Why API Gateway matters in AWS - See It in Action

Why API Gateway matters

📖 Scenario: You are building a simple web service that multiple clients will use. You want to control how clients access your backend services securely and efficiently.

🎯 Goal: Build a basic AWS API Gateway setup that routes requests to a backend Lambda function, demonstrating how API Gateway manages and protects your APIs.

📋 What You'll Learn

Create an AWS Lambda function named hello_lambda that returns a simple greeting.

Create an API Gateway REST API named hello_api.

Configure a resource /hello with a GET method in the API Gateway.

Integrate the GET method with the hello_lambda function.

Enable API Gateway to handle client requests and forward them to Lambda.

💡 Why This Matters

🌍 Real World

API Gateway is used to securely expose backend services like Lambda functions to the internet, controlling access, managing traffic, and enabling monitoring.

💼 Career

Understanding API Gateway is essential for cloud architects and developers building scalable and secure serverless applications on AWS.

1

Create the AWS Lambda function

Create an AWS Lambda function named hello_lambda with a handler that returns the JSON response {"message": "Hello from Lambda!"}.

AWS

# Create the Lambda function hello_lambda with the specified response
# Your code here

Need a hint?

Use a Python function named lambda_handler that returns a dictionary with statusCode and body keys.

2

Create the API Gateway REST API

Create an API Gateway REST API named hello_api and add a resource path /hello.

AWS

import json

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

# Create API Gateway REST API hello_api with resource /hello
# Your code here

Need a hint?

Define a dictionary named hello_api with a key resources containing the path /hello.

3

Add GET method and integrate with Lambda

Add a GET method to the /hello resource in hello_api and integrate it with the hello_lambda function.

AWS

import json

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

hello_api = {
    'name': 'hello_api',
    'resources': {
        '/hello': {}
    }
}

# Add GET method to /hello and integrate with hello_lambda
# Your code here

Need a hint?

Inside the /hello resource, add a GET key with an integration pointing to hello_lambda.

4

Enable API Gateway to handle requests

Add a configuration to hello_api to enable it to handle client requests and forward them to the Lambda function.

AWS

import json

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

hello_api = {
    'name': 'hello_api',
    'resources': {
        '/hello': {
            'GET': {
                'integration': 'hello_lambda'
            }
        }
    }
}

# Enable API Gateway to handle requests
# Your code here

Need a hint?

Add an enabled key set to True in the hello_api dictionary.