Building An API Using AWS Lambda and API Gateway

Table of Contents

In this article, we will learn about building an API using AWS lambda and API gateway. AWS Lambda is an Amazon Web Service compute service that lets you run code without managing or provisioning servers. Lambda runs your code on a high-availability compute infrastructure with all computing resources managed, including server and operating system maintenance, capacity provisioning, automatic scaling, and logging.

API Gateway is an AWS service that provides the ability to create, publish, secure, maintain, monitor, and maintain APIs at any scale. As an API developer, you can make APIs available to third-party or use them in your own client applications. API gateways act as reverse proxy servers, accepting API requests, aggregating the various services required to fulfill them, and returning appropriate responses.

Prerequisites

AWS account
Basic AWS Lambda and API Gateway concept

Building an API using AWS Lambda and API Gateway

Create a Lambda Function

Go to AWS Console and Log In
In the search bar, type lambda
Select the Lambda options displayed under Services section

Then AWS Lambda page will appear and click the Create function button on the right side of the page.
Then let’s create a function named apiWithLambda . Then click Create Function.

After some time a lambda function will be created and you will be redirected to the following page.

Now, let’s test the lambda function by clicking the Test under Code Source and then, setting up a test event.

Now, click on create new event and specify an Event name as testEvent, any name you like, before clicking save.

After that, click Test to verify whether the Lambda function was executed or not. We can view the execution logs in the output. The text Hello from Lambda! should appear in the log output along with a 200 response code.

Build API Gateway

In the search bar, type api gateway
Select the API Gateway options displayed under Services section

Now, go to the dashboard of API Gateway and click Create API button.
Then, Under the REST API section click Build.

After completing above steps, now click on the New API option under the Create new API section and also enter the desired API name.

Now, On the page for configuration. Go to Resource> Actions > create Method. Create a GET method and select the Lambda Function option as the integration type. Then select the name of the Lambda function previously created and click Save.