REST API creation in AWS - Mini Project: Build & Apply

REST API creation

📖 Scenario: You are building a simple REST API using AWS API Gateway and AWS Lambda. This API will respond to HTTP GET requests with a welcome message.

🎯 Goal: Create a REST API in AWS API Gateway with a GET method linked to a Lambda function that returns a welcome message.

📋 What You'll Learn

Create a Lambda function named WelcomeFunction with a basic handler.

Create an API Gateway REST API named WelcomeAPI.

Add a resource /welcome to the API.

Add a GET method to the /welcome resource linked to the Lambda function.

Deploy the API to a stage named prod.

💡 Why This Matters

🌍 Real World

REST APIs are commonly used to expose backend services to web and mobile applications. AWS API Gateway and Lambda provide a serverless way to build scalable APIs.

💼 Career

Understanding how to create and deploy REST APIs on AWS is a key skill for cloud engineers, backend developers, and DevOps professionals.

1

Create the Lambda function

Create a Lambda function named WelcomeFunction with a handler that returns a JSON response with status code 200 and body 'Welcome to the API!'. Use Python 3.12 runtime.

AWS

# Your code here to create WelcomeFunction Lambda

Need a hint?

Define the Lambda function resource with the correct runtime and handler. Also create an IAM role with Lambda execution permissions.

2

Create the API Gateway REST API and resource

Create an API Gateway REST API named WelcomeAPI. Add a resource with path part welcome to this API.

AWS

resource "aws_lambda_rest_api" "WelcomeAPI" {
  # Your code here to create WelcomeAPI
}

resource "aws_api_gateway_resource" "welcome_resource" {
  # Your code here to add /welcome resource
}

Need a hint?

Define the API Gateway REST API resource and add a child resource with path part 'welcome'.

3

Add GET method linked to Lambda

Add a GET method to the /welcome resource. Integrate this method with the Lambda function WelcomeFunction using AWS_PROXY integration.

AWS

resource "aws_api_gateway_method" "get_welcome" {
  # Your code here to add GET method
}

resource "aws_api_gateway_integration" "lambda_integration" {
  # Your code here to link GET method to Lambda
}

Need a hint?

Add the GET method resource and integrate it with the Lambda function using AWS_PROXY.

4

Deploy the API to prod stage

Create a deployment for the API Gateway REST API WelcomeAPI and deploy it to a stage named prod.

AWS

resource "aws_api_gateway_deployment" "WelcomeAPI_deployment" {
  # Your code here to deploy WelcomeAPI
}

resource "aws_api_gateway_stage" "prod_stage" {
  # Your code here to create prod stage
}

Need a hint?

Create a deployment resource and a prod stage resource for the API Gateway REST API.