AWS EC2 Auto-Recovery with Terraform & Lambda

Serverless Monitoring with AWS Lambda: Event-driven Architecture

Table of Contents

• Overview
• Features
• Tech Stack
• Project Structure tree
• Running the code
• Test
• Contact / Feedback

Overview

This project provisions an AWS-based infrastructure using Terraform. It includes an EC2 instance that is automatically restarted via an AWS Lambda function triggered by a CloudWatch Event. The Lambda function also notifies a user via SNS email notification. The project demonstrates infrastructure automation, serverless programming, and event-driven architecture.

Features

Automatic EC2 instance recovery
Lambda function triggers on EC2 stop events
Email alerts via SNS
Fully IaC-driven setup using Terraform
Environment variable integration

Tech Stack

Terraform (remote state with S3 + S3 locking)
AWS Lambda (Python 3.x)
AWS EC2
CloudWatch Events (EventBridge)
SNS
IAM

Project Structure

Running the code

Clone the repository

git clone https://github.com/m-alkhalil/awsMonitor_lambda.git

create py venv and install python packages

python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

Configure AWS so terraform can use the configured profile:

run:

aws configure

provide:

• AWS Access Key ID
• AWS Secret Access Key
• Default region name
• Default output format

Provision s3 backend:

cd infra-backend/
terraform init
terraform plan
terraform apply

Provision Infrastructure :

add the receiver email in main.tf: sns_receiver_email = "[email protected]"

cd ../infra
terraform init
terraform plan
terraform apply

Test

Success case (when everything works as expected).

Failure cases:

• Missing environment variables.
• Missing instance ID in the event.
• EC2 start failures.
• SNS publish failures.
• Edge cases (empty or malformed events).

Test was written according to the following flow:

• Write a test function using pytest
• Mock AWS services using unittest.mock
• Simulate inputs (the EventBridge payload)
• Call lambda_handler
• Assert behavior (return values, AWS calls)

testing locally:

add the following line after the lambda_handler function definition in main_lambda.py:

if __name__ == "__main__":
     test_event = {
         "detail": {
             "instance-id": "i-00544787ec36918d5",
             "state": "stopped"
         }
     }
     lambda_handler (test_event, None)

unit test and pytest

• Arrange: prepare mocks and inputs, simply find out and prepare everything my function(lambda_handler) needs to work.
• Act: make the function call.
• Assert: check if EC2 start instance was called and SNS message was sent.

running tests

pytest

Contact / Feedback

Feel free to open issues or reach out via LinkedIn:

Mahran Alkhalil