Simple S3 utils - copy bucket to bucket (See related posts)

a = AmazoneS3Asset.new
a.copy_over_bucket("myapp_production", "myapp_production")

require 'aws/s3'
require 'mechanize'

class AmazonS3Asset
  
  include AWS::S3
  S3ID = "your s3 id"
  S3KEY = "your s3 key"
  
  def initialize
    puts "connecting..."
    AWS::S3::Base.establish_connection!(
      :access_key_id     => S3ID,
      :secret_access_key => S3KEY
    )
  end

  def delete_key(bucket, key)
    if exists?(bucket, key) 
      S3Object.delete key, bucket
    end
  end
  
  def empty_bucket(bucket)
    bucket_keys(bucket).each do |k|
      puts "deleting #{k}"
      delete_key(bucket,k)
    end
  end
  
  def bucket_keys(bucket)
    b = Bucket.find(bucket)
    b.objects.collect {|o| o.key}
  end

  def copy_over_bucket(from_bucket, to_bucket)
    puts "Replacing #{to_bucket} with contents of #{from_bucket}"
    #delete to_bucket
    empty_bucket(to_bucket)
    bucket_keys(from_bucket).each do |k|
      copy_between_buckets(from_bucket, to_bucket, k)
    end
  end
  
  def copy_between_buckets(from_bucket, to_bucket, from_key, to_key = nil)
    if exists?(from_bucket, from_key)
      to_key = from_key if to_key.nil?
      puts "Copying #{from_bucket}.#{from_key} to #{to_bucket}.#{to_key}"
      url = "http://s3.amazonaws.com/#{from_bucket}/#{from_key}"
      filename = download(url)
      store_file(to_bucket,to_key,filename)
      File.delete(filename)
      return "http://s3.amazonaws.com/#{to_bucket}/#{to_key}"
    else
      puts "#{from_bucket}.#{from_key} didn't exist"
      return nil
    end
  end

  def store_file(bucket, key, filename)
     puts "Storing #{filename} in #{bucket}.#{key}"
     S3Object.store(
      key,
      File.open(filename),
      bucket,
      :access => :public_read
      )
  end

  def download(url, save_as = nil)
    if save_as.nil?
      Dir.mkdir("amazon_s3_temp") if !File.exists?("amazon_s3_temp")
      save_as = File.join("amazon_s3_temp",File.basename(url))
    end
    begin
      puts "Saving #{url} to #{save_as}"
      agent = WWW::Mechanize.new {|a| a.log = Logger.new(STDERR) }
      img = agent.get(url)
      img.save_as(save_as)
      return save_as
    rescue
      raise "Failed on " + url + "  " + save_as
    end
  end

  def exists?(bucket,key)
    begin
      res = S3Object.find key, bucket
    rescue 
      res = nil
    end
    return !res.nil?
  end
      
end