Download file from S3

download_file.py

#! /usr/bin/python

from boto.utils import get_instance_metadata
import boto
import argparse, logging

def parsed_args():
    # parse cmd line args
    parser = argparse.ArgumentParser(description='Download file from S3')
    parser.add_argument('--bucket',
                        help='Name of S3 bucket to download from')
    parser.add_argument('--file',
                        help='Name of file to download')
    return parser.parse_args();

def main():
  logging.info('Fetching file from S3...')
  
  args = parsed_args();
  conn = boto.s3.connect_to_region(current_region())
  bucket = conn.get_bucket(args.bucket)
  logging.info('Iterating over bucket %s contents...' % args.bucket)
  
  for l in bucket.list():
      keyString = str(l.key)
      logging.info('Found file %s' % keyString)
      
      if keyString == args.file:
          logging.info('Downloading %s' % keyString)
          l.get_contents_to_filename('/tmp/'+keyString[keyString.rfind('/'):])

def current_zone():
  metadata = get_instance_metadata()
  return metadata['placement']['availability-zone']

def current_region():
  zone = current_zone()
  return zone[:-1]  

if __name__ == '__main__':
  logging.getLogger().setLevel(logging.INFO)
  main()