Download blobs from s3 so can serve from active_storage.service = :local

s3.rake

require 'aws-sdk-s3'

namespace :s3 do
  desc "Download blobs from s3 so can serve from active_storage.service = :local"
  task :download => :environment do

    s3 = Aws::S3::Client.new
    bucket = '<bucket_name>' # TODO: your bucket name here
    objects = s3.list_objects(bucket: bucket).contents

    # skip the variants; they are made on demand for :local
    objects = objects.reject {|o| o.key.starts_with?("variants")}
    
    puts "Downloading #{objects.size} from s3 to local disk"
    objects.each_with_index do |object, index|
        # store blobs using same folder scheme as :local
        storage_path = Rails.root.join("storage/#{object.key[0..1]}/#{object.key[2..3]}")
        storage_path.mkpath

        s3.get_object(
            response_target: storage_path.join(object.key),
            bucket: bucket,
            key: object.key
        )
        puts "#{index + 1} / #{objects.size}"
    end
  end
end