Adding cloudwatch alarm through the CLI
aws cloudwatch put-metric-alarm --alarm-name "CPUUtilization $DB" --alarm-description "$METRIC" --actions-enabled
--alarm-actions "$TOPIC_ARN" --metric-name "CPUUtilization" --namespace "AWS/RDS" --statistic "Maximum"
--dimensions "Name=DBInstanceIdentifier,Value=$DB" --period 300 --evaluation-periods 2 --threshold 1848000
--comparison-operator GreaterThanOrEqualToThreshold --treat-missing-data notBreaching --region $REGION