Ruby script to add Metadata ( Cache Control and Expires) header to existing S3 Objects

s3_header.rb

require 'rubygems'
require 'aws-sdk'

s3 = AWS::S3.new(
  :access_key_id => 'XXXXXXXXXXXXXXX',
  :secret_access_key => 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX')

bucket = s3.buckets['your_bucket_name']

ten_year_in_seconds = 10 * 365 * 24 * 60 * 60
ten_year_from_now = Time.now + ten_year_in_seconds

# to update an existing object
bucket.objects.each do |obj|
begin
  obj.copy_to(obj.key, 
    :cache_control => "max-age=#{ten_year_in_seconds}", 
    :expires => ten_year_from_now.httpdate)
  rescue Exception => e
    puts "Exception #{e}"
  end
end

# reference : http://www.thehorrors.org.uk/snippets/aws-ruby-s3-set-content-expires-data/