AWS CloudWatch alarm rename script

aws_cloudwatch_alarm_rename.py

# 2020-11-30
#
# code from gist fork:
#
# update alarm names from 3 cli args:
# - old alarm name
# - new alarm name 
# - new alarm threshold
#

import sys
import boto3


def rename_alarm(alarm_name, new_alarm_name, new_alarm_threshold = ''):
    client = boto3.client('cloudwatch')
    alarm = client.describe_alarms(AlarmNames=[alarm_name])
    if not alarm:
        raise Exception("Alarm '%s' not found" % alarm_name)
    alarm = alarm['MetricAlarms'][0]
    if new_alarm_threshold = '':
        new_alarm_threshold = alarm['Threshold']
    client.put_metric_alarm(
        AlarmName=new_alarm_name,
        ActionsEnabled=alarm['ActionsEnabled'],
        OKActions=alarm['OKActions'],
        AlarmActions=alarm['AlarmActions'],
        InsufficientDataActions=alarm['InsufficientDataActions'],
        MetricName=alarm['MetricName'],
        Namespace=alarm['Namespace'],
        Statistic=alarm['Statistic'],
        Dimensions=alarm['Dimensions'],
        Period=alarm['Period'],
        EvaluationPeriods=alarm['EvaluationPeriods'],
        Threshold=alarm['Threshold'],
        ComparisonOperator=alarm['ComparisonOperator']
    )
    # update actually creates a new alarm because the name has changed, so
    # we have to manually delete the old one
    client.delete_alarms(AlarmNames=[alarm_name])


if __name__ == '__main__':
    alarm_name, new_alarm_name, new_alarm_threshold = sys.argv[1:3]
    rename_alarm(alarm_name, new_alarm_name, new_alarm_threshold)