Terraform module for EC2 cloudwatch alarms

This module will create AWS Cloudwatch metric alarms for instance and system, SNS topic and SNS topic subscription.

Instance reboot alarm has higher default evaluation_periods and datapoints_to_alarm to allow remediation using recover on system check failure when both alarms firing. Once a cloudwatch alarm gets into alarm state, the configured action is performed and message sent to SNS topic.

Alarms have alarm_actions configured as follows:

Instance check	System check	Action
✅	✅	none
❌	✅	reboot
✅	❌	recover
❌	❌	recover

See Requirements for enabling CloudWatch action based recovery

Usage

module "ec2_alarm" {
  source  = "cookielab/ec2-cloudwatch-alarms/aws"
  version = "~> 0.0"

  ec2_instance_id = "i-08bdd64b00da931ed"

  sns_topic_subscription_email_address = "monitoring@example.com"
}

Requirements

Name	Version
terraform	>= 1.9, < 2.0
aws	~> 6.0

Providers

Name	Version
aws	~> 6.0

Modules

No modules.

Resources

Name	Type
aws_cloudwatch_metric_alarm.instance_check	resource
aws_cloudwatch_metric_alarm.system_check	resource
aws_sns_topic.this	resource
aws_sns_topic_subscription.this	resource
aws_instance.this	data source
aws_region.current	data source
aws_sns_topic.this	data source

Inputs

Name	Description	Type	Default	Required
cloudwatch_alarm_options	Cloudwatch Alarms options	object({ instance = optional(object({ actions_enabled = optional(bool, true) comparison_operator = optional(string, "GreaterThanOrEqualToThreshold") evaluation_periods = optional(number, 2) datapoints_to_alarm = optional(number, 2) period = optional(number, 60) statistic = optional(string, "Maximum") threshold = optional(number, 1) treat_missing_data = optional(string, "notBreaching") }), {}) system = optional(object({ actions_enabled = optional(bool, true) comparison_operator = optional(string, "GreaterThanOrEqualToThreshold") evaluation_periods = optional(number, 6) datapoints_to_alarm = optional(number, 6) period = optional(number, 60) statistic = optional(string, "Maximum") threshold = optional(number, 1) treat_missing_data = optional(string, "notBreaching") }), {}) })	{}	no
create_sns_topic	Toggle creation of SNS topic for Cloudwatch alarms	bool	true	no
create_sns_topic_subscription	Toggle creation of SNS Topic subscription	bool	true	no
ec2_instance_id	EC2 Instance ID to create Cloudwatch alarms for	string	n/a	yes
sns_topic_name	SNS Topic name to use for alarms	string	"ec2-cloudwatch-alarm"	no
sns_topic_subscription_email_address	E-mail address for SNS Topic subscribtion	string	null	no
tags	Map of tags to be set on resources	map(string)	{}	no

Outputs

Name	Description
sns_topic_name	Name of the created SNS Topic