Deploying a Node.js Serverless Application to AWS with AWS CDK
Tags: node, aws, cdk, severless
Published: 2023-04-14 11:25:53

The popularity of serverless architecture is growing as a result of its affordability and scalability. In this blog article, we’ll look at utilising the AWS CDK to deploy a Node.js serverless application to AWS.

Prerequisites

Make sure you have the following installed before we begin:

- Node js
- AWS CLI
- AWS CDK CLI

---

## Setting Up the Project
To start, create a new directory for your project and navigate to it in your terminal. Then, run the following command to initialize a new Node.js project:

```
$ npm init -y
```

This will create a new package.json file with default values. Next, let’s install the AWS SDK for Node.js and the AWS CDK:

```
$ npm install aws-sdk aws-cdk-lib aws-cdk-lib@1.104.0
```

The most recent versions of the AWS CDK and the AWS SDK for Node.js will be installed as a result. AWS CDK version 1.104.0 is also what we specify in order to prevent compatibility problems.

## Your Serverless Application Writing

Write a straightforward Node.js serverless application that prints a message to the console. In your project directory, make a new file called index.js, and then add the following code:

```
exports.handler = async (event) => {
  console.log("Hello, world!");
  return {
    statusCode: 200,
    body: JSON.stringify({
      message: "Hello, world!"
    })
  };
};
```


The “Hello, world!” message is logged to the console by this function, and it also sends the same message as an HTTP response. This procedure will be used as our AWS Lambda function.

## The AWS CDK Stack: Definition

The AWS CDK stack that will be used to deploy our serverless application there must then be defined. In your project directory, make a new file called app.js, and then add the following code:

```
const cdk = require('aws-cdk-lib');
const lambda = require('aws-cdk-lib/aws-lambda');
const apigateway = require('aws-cdk-lib/aws-apigateway');

class MyStack extends cdk.Stack {
  constructor(scope, id, props) {
    super(scope, id, props);

    // Create a new Lambda function
    const myFunction = new lambda.Function(this, 'MyFunction', {
      runtime: lambda.Runtime.NODEJS_14_X,
      handler: 'index.handler',
      code: lambda.Code.fromAsset('index.js')
    });

    // Create a new API Gateway
    const api = new apigateway.RestApi(this, 'MyApi');

    // Add a new resource and method to the API Gateway
    const hello = api.root.addResource('hello');
    const integration = new apigateway.LambdaIntegration(myFunction);
    hello.addMethod('GET', integration);
  }
}

const app = new cdk.App();
new MyStack(app, 'MyStack');
```

This code creates a new Lambda function and API Gateway AWS CDK stack. The earlier-created index.js file is used by the Lambda function, which is triggered by an HTTP endpoint made available by the API Gateway.

## Implementing AWS

We must build a fresh AWS CDK stack and deploy it using the AWS CDK CLI in order to deploy our serverless application to AWS. Enter the commands below into your terminal:

```
$ cdk init app --language javascript
$ cdk synth
$ cdk deploy

```
In your project directory, the first command launches a new AWS CDK app. For our AWS CDK stack, the second command creates a CloudFormation template. Our AWS CDK stack is deployed to AWS using the third command.

---

To sum up, using the AWS CDK to deploy a Node.js serverless application to AWS is a simple process that delivers excellent scalability and cost-effectiveness.

I appreciate you taking the time to read this blog article, and I genuinely hope that the advice and tips will be helpful to you. I would love to hear from you in the comments box below if you have any queries, comments, or recommendations.