ECS タスク定義ファミリーの古いリビジョンを削除

issue

• タスク定義のリビジョンが溜まりすぎている

対策

• ライフサイクルがないようでまたもやLambda出動

Lambda

lambda_handler Python3.12

import json
import time
import boto3
import botocore

def list_all_task_definitions(ecs_client):
    paginator = ecs_client.get_paginator('list_task_definitions')
    task_definitions = []

    for page in paginator.paginate(status='ACTIVE'):
        task_definitions.extend(page['taskDefinitionArns'])

    return task_definitions

def list_task_definition_revisions(ecs_client, task_definition_family):
    paginator = ecs_client.get_paginator('list_task_definitions')
    revisions = []

    for page in paginator.paginate(familyPrefix=task_definition_family, status='ACTIVE', sort='ASC'):
        revisions.extend(page['taskDefinitionArns'])

    return revisions

def cleanup_old_revisions():
    """すべてのタスク定義ファミリーの古いリビジョンを削除する"""
    ecs_client = boto3.client('ecs')
    task_definitions = list_all_task_definitions(ecs_client)
    task_definition_families = set([arn.split('/')[-1].split(':')[0] for arn in task_definitions])

    for family in task_definition_families:
        revisions = list_task_definition_revisions(ecs_client, family)

        # 最新50個維持
        if len(revisions) > 50:
            revisions_to_delete = revisions[:-50]
            for i, revision in enumerate(revisions_to_delete):
                try:
                    print(f"Deregistering task definition: {revision}")
                    ecs_client.deregister_task_definition(taskDefinition=revision)
                except botocore.exceptions.ClientError as error:
                    if error.response['Error']['Code'] == 'ThrottlingException':
                        print("Throttling exception occurred. Waiting before retrying...")
                        time.sleep(2 ** (i // 30))  # 指数関数的バックオフ
                    else:
                        raise error

def lambda_handler(event, context):
    cleanup_old_revisions()
    return {
        'statusCode': 200,
        'body': json.dumps('Old revisions cleaned up successfully')
    }

EventBridge (CloudWatch Events)

定期実行