lambdafolder.py

import boto3
import os
import json
from datetime import datetime, timedelta
''' Global Variable defined for Bucket, Object and Filenames '''
SRC_BUCKET_NAME = 'bucket-name'
DEV_DST_BUCKET_NAME = 'bucket-name'
INT_DST_BUCKET_NAME = 'bucket-name'
TST_DST_BUCKET_NAME = 'bucket-name'


def download_s3_file(myfile):
    s3_source = boto3.client('s3')
    # Splitting Myfile into different segments,folders and files
    items = myfile.split('/')
    fparent = items[0]
    ffile = items[1]
    folder_name = fparent
    # take the folder with file and save it to '/tmp/file',only files will be saved in /tmp
    s3_source.download_file(
        SRC_BUCKET_NAME, folder_name+'/'+ffile, '/tmp/'+ffile)


def upload_s3_file(myfile):
    sts = boto3.client('sts')
    # DEV
    sts_result_dev = sts.assume_role(
        RoleArn='arn:aws:iam::'+'acctid'+':role/Role-Name', RoleSessionName='session')
    s3_dest_dev = boto3.client('s3', aws_access_key_id=sts_result_dev['Credentials']['AccessKeyId'],
                               aws_secret_access_key=sts_result_dev['Credentials']['SecretAccessKey'],
                               aws_session_token=sts_result_dev['Credentials']['SessionToken'])
    items = myfile.split('/')
    fparent = items[0]
    ffile = items[1]
    folder_name = fparent
    s3_dest_dev.put_object(Bucket=DEV_DST_BUCKET_NAME, Key=(folder_name+'/'))
    s3_dest_dev.upload_file(
        '/tmp/'+ffile, DEV_DST_BUCKET_NAME, folder_name+'/'+ffile)
    #To trigger SNS Message  only Once Logic
    objs = s3_dest_dev.list_objects_v2(Bucket=DEV_DST_BUCKET_NAME,Prefix=folder_name)
    message = 'List of Objects \n'
    fileCount = objs['KeyCount']
    print(fileCount)
    if fileCount == 11:
        for object in objs['Contents']:
            message = message + object['Key'] + '\n'
        response = sns.publish(
            TopicArn ='arn:aws:sns:us-east-1:a/c no.:my_sns',
            Message = message
            )

    # INT
    sts_result_int = sts.assume_role(
        RoleArn='arn:aws:iam::'+'acctid'+':role/Role-Name', RoleSessionName='session')
    s3_dest_int = boto3.client('s3', aws_access_key_id=sts_result_int['Credentials']['AccessKeyId'],
                               aws_secret_access_key=sts_result_int['Credentials']['SecretAccessKey'],
                               aws_session_token=sts_result_int['Credentials']['SessionToken'])
    items = myfile.split('/')
    fparent = items[0]
    ffile = items[1]
    folder_name = fparent
    s3_dest_int.put_object(Bucket=INT_DST_BUCKET_NAME, Key=(folder_name+'/'))
    s3_dest_int.upload_file(
        '/tmp/'+ffile, INT_DST_BUCKET_NAME, folder_name+'/'+ffile)

    # TST
    sts_result_tst = sts.assume_role(
        RoleArn='arn:aws:iam::'+'acctid'+':role/Role-Name', RoleSessionName='session')
    s3_dest_tst = boto3.client('s3', aws_access_key_id=sts_result_tst['Credentials']['AccessKeyId'],
                               aws_secret_access_key=sts_result_tst['Credentials']['SecretAccessKey'],
                               aws_session_token=sts_result_tst['Credentials']['SessionToken'])

    items = myfile.split('/')
    fparent = items[0]
    ffile = items[1]
    folder_name = fparent
    s3_dest_tst.put_object(Bucket=TST_DST_BUCKET_NAME, Key=(folder_name+'/'))
    s3_dest_tst.upload_file(
        '/tmp/'+ffile, TST_DST_BUCKET_NAME, folder_name+'/'+ffile)


def lambda_handler(event, context):
    try:
        sns = boto3.client('sns')
        print(event)
        myfile = event['Records'][0]['s3']['object']['key']
        print(myfile)
        #This Would trigger SNS Notifications on every event,say 10 events have 10 diff. notification,Not Good practice
        response = sns.publish(
            TopicArn ='arn:aws:sns:us-east-1:a/c number:sns_name',
            Message = myfile,
            )
        download_s3_file(myfile)
        upload_s3_file(myfile)
    except Exception as e:
        print(e)

        
        
 ##Remember to Increase the Lambda Basic Execution Time to let's say 10 mins,as there are multiple file transfer b/w several a/c's.
## Adding SNS Topic To trigger Lambda Function
def lambda_handler(event, context):
    try:
        key =json.loads(event['Records'][0]['Sns']['Message'])
        myfile =key['Records'][0]['s3']['object']['key']
        print(myfile)
        download_s3_file(myfile)
        upload_s3_file(myfile)
    except Exception as e:
        print(e)