An API gateway is an essential component of API management that serves as a bridge between clients and backend services. In the case of AWS, Amazon API Gateway provides a comprehensive solution to create, publish, maintain, monitor, and secure APIs at any scale.
Key Features of API Gateway:
- Support for stateful WebSocket and stateless HTTP and REST APIs.
- Provides various authentication methods such as AWS IAM, Lambda authorizer, and Amazon Cognito user pools.
- Built-in support for CORS (Cross-Origin Resource Sharing) and automatic deployments.
- Offers a developer portal for publishing RESTful APIs.
- Enables logging and monitoring of API usage and changes.
- Supports Infrastructure as Code (IaC) tools like AWS CloudFormation templates for seamless API creation.
Building an End-to-End HTTP API:
In this guide, we’ll focus on creating an end-to-end HTTP API that allows users to retrieve information from a database and add new data to it. Let’s get started:
Step 1: Create a Lambda Function
Begin by going to the Lambda console and creating a new Lambda function that will handle the API requests.
Step 2: Create an HTTP API
Next, navigate to the API Gateway console and choose the option to build an HTTP API.
Configure the integrations and provide a name for the API.
Configure routes for the HTTP API to define the endpoints. You can add multiple routes as needed.
Specify a stage name for the API and consider enabling the auto-deploy option to streamline the deployment process.
Review the configuration and create the API.
You will receive details about the created API.
Step 3: Write Lambda Function Code for GET Method
To handle GET requests, update the Lambda function code accordingly. You can test the API using tools such as Postman by copying the invoke URL from the API Gateway and making a request.
Update lambda function code.
Now you can check in Postman the results.
Step 4: Create a Lambda Function for POST Data
Similarly, create a new Lambda function to handle POST requests by following the same process as in Step 1.
Step 5: Create a New Route in the HTTP API
Go to the Routes section in the API Gateway console and create a new route.
Attach the integration to the Lambda function created in the previous step and grant the necessary permissions to invoke the Lambda function.
Step 6: Write Lambda Code for POST Method
Write the Lambda function code to handle the POST requests. Use Postman or similar tools to test the API and verify the results.
Congratulations! You have successfully built an HTTP API using Amazon API Gateway and Lambda functions to handle GET and POST requests. This comprehensive solution allows users to interact with the API and perform various operations on the database.