EC2 Scheduler Terraform Module

This Terraform module automates the scheduling of AWS EC2 instances by starting and stopping them based on user-defined tags. It utilizes Amazon EventBridge to trigger actions hourly, optimizing resource usage and reducing costs.

Features

• ⏰ Automatically starts/stops EC2 instances based on start_at and stop_at tags.
• 🌍 Supports multiple AWS regions via region_list.
• 🕒 Optional support for time zone adjustment using the time_zone variable (based on pytz time zones).
• 🔁 EventBridge rule triggers every hour to evaluate and apply schedule logic.
• 🔒 Built-in validation for allowed time zones.

How It Works

1. Tag EC2 instances with:

   • start_at: Hour (00–23) when the instance should start
   • stop_at: Hour (00–23) when the instance should stop

2. Deploy the module in your Terraform configuration to enable the automation.

3. Every hour, EventBridge invokes a Lambda function that:

   • Checks the current hour in the configured time zone.
   • Starts/stops instances as needed based on their tags.

Usage

module "start-stop-ec2" {
  source      = "../../../../public-cloud-iac-terraform-modules/aws/modules/ec2_scheduler"
  region_list = ["eu-north-1", "eu-west-1"]
  time_zone   = "Europe/Stockholm"
}

Input Variables

Name	Description	Type	Default	Required
region_list	List of AWS regions to target for scheduling.	list(string)	["eu-north-1", "eu-west-1", "eu-central-1", "us-west-1"]	No
time_zone	Time zone used for evaluating start_at/stop_at tags. Should match pytz names.	string	"Europe/Stockholm"	No

Example EC2 Tagging

To schedule an EC2 instance to start at 8:00 AM and stop at 6:00 PM:

aws ec2 create-tags \
  --resources i-0123456789abcdef0 \
  --tags Key=start_at,Value=8:00 Key=stop_at,Value=18:00

Outputs

No outputs are currently defined by this module.

Requirements

• Terraform >= 1.0
• AWS provider