lambda function to export all logs from cloudWatch logGroup to s3Bucket. PS. Remember to set perms accordingly and to rename logGroupName, destinationPrefix, etc...

exportToS3.py

"""This is an function to export ALL logs from a logGroup to a s3 bucket.

Usage::
    Just create a new lambda function and paste this code.
    I also created a scheduled event with rate(1 hour)

"""
from __future__ import print_function
import boto3
import botocore.exceptions
import hmac
import hashlib
import base64
import json
import uuid
import logging
from datetime import tzinfo, timedelta
import datetime

client = None

logger = logging.getLogger()
logger.setLevel(logging.INFO)

class FixedOffset(tzinfo):
    def __init__(self, offset):
        self.__offset = timedelta(hours=offset)
        self.__dst = timedelta(hours=offset-3)
        self.__name = ''

    def utcoffset(self, dt):
        return self.__offset

    def tzname(self, dt):
        return self.__name

    def dst(self, dt):
        return self.__dst

def exportToS3(fromTime, to):
    try:
        resp = client.create_export_task(
            taskName='LogTask_'+datetime.datetime.now(FixedOffset(-3)).strftime("%Y-%m-%d %H:%M:%S"),
            logGroupName='/aws/lambda/Something',
            fromTime=int(round(fromTime.timestamp() * 1000)),
            to=int(round(to.timestamp() * 1000)),
            destination='s3BucketName',
            destinationPrefix='somePreffixConfiguredOnS3Bucket'
            )
    except Exception as e:
        #print(e)
        logger.error(e)
        return None, "Unknown error"
    return resp, None

def lambda_handler(event, context):
    global client
    if client == None:
        client = boto3.client('logs')

    #print(event)

    fromTime = datetime.datetime.now(FixedOffset(-3)) - datetime.timedelta(minutes=60)
    to = datetime.datetime.now(FixedOffset(-3))
  
    resp, msg = exportToS3(fromTime, to)
    if msg != None:
        # return {'status': 'fail', 'msg': msg}
        logger.info('failed to export logs to s3')
        raise Exception(msg)

    logger.info('successfully exported cloudWatchLogs...')
    return {'status': 'success'}