EC2 Instance Scheduler with Slack Notifications

Overview

This CloudFormation template creates an automated EC2 instance scheduler using AWS Lambda and EventBridge. It helps reduce AWS costs by automatically starting and stopping non-production instances based on defined working hours. Additionally, it includes a resource-checking Lambda function that identifies untagged resources and sends notifications via Slack.

Features

• Automated Scheduling: Uses EventBridge to trigger Lambda functions for starting and stopping instances.
• Tag-Based Control: Only instances tagged with AutoStop: true are affected.
• Slack Notifications: Notifies a Slack channel whenever instances are started or stopped.
• Daily Resource Audit: Checks for untagged EC2 instances, EBS volumes, and Elastic IPs, sending a report to Slack.
• Secrets Manager Security: Stores Slack Webhook URL securely.
• Production-Safe: Ensures production workloads remain unaffected.

Cost Savings Example

• Monthly EC2 costs reduced from $8,500 to $3,145.
• Identified $950 worth of untagged resources in the first week.

Deployment

Prerequisites

• AWS account with appropriate IAM permissions for CloudFormation, Lambda, and EC2.
• Slack Webhook URL for notifications.
• Slack Webhook URL stored in AWS Secrets Manager.

Steps

1. Deploy the CloudFormation template.
2. Provide working hours (UTC format) for instance start/stop times.
3. Add the AutoStop: true tag to all non-production instances.
4. Monitor Slack notifications for instance actions and untagged resources giving cost savings insights.
5. Configure working hours using the WorkingHoursStart and WorkingHoursEnd parameters.

CloudFormation Template

This repository contains a CloudFormation YAML file that defines:

• An IAM role with permissions for EC2 and Lambda.
• Two Lambda functions:
  • InstanceSchedulerFunction for managing EC2 instances.
  • UntaggedResourcesFunction for identifying untagged resources.
• EventBridge rules to trigger Lambda functions on schedule.
• Slack integration for automated notifications.

Customization

Modify the WorkingHoursStart and WorkingHoursEnd parameters in the CloudFormation template to adjust instance schedules.

How It Works

1. Instance Scheduling:
   • Starts instances at WorkingHoursStart.
   • Stops instances at WorkingHoursEnd.
   • Sends a Slack notification after each action.
2. Daily Resource Audit:
   • Scans EC2, EBS volumes, and Elastic IPs for missing tags.
   • Sends a Slack report listing untagged resources.

Next Steps

• Deploy the CloudFormation stack.
• Tag your instances appropriately.
• Monitor Slack for instance activity and untagged resources.

Troubleshooting

• Lambda Fails? Check CloudWatch logs for errors.
• Slack Notifications Not Sending? Verify the webhook URL in AWS Secrets Manager.
• EC2 Not Starting/Stopping? Ensure instances are tagged with AutoStop: true.

Contributing

Feel free to submit pull requests for improvements!

License(s)

MIT