cdnify_assets.rb

# CDN-ify Assets
# 
# This script will traverse all the objects in an S3 bucket and set ACLs and 
# cache headers as appropriate for CDN (CloudFront) distribution. Specifically, 
# it sets them to expire 10 years from now (far-future expiration) and ACLs to 
# be publicly readable.
# 
# Use this if you have an S3 bucket full of assets that didn't get proper settings
# set when you uploaded them, and you need an easy way to fix them now.
# 
# Feel free to run this multiple times against the same bucket. It sets metadata
# on the CDN-ified objects and will not re-cdn-ify objects that have already been
# done.
# 
# Usage: 
# ruby cdnify_assets.rb my_aws_access_key my_aws_secret_access_key my_fancy_bucket

require 'rubygems'
require 'aws/s3'

STDOUT.sync = true

access_key_id, secret_access_key, bucket_name = ARGV

c = AWS::S3::Base.establish_connection!(
 :access_key_id => access_key_id,
 :secret_access_key => secret_access_key
)

bucket = AWS::S3::Bucket.find(bucket_name)

puts "Found bucket '#{bucket_name}'"
puts "#{bucket.objects.size} objects found"

if bucket.objects.size > 0
  puts "Updating..."

  bucket.objects.each do |o|
    
    if o.metadata[:cdnified_at]
      print '.'
    else
      o.metadata[:cdnified_at] = Time.now.httpdate
      o.cache_control = 'max-age=315360000, public'
      o.expires = (Time.now + 315360000).httpdate
      o.save({:access => :public_read})
      print '+'
    end
  end
end

puts "\nFinished"