ec2-lambda-mono-cron.py

import boto3

ec2 = boto3.client("ec2")
ssm = boto3.client("ssm")

# refs https://qiita.com/cumet04/items/5888e037105e6ea5f6bc

def lambda_handler(event, context):
    try:
        targets = target_instances("cron", "true")
        if len(targets) == 0:
            print("No Targets")
        execute(targets, ["false"])
    except Exception as e:
        raise e


def target_instances(tagname, tagvalue):
    resp = ec2.describe_instances(Filters=[{"Name": f"tag:{tagname}", "Values": [tagvalue]}])
    instances = []
    for resv in resp["Reservations"]:
        for i in resv["Instances"]:
            instances.append(i)

    return [instances[0]]  # 先頭の1件を選ぶ


def execute(targets, commands):
    notify_sns_arn = "SOME_NOTIFY_SNS_TOPIC_ARN"
    service_role_arn = "NOTIFY_ROLE_FOR_SSM"
    ids = [i["InstanceId"] for i in targets]
    ssm.send_command(
        InstanceIds=ids,
        DocumentName="AWS-RunShellScript",
        Parameters={"commands": commands, "executionTimeout": ["3600"]},
        ServiceRoleArn=service_role_arn,
        NotificationConfig={
            "NotificationArn": notify_sns_arn,
            "NotificationEvents": ["TimedOut", "Cancelled", "Failed"],
            "NotificationType": "Command",
        },
    )