Lambda Functions Setup

Lambda Functions Overview

The Weather Platform uses several Lambda functions to manage IoT devices and provide APIs for data access.

Function Overview

IoT Device Management:

• addThing: Register new weather devices
• deleteThing: Remove weather devices
• fetchThings: List all registered devices
• getIoTEndpoint: Get IoT Core endpoint URL

Data Access:

• getDataset: Retrieve processed weather datasets
• getTotalReadings: Get telemetry statistics

Key Functions Detailed

addThing Function

Purpose: Register new IoT weather devices Trigger: API Gateway (POST) Functionality:

• Creates IoT Thing in AWS IoT Core
• Adds device to ITeaWeatherHub Thing Group
• Attaches WeatherStationPolicies
• Returns device credentials

getTotalReadings Function

Purpose: Get statistics from the data lake Integration: Connects to itea-weather-data-lake-storage Functionality:

• Scans S3 bucket for telemetry files
• Counts total readings per location
• Returns aggregated statistics

getDataset Function

Purpose: Retrieve processed weather datasets Integration: Connects to processed data bucket Functionality:

• Lists available datasets
• Provides download URLs
• Handles CloudFront integration

Deployment and Configuration

Lambda functions are automatically deployed with the Amplify backend:

# Functions deploy with sandbox
npx ampx sandbox --profile ws1-amplify

Environment Variables

Functions automatically receive:

• IoT Core endpoint URL
• S3 bucket names
• Cognito User Pool information
• AWS region configuration