#!/usr/bin/env python3
#----------------------------------------------------------------------------
# Dumps a cloudwatch logs log group to a text file.  The main intention for
# this is to make codebuild-in-packer use cases easier.  The CWL UI is not
# optimized for viewing long logfiles.
#
# Use something like
# AWS_PROFILE=mdr-common-services-gov ./cwlogs.py       \
#    /aws/codebuild/xdr-ec2-threatq-image               \
#    52a94d94-cacb-4cff-8b35-f5aeb39c9c00
#----------------------------------------------------------------------------
import sys
import boto3

if __name__ == "__main__":

    client = boto3.client('logs')

    keepgoing = True
    nextToken = None

    while keepgoing is True:

        kwargs = {
                'logGroupName': sys.argv[1],
                'logStreamName': sys.argv[2],
                'startFromHead': True
        }

        if nextToken is not None:
            kwargs['nextToken'] = nextToken
        elif 'nextToken' in kwargs:
            kwargs.pop('nextToken')

        resp=client.get_log_events(**kwargs)
        if 'events' in resp:
            for e in resp.get('events'):
                print(e.get('message'),end='')
            if len(resp.get('events')) == 0:
                keepgoing = False

        if 'nextForwardToken' in resp:
            nextToken = resp['nextForwardToken']
        else:
            nextToken = None