使用boto将文件从ec2传输到s3时出错

我按照这个程序link将我的mongodump上传到s3.

bash脚本

#!/bin/sh

MONGODB_SHELL='/usr/bin/mongo'

DUMP_UTILITY='/usr/bin/mongodump'
DB_NAME='amicus'

date_now=`date +%Y_%m_%d_%H_%M_%S`
dir_name='db_backup_'${date_now}
file_name='db_backup_'${date_now}'.bz2'

log() {
    echo $1
}

do_cleanup(){
    rm -rf db_backup_2010* 
    log 'cleaning up....'
}

do_backup(){
    log 'snapshotting the db and creating archive' && 
    ${MONGODB_SHELL} admin fsync_lock.js && 
    ${DUMP_UTILITY} -d ${DB_NAME} -o ${dir_name} && tar -jcf $file_name ${dir_name}
    ${MONGODB_SHELL} admin unlock.js && 
    log 'data backd up and created snapshot'
}

save_in_s3(){
    log 'saving the backup archive in amazon S3' && 
    python aws_s3.py set ${file_name} && 
    log 'data backup saved in amazon s3'
}

do_backup && save_in_s3 && do_cleanup

aws_s3.py

ACCESS_KEY=''
SECRET=''
BUCKET_NAME='s3:///s3.amazonaws.com/database-backup' #note that you need to create this bucket first

from boto.s3.connection import S3Connection
from boto.s3.key import Key

def save_file_in_s3(filename):
    conn = S3Connection(ACCESS_KEY,SECRET)
    bucket = conn.get_bucket(BUCKET_NAME)
    k = Key(bucket)
    k.key = filename
    k.set_contents_from_filename(filename)

def get_file_from_s3(filename):
    conn = S3Connection(ACCESS_KEY,SECRET)
    bucket = conn.get_bucket(BUCKET_NAME)
    k = Key(bucket)
    k.key = filename
    k.get_contents_to_filename(filename)

def list_backup_in_s3():
    conn = S3Connection(ACCESS_KEY,SECRET)
    bucket = conn.get_bucket(BUCKET_NAME)
    for i,key in enumerate(bucket.get_all_keys()):
        print "[%s] %s" % (i,key.name)

def delete_all_backups():
    #FIXME: validate filename exists
    conn = S3Connection(ACCESS_KEY,key in enumerate(bucket.get_all_keys()):
        print "deleting %s" % (key.name)
        key.delete()

if __name__ == '__main__':
    import sys
    if len(sys.argv) < 3:
        print 'Usage: %s 

Traceback (most recent call last):
  File "aws_s3.py",line 42,in