[Hands- On] AWS Lambda: Build & Deploy Your First Function

Before starting, ensure to have:
✅ An AWS Free Tier account
✅ AWS CLI installed and configured (aws configure)
✅ IAM user with Lambda permissions
✅ Node.js or Python installed (for function development)

AWS Lambda needs execution permissions.

1️⃣ Go to IAM → Roles → Create Role
2️⃣ Select AWS service → Lambda → Click "Next"

3️⃣ Attach the following permissions:

AWSLambdaBasicExecutionRole

AWSLambdaVPCAccessExecutionRole (if using VPC)

4️⃣ Name the role (e.g., LambdaExecutionRole) and create it.

1️⃣ Open AWS Lambda in the AWS Management Console
2️⃣ Click Create Function
3️⃣ Select Author from Scratch
4️⃣ Function Name: hello-world-lambda
5️⃣ Runtime: Choose Python 3.13
6️⃣ Execution Role: Select the IAM Role created earlier
7️⃣ Click Create Function

Replace the default code with:

import json

def lambda_handler(event, context):

return {

"statusCode": 200,

"body": json.dumps("Hello from AWS Lambda!")

}

Click Deploy

1️⃣ Click on Test

2️⃣ Configure a new test event with { "key": "value" }
3️⃣ Click Test again
✅ You should see "Hello from AWS Lambda!" in the response

To avoid unnecessary AWS charges: delete lambda function

CLI command:

aws lambda delete-function --function-name hello-world-lambda

𝘾𝒐𝙣𝒈𝙧𝒂𝙩𝒖𝙡𝒂𝙩𝒊𝙤𝒏𝙨! 𝒀𝙤𝒖 𝒋𝙪𝒔𝙩 𝙗𝒖𝙞𝒍𝙩 & 𝙙𝒆𝙥𝒍𝙤𝒚𝙚𝒅 𝒚𝙤𝒖𝙧 𝙛𝒊𝙧𝒔𝙩 𝘼𝑾𝙎 𝙇𝒂𝙢𝒃𝙙𝒂 𝒇𝙪𝒏𝙘𝒕𝙞𝒐𝙣!

Other things, we can do with AWS Lambda

Run the following command:

aws lambda invoke --function-name hello-world-lambda output.json

Check output.json to see the response.

To invoke Lambda via HTTP:
1️⃣ Go to AWS API Gateway
2️⃣ Create a REST API
3️⃣ Create a new resource & method (GET)
4️⃣ Integrate it with Lambda Function
5️⃣ Deploy the API → Get the Invoke URL
6️⃣ Test via browser or Postman