ec2 instance toggle

gistfile1.txt

note to self: toggle ec2 instance by one of two instance types using boto3


!/usr/bin/env python3
# -*- coding: utf8 -*-
import os, sys
import datetime
import boto3


THIS_DIR = os.path.dirname(sys.argv[0])
LOG_PATH = os.path.join(THIS_DIR,'odb_content_instance_change.txt')


INSTANCE_ID = 'i-XXX'
TYPE_OPTIONS = ('t2.medium', 't2.large')


def toggle(instance_id: str = INSTANCE_ID) -> None:
    msg = f'instance change for {instance_id}, {datetime.datetime.utcnow()}'

    try:
        ec2 = boto3.client('ec2')

        descr = ec2.describe_instance_attribute(Attribute='instanceType',InstanceId=instance_id)
        current_type = descr['InstanceType']['Value']

        new_type = TYPE_OPTIONS[0]
        if current_type==TYPE_OPTIONS[0]:
            new_type = TYPE_OPTIONS[1]

        msg += f' from {current_type} to {new_type}'

        ec2.stop_instances(InstanceIds=[instance_id])
        waiter = ec2.get_waiter('instance_stopped')
        waiter.wait(InstanceIds=[instance_id])

        ec2.modify_instance_attribute(InstanceId=instance_id,
                                      Attribute='instanceType',
                                      Value=new_type)

        ec2.start_instances(InstanceIds=[instance_id])
    except Exception as e:
        msg += f' failed : {e}'

    msg += '\n'
    with open(LOG_PATH, 'a') as fd:
        fd.write(msg)



if __name__=='__main__':
    main()