AWS Lambda + standalone script to backup all DynamoDB tables.

ddbBackup.py

#!/usr/bin/env python
#based on:
#https://aws.amazon.com/blogs/database/a-serverless-solution-to-schedule-your-amazon-dynamodb-on-demand-backup/
from __future__ import print_function
from datetime import date, datetime, timedelta
import json
import boto3
import time
from botocore.exceptions import ClientError
import os
ddbRegion = os.environ['AWS_DEFAULT_REGION']
ddb = boto3.client('dynamodb', region_name=ddbRegion)

# for deleting old backup. It will search for old backup and will escape deleting last backup days you mentioned in the backup retention
#daysToLookBackup=2
daysToLookBackup= int(os.environ['BackupRetention'])
daysToLookBackupL=daysToLookBackup-1

def lambda_handler(event, context):
    ddbTables = ddb.list_tables()
    print("Backing up tables: ", ddbTables.get("TableNames"))
    for ddbTable in ddbTables.get("TableNames"):
        backup_table(ddbTable)
        delete_old_backups(ddbTable)

def backup_table(ddbTable):
    try:
        #create backup
        backupName = ddbTable
        print('Backup started for: ', backupName)
        ddb.create_backup(TableName=ddbTable,BackupName = backupName)
        print('Backup has been taken successfully for table:', ddbTable)
    except  ClientError as e:
        print(e)
    except ValueError as ve:
        print('error:',ve)
    except Exception as ex:
        print(ex)

def delete_old_backups(ddbTable):
    try:
        #check recent backup
        lowerDate=datetime.now() - timedelta(days=daysToLookBackupL)
        #print('lowerDate: ',lowerDate)
        upperDate=datetime.now()
        #print('upperDate: ',upperDate)
        responseLatest = ddb.list_backups(TableName=ddbTable, TimeRangeLowerBound=datetime(lowerDate.year, lowerDate.month, lowerDate.day), TimeRangeUpperBound=datetime(upperDate.year, upperDate.month, upperDate.day))
        #print('responseLatest:', responseLatest)
        latestBackupCount=len(responseLatest['BackupSummaries'])
        print('Total backup count in recent days:',latestBackupCount)

        deleteupperDate = datetime.now() - timedelta(days=daysToLookBackup)
        #deleteupperDate = datetime.now() + timedelta(days=1)
        #print('deleteupperDate: ',deleteupperDate)
        # TimeRangeLowerBound is the release of Amazon DynamoDB Backup and Restore - Nov 29, 2017
        response = ddb.list_backups(TableName=ddbTable, TimeRangeLowerBound=datetime(2017, 11, 29), TimeRangeUpperBound=datetime(deleteupperDate.year, deleteupperDate.month, deleteupperDate.day))
        #print("response: ",response)
        #check whether latest backup count is more than two before removing the old backup
        if latestBackupCount >= 2:
            for record in response['BackupSummaries']:
                backupArn = record['BackupArn']
                ddb.delete_backup(BackupArn=backupArn)
                print(ddbTable, 'has deleted this backup:', backupArn)
        else:
            print('Recent backup does not meet the deletion criteria')
    except  ClientError as e:
        print(e)
    except ValueError as ve:
        print('error:',ve)
    except Exception as ex:
        print(ex)

def main():
    lambda_handler("test","test")

if __name__ == "__main__":
    main()