CloudWatch alarm actions should be enabled

How to fix it

Enable actions on the metric alarm the finding names, which is the ActionsEnabled flag. That flag is the whole of what this check reads, so an alarm with no action configured passes as soon as it is on and still does nothing when it fires; whether it carries an action for the ALARM state is CloudWatch.15. Enabling is not a quiet change either, because an alarm already in ALARM runs its actions at its next evaluation, so read what those actions are first.

In the console

CloudWatch → Alarms → All alarms → the alarm → Actions

With the AWS CLI

aws cloudwatch enable-alarm-actions --alarm-names <alarm-name> --region <region>

With Terraform

resource "aws_cloudwatch_metric_alarm" "this" {
  alarm_name          = var.alarm_name
  comparison_operator = var.comparison_operator
  evaluation_periods  = var.evaluation_periods
  metric_name         = var.metric_name
  actions_enabled     = true
}