CloudWatch Alarm - CPU Utilization

📦 Overview

This Terraform module provisions a CloudWatch alarm to monitor CPU utilization for a specified EC2 instance.

It’s ideal for proactive monitoring of performance bottlenecks and workload surges in development, staging, or production environments.

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✅ Key Features

• Monitors CPU usage and triggers alerts above a defined threshold
• Customizable evaluation period, threshold, and comparison operator
• Compatible with SNS for optional notifications
• Tagged by environment for visibility and filtering

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💼 Use Cases

• Alerting for high CPU usage on critical EC2 workloads
• Triggering auto-scaling based on compute pressure
• Monitoring under-provisioned instances in dev/test/staging
• Integrating alarms into broader observability pipelines

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📥 Input Variables

Name	Type	Description
region	string	AWS region where the EC2 instance is running
instance_id	string	The ID of the EC2 instance to monitor
threshold_percent	number	CPU usage threshold that triggers the alarm (e.g., 80 for 80%)
evaluation_periods	number	Number of consecutive periods the threshold must be breached
alarm_name	string	The name to assign to the CloudWatch alarm
environment	string	Tag to specify the deployment environment (e.g., dev, staging, prod)

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📤 Outputs

Name	Description
alarm_name	The name of the CloudWatch alarm
alarm_arn	The ARN of the provisioned CloudWatch alarm

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🚀 Deployment Readiness

• ✅ Compatible with Terraform 1.0+
• ✅ Tested with AWS provider 5.x
• 🧪 Requires an existing EC2 instance in the target region

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🛠️ Example Usage

module "cloudwatch-alarm-cpu-deployment" {
  source             = "git::ssh://git@github.com/archiphire/aws-level-1-modules.git//monitoring/cloudwatch-alarm-cpu?ref=v1.0.0"

  region             = "us-east-1"
  instance_id        = "i-0123456789abcdef0"
  threshold_percent  = 80
  evaluation_periods = 2
  alarm_name         = "high-cpu-alert"
  environment        = "prod"
}

terraform init
terraform plan
terraform apply

or

tofu init
tofu plan
tofu apply

🧹 Cleanup Options

terraform destroy

or

tofu destroy

Manual Deletion (production):

aws cloudwatch delete-alarms --alarm-names high-cpu-alert

🛡️ Notes

This is a Level 1 monitoring module. For production use, consider pairing with:

sns-topic-basic for alert notifications

Auto Scaling policies triggered by alarm actions

🔒 Deployment Package Notice

This module is part of the Level 1 AWS License Tier. To access the full deployment package and source code, subscribe to Archiphire.