Lists number of AWS snapshots associated and not associated with an AMI

ec2-snapshot-usage.py

#!/usr/bin/env python3

# ~~~~~~~~~~
# Lists number of snapshots associated and not associated with an AMI
# Requires : AWS PROFILE/REGION/ACCOUNT ID 
# 
# Usage: ./ec2_snapshot_usage.py <aws-profile> <aws-region> <aws-account-id>
# Usage: ./ec2_snapshot_usage.py myawsprofile us-east-1 111111111111
#
# Expected Output:
# Total number of Snapshots: <number>
# Number of Snapshots associated with AMIs: <number>
# Number of Snapshots not associated with AMIs: <number>
# ~~~~~~~~~~

import boto3
import sys
from botocore.exceptions import ClientError

def sortSecond(data):
    return data[1]

def connect_aws(vProfile,vRegion):
    try:
        boto3.setup_default_session(profile_name=vProfile,region_name=vRegion)
        worker = boto3.client('ec2')
        return worker
    except ClientError as e:
        print(e)

def find_ami_snapshots(vWorker):
    try:
        ami_snapshots_list=[]
        response = vWorker.describe_images(Owners=['self',])
        for item in response["Images"]:
            for subitem in item['BlockDeviceMappings']:
                for key,value in subitem.items():
                    if key == 'Ebs':
                        ami_snapshots_list.append(subitem['Ebs'].get("SnapshotId"))
        return ami_snapshots_list
    except ClientError as e:
        print(e)

def find_all_snapshots(vWorker,vAccountId):
    try:
        all_snapshots_list=[]
        response = vWorker.describe_snapshots(OwnerIds=[vAccountId,],)
        for item in response["Snapshots"]:
            all_snapshots_list.append(item["SnapshotId"])
        return all_snapshots_list
    except ClientError as e:
        print(e)

def check_args():
    if len(sys.argv) < 4:
        print(f'Usage: {sys.argv[0]} profile-name region-name account-id')
        exit()

#
# MAIN STARTS HERE
#

if __name__ == '__main__':

    # Check args
    check_args()
    # Get args
    gProfile=sys.argv[1]
    gRegion=sys.argv[2]
    gAccountId=sys.argv[3]
    
    worker_ec2=connect_aws(gProfile,gRegion)
    #
    vAllSnapshots=find_all_snapshots(worker_ec2,gAccountId)
    print(f'Total number of Snapshots: {len(vAllSnapshots)}')
    vUsedSnapshots=find_ami_snapshots(worker_ec2)
    print(f'Number of Snapshots associated with AMIs: {len(vUsedSnapshots)}')
    # 
    stray_snapshots=[]
    for item in vAllSnapshots:
        if not item in vUsedSnapshots:
            stray_snapshots.append(item)
    #for snap in stray_snapshots:
    #  print(f'{snap} is not used by any AMIs ...')
    print(f'Number of Snapshots not associated with AMIs: {len(stray_snapshots)}')