Functions
def	get_parser ()

def	cleanup_temp_file (tmp_file)

def	return_presigned_url (s3_client, object_key)

def	return_pdf_content (s3_client, s3_file_name)

def	main (argv)

def	run ()

Variables
tuple	format

	LOGGER = logging.getLogger(__name__)

	logging_handler = logging.StreamHandler()

string	AWS_REGION = 'us-east-1'

string	S3_STMNT_BUCKET = "homecu.stmnts"

int	MAX_RETRIES_DEFAULT = 2

	PRESIGN_URL_EXPIRATION_SECONDS

Detailed Description

Retrieve eStatement from AWS S3

Only the correct content is streamed to stdout. Any error must be
streamed down to stderr descriptor.

On failure, this script retries aws s3 api call for the number provided with
--s3-retries option argument. Default is MAX_RETRIES_DEFAULT.

Script Output:
    Status code:
0, if no error
1, if any error, exceptions

    Content (see usage for more detail):
PDF binary content, OR
S3 Presigned URL - has a short expiration duration
               (ENV: AWS_S3_PRESIGNURL_EXPIRATION_SECONDS;
               default: 120 seconds)

References:
[1] https://docs.aws.amazon.com/cli/latest/reference/s3/presign.html
[2] https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3.html#S3.Client.generate_presigned_url

Function Documentation

◆ cleanup_temp_file()

def EStateGetFromS3.cleanup_temp_file ( tmp_file )

Cleanup temporarily downloaded estatement file

Definition at line 90 of file EStateGetFromS3.py.

 def cleanup_temp_file(tmp_file):
     """Cleanup temporarily downloaded estatement file"""
     if os.path.exists(tmp_file):
         os.remove(tmp_file)
 
 

◆ get_parser()

def EStateGetFromS3.get_parser ( )

Prepare argument parser.

Returns:
    parser -- ArgumentParser object

Definition at line 63 of file EStateGetFromS3.py.

 def get_parser():
     """Prepare argument parser.
 
     Returns:
         parser -- ArgumentParser object
     """
     parser = ArgumentParser(
         description=("Get PDF EStatement Content from S3 (buffered"
         "binary content OR s3 presigned url).")
     )
 
     parser.add_argument("-f", "--file-estmnt",
                         help="Full path to estatement file for this period",
                         required=True
                         )
 
     parser.add_argument("-p", "--presignedurl", action = "store_true",
                         help=("stream s3 presign url to stdout; "
                               "otherwise streams actual pdf content")
                         )
     parser.add_argument("-r", "--s3-retries",
                         help="Maximum number of retries on failure",
                         type=int,
                         default=MAX_RETRIES_DEFAULT)
     return parser
 
 

◆ main()

def EStateGetFromS3.main ( argv )

Retrieve eStatement from AWS S3 estatement storing bucket

Definition at line 133 of file EStateGetFromS3.py.

 def main(argv):
     """Retrieve eStatement from AWS S3 estatement storing bucket"""
 
     parser=get_parser()
     args = parser.parse_args(argv)
     success_status = False
 
     file_parts = args.file_estmnt.split("/")[1:]
 
     if len(file_parts) != 7:
         LOGGER.error(("Requested path to estatement '%s' is invalid; "
                      "Eg. correct path: "
                      "'/home/CUCODE/stmnt/pdf/yyyymmM/1/1XXXX.pdf" %
                      args.file_estmnt))
         return success_status
 
     cucode = file_parts[1].strip()
     s3_file_name = os.path.join(file_parts[1],
                                 file_parts[2],
                                 file_parts[3],
                                 file_parts[4],
                                 file_parts[5],
                                 file_parts[6])
     max_retries = args.s3_retries
     tries = 0
 
     while tries < max_retries and not success_status:
         tries += 1
         try:
             client = boto3.client('s3', region_name=AWS_REGION)
 
             if args.presignedurl:
                 return_presigned_url(client, s3_file_name)
             else:
                 return_pdf_content(client, s3_file_name)
 
         except Exception as e:
             LOGGER.error(("[%s] Estatement Retrieval from AWS S3 failed "
                           "(try# %s/%s): %s") %  (cucode.upper(), tries,
                                                   max_retries, e))
         else:
             success_status = True
 
     return success_status
 
 

◆ return_pdf_content()

def EStateGetFromS3.return_pdf_content	(	s3_client,
		s3_file_name
	)

Download pdf from S3 and return stream content to stdout

Definition at line 116 of file EStateGetFromS3.py.

 def return_pdf_content(s3_client, s3_file_name):
     """Download pdf from S3 and return stream content to stdout"""
     tmp_file = os.path.join("/tmp", s3_file_name.replace("/", "_"))
     try:
         # download pdf object from S3
         s3_client.download_file(S3_STMNT_BUCKET, s3_file_name, tmp_file)
     except Exception as e:
         cleanup_temp_file(tmp_file)
         LOGGER.error("Estatement `%s` download failed." % s3_file_name)
         raise
     else:
         # return pdf content
         with open(tmp_file, 'rb') as f_read:
            sys.stdout.buffer.write(f_read.read())
         cleanup_temp_file(tmp_file)
 
 

◆ return_presigned_url()

def EStateGetFromS3.return_presigned_url	(	s3_client,
		object_key
	)

Return an object's pre-signed

Definition at line 96 of file EStateGetFromS3.py.

 def return_presigned_url(s3_client, object_key):
     """Return an object's pre-signed"""
     url = ""
     try:
         url = s3_client.generate_presigned_url(
             ClientMethod='get_object',
             Params={
                 "Bucket" : S3_STMNT_BUCKET,
                 "Key" : object_key
             },
             ExpiresIn=PRESIGN_URL_EXPIRATION_SECONDS
     )
     except Exception as e:
         LOGGER.error("Estatement `%s` download failed." % object_key)
         raise
     else:
         # return s3 presigned url
         print(url)
 
 

◆ run()

def EStateGetFromS3.run ( )

Script entrypoint

Definition at line 179 of file EStateGetFromS3.py.

 def run():
     """Script entrypoint"""
     sys.exit(main(sys.argv[1:]))
 
 

Variable Documentation

◆ format

tuple EStateGetFromS3.format

Initial value:

1 = ("[%(levelname)-5s] %(asctime)-15s ({}|%(funcName)s|%(lineno)d) "

2 ":: %(message)s").format(__file__)

Definition at line 36 of file EStateGetFromS3.py.

◆ PRESIGN_URL_EXPIRATION_SECONDS

EStateGetFromS3.PRESIGN_URL_EXPIRATION_SECONDS