A simple script that allows you to update massively Content-Type for files on an S3 bucket.
This script is able to:

• Browse recursively a bucket
• Perform action only on files matching specific prefix
• Auto-detect type of file depending on its extension

Obviously, you can add any extension you want to the function update_md to handle more if needed.#!/usr/bin/env python
# -*- coding: utf-8 -*-
import os, re, sys
import boto
from boto.s3.connection import S3Connection
from boto.s3.key import Key

Variables

AWS_ACCESS_KEY_ID = 'YOUR_AWS_ACCESS_KEY_ID'

AWS_SECRET_ACCESS_KEY = 'YOUR_AWS_SECRET_ACCESS_KEY'

AWS_BUCKET_NAME = 'YOUR_BUCKET_NAME'

Function to update MetaData

def update_md(k):

"""

Update the metadata with an existing object.

"""

# Get extension

ext = k.name.split('.')[-1]

if ext in ['bmp','BMP']:

metadata = {'Content-Type':'image/bmp'}

elif ext in ['jpg','jpeg','JPG','JPEG']:

metadata = {'Content-Type':'image/jpeg'}

elif ext in ['gif','GIF']:

metadata = {'Content-Type':'image/gif'}

elif ext in ['png','PNG']:

metadata = {'Content-Type':'image/png'}

elif ext in ['pdf','PDF']:

metadata = {'Content-Type':'application/pdf'}

elif ext in ['txt','TXT']:

metadata = {'Content-Type':'text/plain'}

elif ext in ['zip','ZIP']:

metadata = {'Content-Type':'application/zip'}

else:

return

# If not same type -- update

if metadata['Content-Type'] != akey.content_type:

akey.copy(AWS_BUCKET_NAME, k.name, metadata, preserve_acl=True)

return k

Main function

if name == 'main':

# Connect to S3

conn = boto.connect_s3(AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY)

b = conn.get_bucket(AWS_BUCKET_NAME)

# Select files to parse (prefix can be specified)
rs = b.list(prefix="")

# Browse files
for k in rs:
    print k.name
    akey = b.get_key(k.name)
    # Print type before
    print "Before:",akey.content_type
    try:
        k = update_md(k)
        akey = b.get_key(k.name)
        print "After: ",akey.content_type
    except Exception,e:
        print "Content-Type not handled by this script"

print "Script finished!"