Add two CloudWatch alarm

add_cloudwatch_alarms.rb

require 'aws-sdk'

REGION = 'ap-northeast-1'
WAIT_INTERVAL = 1

def put_alarms(instance_id)
  cloudwatch = Aws::CloudWatch::Client.new(region: REGION)

  cloudwatch.put_metric_alarm(
    alarm_name: "cpu-mon-#{instance_id}",
    alarm_description: "Alarm when CPU exceeds 70 percent",
    actions_enabled: true,
    alarm_actions: ['<ARN send notification to>'],
    metric_name: 'CPUUtilization',
    namespace: 'AWS/EC2',
    statistic: 'Average',
    dimensions: [
      {
        name: 'InstanceId',
        value: instance_id
      }
    ],
    period: 300,
    evaluation_periods: 1,
    threshold: 70,
    comparison_operator: 'GreaterThanOrEqualToThreshold'
    )

  cloudwatch.put_metric_alarm(
    alarm_name: "status-checked-failed-#{instance_id}",
    alarm_description: "Alarm when any status check failed",
    actions_enabled: true,
    alarm_actions: ['<ARN send notification to>'],
    metric_name: 'StatusCheckFailed',
    namespace: 'AWS/EC2',
    statistic: 'Maximum',
    dimensions: [
      {
        name: 'InstanceId',
        value: instance_id
      }
    ],
    period: 60,
    evaluation_periods: 2,
    threshold: 1.0,
    comparison_operator: 'GreaterThanOrEqualToThreshold'
  )
  sleep(WAIT_INTERVAL)
end

Aws::EC2::Resource.new(region: REGION) \
  .instances.each { |instance|  put_alarms(instance.id) }