Name unnamed EBS snapshots after the image ID and device name to which they're mapped

tag-snapshots-with-ami-id.py

#!/usr/bin/env python

'''
The association between a snapshot and its corresponding AMI and device name is tedious to extract by hand. 

This script names all snapshots "<AMI name> (<AMI id>) <device name>", which makes the associations much easier 
to see. It also makes it easy to find "orphaned" snapshots, i.e. those that aren't associated with extant AMIs.
'''

import boto3

# Your region and profile name will probably differ
session = boto3.Session(profile_name='production')
ec2_client = session.client('ec2', region_name='us-west-2')

regions = ec2_client.describe_regions()['Regions']

for region in regions:
    region_name = region['RegionName']

    ec2_client = session.client('ec2', region_name=region_name)

    print 'Searching %s' % (region_name)

    images = ec2_client.describe_images(Owners=['self'])['Images']

    for image in images:
        for block_device_mapping in image['BlockDeviceMappings']:
            if 'Ebs' in block_device_mapping and \
               'SnapshotId' in block_device_mapping['Ebs']:
                snapshot_tag = "%s (%s) %s" % (
                    image['Name'],
                    image['ImageId'],
                    block_device_mapping['DeviceName'])
                snapshot_id = block_device_mapping['Ebs']['SnapshotId']

                print session.resource('ec2', region_name=region_name)\
                             .Snapshot(snapshot_id).create_tags(
                                 Tags=[{
                                     'Key': 'Name',
                                     'Value': snapshot_tag
                                 }])