AWS API Gateway

What is AWS API Gateway?

AWS API Gateway is a fully managed service that allows developers to create, deploy, and manage secure REST, HTTP, and WebSocket APIs at any scale.

Why Use API Gateway?

  • Handles API traffic efficiently with **throttling & caching**.
  • Provides **authentication and authorization** with IAM and JWT tokens.
  • Supports **serverless applications** by integrating with AWS Lambda.
  • Monitors API performance with **CloudWatch logs**.

API Gateway Components

  • REST API - Standard APIs following HTTP methods.
  • HTTP API - Lightweight, low-latency alternative to REST APIs.
  • WebSocket API - Real-time two-way communication.
  • Stages - Different versions of the API (dev, prod).

Creating an API Gateway

Follow these steps to create an API Gateway:

  1. Go to AWS Console → API Gateway.
  2. Choose "Create API" and select "REST API".
  3. Define the API methods (GET, POST, PUT, DELETE).
  4. Integrate it with AWS Lambda, DynamoDB, or an HTTP endpoint.
  5. Deploy the API and test it using the generated URL.

Example: API Gateway with Lambda

Here’s an example of setting up an API Gateway with a Lambda function.


import json

def lambda_handler(event, context):
    return {
        'statusCode': 200,
        'body': json.dumps('Hello from API Gateway!')
    }

Steps:

  • Create a **Lambda function** with the above code.
  • In API Gateway, create a new **REST API**.
  • Define a **GET method** and integrate it with the Lambda function.
  • Deploy the API and invoke it using the generated **API URL**.

Securing API Gateway

  • IAM Authentication - Secure access using AWS IAM roles.
  • JWT Tokens - Use Amazon Cognito for token-based authentication.
  • Throttling - Limit API requests to prevent abuse.

Monitoring API Gateway

Use **AWS CloudWatch** to track API calls, latency, and errors.


aws apigateway get-metrics --rest-api-id API_ID

Conclusion

AWS API Gateway is a powerful tool for managing APIs, providing security, scalability, and monitoring. It works seamlessly with AWS services like Lambda, DynamoDB, and IAM for authentication.