cdk-ec2-autostop

This project demonstrates how to use the CDK to create an EC2 instance that automatically stops when there are no more active SSH or Session Manager connections to it. This can be useful for an instance that is only used occasionally to remotely access an RDS cluster.

When you deploy this stack and EC2 instance is provisioned that automatically stops after running for about 15-30 minutes without an SSH or Session Manager connection. It can be manually re-started at any time and will again be automatically stopped after running for about 15-30 minutes without an SSH or Session Manager connection.

This project implements the following solution:

1. Install a bash script report-metrics.sh that publishes a CloudWatch metric named Active that indicates whether the current instance is "active" or not. We consider an instance to be active if it has any incoming SSH or Session Manager connections or if it was recently booted.

2. Configure a cronjob to run report-metrics.sh on the instance once a minute.

3. Configure a CloudWatch Alarm that stops the instance once it remains inactive over a 15 minute period.

NOTES:

• As currently implemented you can only use Session Manager to connect to this instance.
• If you want to connect directly with SSH you must do the following:
  • Create an EC2 Key Pair
  • Edit cdk-ec2-autostop-stack.ts to set keyName to the name of your key
  • Edit cdk-ec2-autostop-stack.ts to uncomment the line that allows SSH connections

Useful commands

• npm run build compile typescript to js
• npm run watch watch for changes and compile
• npm run test perform the jest unit tests
• cdk deploy deploy this stack to your default AWS account/region
• cdk diff compare deployed stack with current state
• cdk synth emits the synthesized CloudFormation template