AWS EBS - Find unused snapshots

README.md

This script can help you find and remove unused AWS snapshots and volumes.

There is hardcoded list of regions that it searches, adjust the value to suit your needs.

Use snapshot.py snapshot-report to generate report.csv containing information about all snapshots.

snapshot.py snapshot-cleanup lets you interactively delete snapshot if it finds it is referencing unexisting resources.

./snapshots.py --help
Usage: snapshots.py [OPTIONS] COMMAND [ARGS]...

  Helper commands for Snapshots management.

Options:
  --help  Show this message and exit.

Commands:
  snapshot-cleanup  Find and delete unreferenced snapshots.
  snapshot-delete   Delete single snapshot by id.
  snapshot-report   Find unreferenced snapshots.
  volume-cleanup    Find and delete unused volumes.

snapshots.py

#!/usr/local/bin/python3
import csv
import re
from collections import OrderedDict
from pprint import pprint

import boto3
import click
from botocore.exceptions import ClientError

regions = ['us-west-1', 'eu-central-1']


ec2 = None
exists_icon = '✅'
not_exists_icon = '❌'


@click.group()
def cli():
    '''
    Helper commands for Snapshots management.
    '''
    pass


@cli.command()
def snapshot_report():
    '''
    Find unreferenced snapshots.
    '''
    global ec2
    with open('report.csv', 'w') as csv_file:
        csv_writer = csv.writer(csv_file, delimiter=',', quotechar='"', quoting=csv.QUOTE_MINIMAL)
        csv_writer.writerow([
            'id',
            'volume_id', 
            'volume_exists', 
            'ami_id',
            'ami_exists',
            'instance_id',
            'instance_exists',
            'size',
            'start_time',
            'description' ])
        for region in regions:
            ec2 = boto3.client('ec2', region_name=region)
            for snapshot in get_snapshots():
                csv_writer.writerow([
                    snapshot['id'],
                    snapshot['volume_id'], 
                    snapshot['volume_exists'], 
                    snapshot['ami_id'],
                    snapshot['ami_exists'],
                    snapshot['instance_id'],
                    snapshot['instance_exists'],
                    str(snapshot['size']) + 'gb',
                    str(snapshot['start_time']),
                    snapshot['description']])

@cli.command()
def snapshot_cleanup():
    '''
    Find and delete unreferenced snapshots.
    '''
    global ec2
    print('{:22} {:23} {:23} {:23} {:>7} {:25} {:30}'.format('snapshot id', 'volume id', 'ami id',
                                                             'instance id', 'size', 'start time', 'description'))

    for region in regions:
        ec2 = boto3.client('ec2', region_name=region)
        print('region={}'.format(region))
        for snapshot in get_snapshots():
            volume_exists = exists_icon if snapshot['volume_exists'] else not_exists_icon
            ami_exists = exists_icon if snapshot['ami_exists'] else not_exists_icon
            instance_exists = exists_icon if snapshot['instance_exists'] else not_exists_icon
            print('{:22} {:22} {:22} {:22} {:>7} {:25} {:30}'.format(
                snapshot['id'],
                snapshot['volume_id'] + volume_exists,
                snapshot['ami_id'] + ami_exists,
                snapshot['instance_id'] + instance_exists,
                str(snapshot['size']) + 'gb',
                str(snapshot['start_time']),
                snapshot['description']
            ))
            if not snapshot['volume_exists'] and not snapshot['ami_exists'] and not snapshot['instance_exists'] and click.confirm('Delete?', default=True):
                ec2.delete_snapshot(SnapshotId=snapshot['id'])


@cli.command()
def volume_cleanup():
    '''
    Find and delete unused volumes.
    '''
    global ec2
    print('{:23} {:20} {:>7} {:10} {:23}'.format(
        'volume id', 'status', 'size', 'created', 'snapshot id'))

    for region in regions:
        ec2 = boto3.client('ec2', region_name=region)
        print('region={}'.format(region))
        for volume in get_available_volumes():
            snapshot_exists = exists_icon if volume['snapshot_exists'] else not_exists_icon
            print('{:23} {:20} {:>7} {:10} {:22}'.format(
                volume['id'],
                volume['status'],
                str(volume['size']) + 'gb',
                volume['create_time'].strftime('%Y-%m-%d'),
                volume['snapshot_id'] + snapshot_exists

            ))
            if not volume['snapshot_exists']:
                print('Tags:')
                print('  '+('\n  '.join(['{}={}'.format(click.style(key, fg='blue'), tag)
                                         for key, tag in volume['tags'].items()])))
                if click.confirm('Delete?', default=True):
                    ec2.delete_volume(VolumeId=volume['id'])


@cli.command()
@click.argument('snapshot_id')
def snapshot_delete(snapshot_id):
    '''
    Delete single snapshot by id.
    '''
    try:
        ec2.delete_snapshot(SnapshotId=snapshot_id)
        print('Deleted ' + snapshot_id)
    except ClientError as e:
        print('Failed to delete ' + snapshot_id)
        print(e)


def get_snapshots():
    '''
    Get all snapshots.
    '''
    for snapshot in ec2.describe_snapshots(OwnerIds=['self'])['Snapshots']:
        instance_id, image_id = parse_description(snapshot['Description'])
        yield {
            'id': snapshot['SnapshotId'],
            'description': snapshot['Description'],
            'start_time': snapshot['StartTime'],
            'size': snapshot['VolumeSize'],
            'volume_id': snapshot['VolumeId'],
            'volume_exists': volume_exists(snapshot['VolumeId']),
            'instance_id': instance_id,
            'instance_exists': instance_exists(instance_id),
            'ami_id': image_id,
            'ami_exists': image_exists(image_id),
        }


def get_available_volumes():
    '''
    Get all volumes in 'available' state. (Volumes not attached to any instance)
    '''
    for volume in ec2.describe_volumes(Filters=[{'Name': 'status', 'Values': ['available']}])['Volumes']:
        yield {
            'id': volume['VolumeId'],
            'create_time': volume['CreateTime'],
            'status': volume['State'],
            'size': volume['Size'],
            'snapshot_id': volume['SnapshotId'],
            'snapshot_exists': str(snapshot_exists(volume['SnapshotId'])),
            'tags': OrderedDict(sorted([(tag['Key'], tag['Value']) for tag in volume['Tags']])),
        }


def snapshot_exists(snapshot_id):
    if not snapshot_id:
        return ''
    try:
        ec2.describe_snapshots(SnapshotIds=[snapshot_id])
        return True
    except ClientError:
        return False


def volume_exists(volume_id):
    if not volume_id:
        return False
    try:
        ec2.describe_volumes(VolumeIds=[volume_id])
        return True
    except ClientError:
        return False


def instance_exists(instance_id):
    if not instance_id:
        return ''
    try:
        return len(ec2.describe_instances(InstanceIds=[instance_id])['Reservations']) != 0
    except ClientError:
        return False


def image_exists(image_id):
    if not image_id:
        return ''
    try:
        return len(ec2.describe_images(ImageIds=[image_id])['Images']) != 0
    except ClientError:
        return False


def parse_description(description):
    regex = r"^Created by CreateImage\((.*?)\) for (.*?) "
    matches = re.finditer(regex, description, re.MULTILINE)
    for matchNum, match in enumerate(matches):
        return match.groups()
    return '', ''


if __name__ == '__main__':
    cli()

Hi,

I'm getting following error while run script from Linux. Could someone help to fix?

File "snap.py", line 15
SyntaxError: Non-ASCII character '\xe2' in file snap.py on line 15, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details

Thanks!

There seems to be an issue with the regex in parse_description(description) since it is not returning the ami-id out of the "Created by CreateImage(i-01010101010101010) for ami-01010101010101010" string in the snapshot description. Hence the script will propose to delete a snapshot which has an AMI still registered thus rendering the remaining image useless without it's corresponding snapshot...

Please check the regex.
regex = r"^Created by CreateImage\((.*?)\) for (.*)"

A fixed parse_description which handles more 'created by' situations

def parse_description(description):
    if "from" in description:
        regex = r"^Created by CreateImage\((.*?)\) for (.*)(?: from .*)"
    else:
        regex = r"^Created by CreateImage\((.*?)\) for (ami.*)"
    matches = re.finditer(regex, description, re.MULTILINE)
    for matchNum, match in enumerate(matches):
        return match.groups()
    return '', ''

One question - How can I run this script for several accounts in an org ?