Creating an AWS Lambda Function Using Serverless Framework

#cloud #aws #lambda #azure

🔥 What is AWS Lambda?

AWS Lambda is a serverless compute service that lets you run code without managing servers. You simply upload your code, and Lambda automatically handles the infrastructure, scaling, and execution.

🛠️ Benefits of Using Serverless Framework

The Serverless Framework is a powerful open-source tool that simplifies the process of creating and managing AWS Lambda functions.

✅ Key Advantages

Simplifies Deployment: Easily deploy Lambda functions with simple commands.
Infrastructure as Code: Use the serverless.yml file to define infrastructure and configuration.
Supports Multiple Providers: AWS, Azure, Google Cloud, etc.
Built-in Support: Manages API Gateway, DynamoDB, S3, and other AWS services.

🔥 1. Install Serverless Framework

First, install the Serverless CLI globally using npm:

npm install -g serverless

Verify the installation:

serverless --version

🛠️ 2. Create a New Serverless Project

Generate a new Serverless project with AWS as the provider:

serverless create --template aws-nodejs --path my-lambda-function

aws-nodejs → AWS Lambda with Node.js runtime.
my-lambda-function → Your project folder name.

Go into the project directory:

cd my-lambda-function

🔧 3. Install Dependencies

Install the necessary dependencies:

npm install

🌐 4. Configure AWS Credentials

If you haven’t already, configure your AWS credentials:

serverless config credentials --provider aws --key <AWS_ACCESS_KEY> --secret <AWS_SECRET_KEY>

✅ Get your access key and secret key from AWS IAM.

🛠️ 5. Edit `serverless.yml` Configuration

Open the serverless.yml file and define your Lambda function:

service: my-lambda-service

provider:
  name: aws
  runtime: nodejs18.x
  region: us-east-1

functions:
  hello:
    handler: handler.hello
    events:
      - http:
          path: hello
          method: get

✅ Explanation:

service: Name of your Lambda service.
provider: AWS settings, including the region and runtime.
functions: The Lambda function definition.
events: Triggering the Lambda through an HTTP request.

🔥 6. Write the Lambda Function

Open the handler.js file and add the following code:

module.exports.hello = async (event) => {
  return {
    statusCode: 200,
    body: JSON.stringify({
      message: "Hello from Lambda!",
      input: event,
    }),
  };
};

✅ This function returns a simple JSON response.

🚀 7. Deploy the Lambda Function

Deploy your Lambda function to AWS:

serverless deploy

Once deployed, you’ll see the API Gateway endpoint:

Service deployed to: https://<your-api-id>.execute-api.<region>.amazonaws.com/dev/hello

🌐 8. Test the Lambda Function

You can test the function using:

curl https://<your-api-id>.execute-api.<region>.amazonaws.com/dev/hello

Or:

serverless invoke -f hello

⚙️ 9. Cleaning Up

To remove the Lambda function and free up resources:

serverless remove

✅ Key Takeaways

Serverless Framework simplifies AWS Lambda deployment.
Automatic Scaling: No need to manage infrastructure.
Cost-Efficient: You only pay for what you use.
Quick Deployment: Easily create and deploy Lambda functions with minimal configuration.