary

This project showcases a serverless architecture using AWS services to create an API for hotel data management. It leverages API Gateway for frontend handling, Lambda for processing requests, and DynamoDB for data storage, providing a scalable and efficient solution for hotel booking systems.