最近、勉強でAWS RDSを使用しているのですが、EC2は作業後にちゃんと停止するのですが、RDSの停止忘れのよりコスト増が多発、またメンテンナンスウィンドウの起動で無駄な費用が発生していました。 常に起動してデータベースを使わないのであれば、RDSはメリット少ないかも。
今回はLambda関数を設定して、RDSを自動停止する設定をします。
こちらに従って設定していきます。 Schedule Amazon RDS stop and start using AWS Lambda | AWS Database Blog
IAMポリシーの作成
IAMポリシーを作成します。 起動と停止だけに必要な権限のみを付与します。
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"rds:DescribeDBClusterParameters",
"rds:StartDBCluster",
"rds:StopDBCluster",
"rds:DescribeDBEngineVersions",
"rds:DescribeGlobalClusters",
"rds:DescribePendingMaintenanceActions",
"rds:DescribeDBLogFiles",
"rds:StopDBInstance",
"rds:StartDBInstance",
"rds:DescribeReservedDBInstancesOfferings",
"rds:DescribeReservedDBInstances",
"rds:ListTagsForResource",
"rds:DescribeValidDBInstanceModifications",
"rds:DescribeDBInstances",
"rds:DescribeSourceRegions",
"rds:DescribeDBClusterEndpoints",
"rds:DescribeDBClusters",
"rds:DescribeDBClusterParameterGroups",
"rds:DescribeOptionGroups"
],
"Resource": "*"
}
]
}
これをロールに付与して、Lambda関数を作成します。
Lambda関数を作成
RDSを停止するLambda関数を作成します。
Python 3.9で作成します。ブログそのままですが、あるリージョンの指定したタグを持つRDSを停止するスクリプトになっています。
import boto3 import os import sys import time from datetime import datetime, timezone from time import gmtime, strftime def shut_rds_all(): region=os.environ['REGION'] <-リージョンを入力 key=os.environ['KEY'] <-タグのKEYを入力 value=os.environ['VALUE'] <-タグのVALUEを入力 client = boto3.client('rds', region_name=region) response = client.describe_db_instances() v_readReplica=[] for i in response['DBInstances']: readReplica=i['ReadReplicaDBInstanceIdentifiers'] v_readReplica.extend(readReplica) for i in response['DBInstances']: #The if condition below filters aurora clusters from single instance databases as boto3 commands defer to stop the aurora clusters. if i['Engine'] not in ['aurora-mysql','aurora-postgresql']: #The if condition below filters Read replicas. if i['DBInstanceIdentifier'] not in v_readReplica and len(i['ReadReplicaDBInstanceIdentifiers']) == 0: arn=i['DBInstanceArn'] resp2=client.list_tags_for_resource(ResourceName=arn) #check if the RDS instance is part of the Auto-Shutdown group. if 0==len(resp2['TagList']): print('DB Instance {0} is not part of autoshutdown'.format(i['DBInstanceIdentifier'])) else: for tag in resp2['TagList']: #If the tags match, then stop the instances by validating the current status. if tag['Key']==key and tag['Value']==value: if i['DBInstanceStatus'] == 'available': client.stop_db_instance(DBInstanceIdentifier = i['DBInstanceIdentifier']) print('stopping DB instance {0}'.format(i['DBInstanceIdentifier'])) elif i['DBInstanceStatus'] == 'stopped': print('DB Instance {0} is already stopped'.format(i['DBInstanceIdentifier'])) elif i['DBInstanceStatus']=='starting': print('DB Instance {0} is in starting state. Please stop the cluster after starting is complete'.format(i['DBInstanceIdentifier'])) elif i['DBInstanceStatus']=='stopping': print('DB Instance {0} is already in stopping state.'.format(i['DBInstanceIdentifier'])) elif tag['Key']!=key and tag['Value']!=value: print('DB instance {0} is not part of autoshutdown'.format(i['DBInstanceIdentifier'])) elif len(tag['Key']) == 0 or len(tag['Value']) == 0: print('DB Instance {0} is not part of auroShutdown'.format(i['DBInstanceIdentifier'])) elif i['DBInstanceIdentifier'] in v_readReplica: print('DB Instance {0} is a Read Replica. Cannot shutdown a Read Replica instance'.format(i['DBInstanceIdentifier'])) else: print('DB Instance {0} has a read replica. Cannot shutdown a database with Read Replica'.format(i['DBInstanceIdentifier'])) response=client.describe_db_clusters() for i in response['DBClusters']: cluarn=i['DBClusterArn'] resp2=client.list_tags_for_resource(ResourceName=cluarn) if 0==len(resp2['TagList']): print('DB Cluster {0} is not part of autoshutdown'.format(i['DBClusterIdentifier'])) else: for tag in resp2['TagList']: if tag['Key']==key and tag['Value']==value: if i['Status'] == 'available': client.stop_db_cluster(DBClusterIdentifier=i['DBClusterIdentifier']) print('stopping DB cluster {0}'.format(i['DBClusterIdentifier'])) elif i['Status'] == 'stopped': print('DB Cluster {0} is already stopped'.format(i['DBClusterIdentifier'])) elif i['Status']=='starting': print('DB Cluster {0} is in starting state. Please stop the cluster after starting is complete'.format(i['DBClusterIdentifier'])) elif i['Status']=='stopping': print('DB Cluster {0} is already in stopping state.'.format(i['DBClusterIdentifier'])) elif tag['Key'] != key and tag['Value'] != value: print('DB Cluster {0} is not part of autoshutdown'.format(i['DBClusterIdentifier'])) else: print('DB Instance {0} is not part of auroShutdown'.format(i['DBClusterIdentifier'])) def lambda_handler(event, context): shut_rds_all()
これをEventBridgeで定期実行します。 cronは午前3時に起動するように設定しました。
cron(0 18 * * ? *)
これで設定できました。RDSが停止していれば、ログはFailが並びます...
課金の状況
RDSを立ち上げることが月に数回しかないので、毎日失敗しています。
毎回実行時間は1秒以下。 課金額は0円でした。
