How to snooze all cloudwatch alarms at a specific time using Terraform?

In AWS CloudWatch, you can use Terraform to set up a snooze option for your alarms. Snoozing alarms allows you to temporarily suppress notifications and actions triggered by the alarms during maintenance periods or scheduled downtime. In this article, we’ll explore how to implement a snooze option for alarms in AWS CloudWatch using Terraform.

Prerequisites:

• An AWS account with appropriate permissions to create CloudWatch Event rules and targets.
• Terraform installed on your local machine.

Step 1: Terraform Setup:

Before we dive into the code, ensure that you have set up Terraform on your machine and have a working directory ready for the Terraform configuration files.

Step 2: Define the CloudWatch Event Rule:

In your Terraform configuration file, define a CloudWatch Event Rule that will trigger the snooze action for your alarms. The rule will specify the schedule for snoozing the alarms. For example, snoozing every Sunday from 12:30 PM to 6:30 PM CST.

resource "aws_cloudwatch_event_rule" "snooze_alarms_rule" {
  name        = "snooze_alarms_rule"
  description = "Snooze alarms every Sunday from 12:30 PM to 6:30 PM CST"
  schedule_expression = "cron(30 18 ? * SUN *)" # 6:30 PM CST is 12:30 AM UTC, so we use that timezone
}

Step 3: Define the Event Target:

Next, define the CloudWatch Event Target, which specifies the action to be performed when the event rule is triggered. In this case, we want to snooze the alarms. Instead of using the “arn:aws:automate” target (which is not supported), we’ll use an SNS topic as the target. You can create an SNS topic in your AWS account and provide its ARN as the target.

resource "aws_cloudwatch_event_target" "snooze_alarms_target" {
  rule      = aws_cloudwatch_event_rule.snooze_alarms_rule.name
  arn       = "<sns_topic_arn>"  # Replace with the ARN of your SNS topic
  target_id = "snooze_alarms_target"
  input = jsonencode({
    "Action":       "Snooze",
    "StateValue":   "ALARM",
    "Description":  "Snoozing all alarms for maintenance",
    "Duration":     21600 # 6 hours in seconds
  })
}

Make sure to replace <sns_topic_arn> with the actual ARN of your SNS topic.

Within the CloudWatch Event Target, configure the snooze parameters. These parameters include the action, state value, description, and duration. You can customize these values according to your specific snooze requirements. For example, setting the state value to “ALARM” and the duration to 6 hours (21600 seconds).

Then apply the Terraform Configuration: Once you have defined the CloudWatch Event Rule and Target, save the Terraform configuration file and execute the “terraform apply” command in your working directory. Terraform will provision the necessary resources and configure the snooze option for your alarms.

Conclusion:

In this article, we’ve seen how to implement a snooze option for alarms in AWS CloudWatch using Terraform. By defining a CloudWatch Event Rule and specifying an SNS topic as the target, we can easily snooze alarms during maintenance periods or scheduled downtime. This approach allows you to temporarily suppress notifications and actions triggered by the alarms, ensuring uninterrupted maintenance activities.