Set cache-control max-age for objects in S3 bucket

maxage.py

from boto.s3.connection import S3Connection

# make sure api creds set, KEY/SECRET are just placeholders
connection = S3Connection(KEY, SECRET)
bucket = connection.get_bucket("just.a.test.bucket.really")
keys = bucket.get_all_keys()

for key in keys:
    key.set_metadata('Cache-Control','max-age=43200')
    key.copy(
        key.bucket.name,
        key.name,
        key.metadata,
        preserve_acl=True
    )