Configure Lambda Function getStudentData

Objective: Create and configure the Lambda function getStudentData to retrieve all student data from the DynamoDB studentData table, including fields Student ID (studentid), Full Name (name), Class (class), Date of Birth (birthdate), and Email (email). This function uses the Scan operation to fetch the data and returns the results in JSON format, supporting integration with the web interface via API Gateway.

The function will use Python 3.13, architecture x86_64, assigned the IAM role LambdaGetStudentRole (created in section 2.1), and integrated with DynamoDB.

Initial Requirements

You need to complete the preparation steps in section 2 (IAM Role LambdaGetStudentRole, DynamoDB table studentData) before creating the function. Ensure your AWS account is ready and the AWS region is us-east-1.

Overview of the getStudentData Function

The getStudentData function performs the following tasks:

  • Connects to the DynamoDB studentData table in the AWS region (default is us-east-1).
  • Performs a Scan operation to retrieve all student data, handling pagination if the table is large.
  • Returns the data in JSON format with a CORS header (Access-Control-Allow-Origin: '*') so that the web interface (running on CloudFront) can access it via API Gateway.
  • Logs to CloudWatch for monitoring and debugging (supported by the AWSLambdaBasicExecutionRole policy).

Detailed Steps

  1. Access AWS Management Console

    • Open your browser and log in to the AWS Management Console with your AWS account.

    • In the search bar at the top, type Lambda and select AWS Lambda to enter the management interface.

    • Ensure the AWS region is us-east-1 (matching the studentData table), check in the top-right corner of the AWS Console.

      AWS Console with Lambda Search Bar Figure 1: AWS Console interface with the Lambda search bar.

  2. Navigate to Functions Section

    • In the AWS Lambda interface, look at the left-hand navigation menu.

    • Select Functions to see the list of existing Lambda functions. If none exist, the list will be empty.

      Navigation Menu with Functions Option Figure 2: Navigation menu with the Functions option.

  3. Start the Create Function Process

    • In the Functions interface, click the Create function button in the top-right corner to start configuring a new function.

      Create Function Button in Functions Interface Figure 3: Create function button in the Functions interface.

  4. Configure Basic Function Information

    • In the Function type section, select Author from scratch.

    • In the Function name field, enter getStudentData.

    • In the Runtime section, select Python 3.13. If Python 3.13 is unavailable, select the latest version (e.g., Python 3.12 or 3.11).

    • In the Architecture section, select x86_64.

      Basic Function Information Configuration Figure 4: Basic function configuration interface.

    • In the Permissions section, choose Use an existing role, and select LambdaGetStudentRole (created in section 2.1, including AWSLambdaBasicExecutionRole, AmazonDynamoDBReadOnlyAccess, AmazonS3FullAccess, CloudFrontFullAccess).

    • Note: AmazonS3FullAccess and CloudFrontFullAccess are not used in the current code but are retained from previous requirements.

    • Keep the other settings as defaults and click Create function.

      Select LambdaGetStudentRole and Create Function Figure 5: Select LambdaGetStudentRole and click Create function.

  5. Check the Function Creation Status

    • After clicking Create function, you will be redirected to the getStudentData function details page.

    • The interface will display a message like: “Successfully created the function getStudentData. You can now change its code and configuration. To invoke your function with a test event, choose Test.”

    • If you don’t see this message or encounter an error, check that LambdaGetStudentRole exists and that your AWS account has the lambda:CreateFunction permission.

      Function Details Page After Creation Figure 6: Function details page after creating getStudentData.

  6. Configure Source Code

    • In the Code tab, scroll down to the Code source section.
    • In the lambda_function.py file, delete the default code and paste the following:
import json
import boto3

def lambda_handler(event, context):
    # Connect to DynamoDB in the us-east-1 region
    dynamodb = boto3.resource('dynamodb', region_name='us-east-1')
    table = dynamodb.Table('studentData')

    # Retrieve all data from the studentData table
    response = table.scan()
    data = response['Items']

    # Continue scanning if there is more data (pagination)
    while 'LastEvaluatedKey' in response:
        response = table.scan(ExclusiveStartKey=response['LastEvaluatedKey'])
        data.extend(response['Items'])

    # Return the data in JSON format
    return {
        'statusCode': 200,
        'body': json.dumps(data),
        'headers': {
            'Content-Type': 'application/json',
            'Access-Control-Allow-Origin': '*'
        }
    }