How to copy file across buckets using aws-s3 or aws-sdk gem in ruby on rails

Question

The aws-s3 documentation says:

  # Copying an object
  S3Object.copy 'headshot.jpg', 'headshot2.jpg', 'photos'

But how do I copy heashot.jpg from the photos bucket to the archive bucket for example

Thanks!

Deb

Answer 1

Multiple images could easily be copied using aws-sdk gem as follows:

require 'aws-sdk'

image_names = ['one.jpg', 'two.jpg', 'three.jpg', 'four.jpg', 'five.png', 'six.jpg']
Aws.config.update({
    region: "destination_region", 
    credentials: Aws::Credentials.new('AWS_ACCESS_KEY_ID', 'AWS_SECRET_ACCESS_KEY')
})
image_names.each do |img|
    s3 = Aws::S3::Client.new()
    resp = s3.copy_object({
      bucket: "destinationation_bucket_name", 
      copy_source: URI.encode_www_form_component("/source_bucket_name/path/to/#{img}"), 
      key: "path/where/to/save/#{img}" 
    })      
end

If you have too many images, it is suggested to put the copying process in a background job.

Answer 2

AWS-SDK gem. S3Object#copy_to

Copies data from the current object to another object in S3.
S3 handles the copy so the client does not need to fetch the 
data and upload it again. You can also change the storage 
class and metadata of the object when copying.

It uses copy_object method internal, so the copy functionality allows you to copy objects within or between your S3 buckets, and optionally to replace the metadata associated with the object in the process.

Standard method (download/upload)

Copy method

Code sample:

require 'aws-sdk'

AWS.config(
  :access_key_id     => '***',
  :secret_access_key => '***',
  :max_retries       => 10
)

file     = 'test_file.rb'
bucket_0 = {:name => 'bucket_from', :endpoint => 's3-eu-west-1.amazonaws.com'}
bucket_1 = {:name => 'bucket_to',   :endpoint => 's3.amazonaws.com'}

s3_interface_from = AWS::S3.new(:s3_endpoint => bucket_0[:endpoint])
bucket_from       = s3_interface_from.buckets[bucket_0[:name]]
bucket_from.objects[file].write(open(file))

s3_interface_to   = AWS::S3.new(:s3_endpoint => bucket_1[:endpoint])
bucket_to         = s3_interface_to.buckets[bucket_1[:name]]
bucket_to.objects[file].copy_from(file, {:bucket => bucket_from})