AWSの簡易S3ダウンロードRubyスクリプト

s3_downloader.rb

require 'rubygems'
gem 'aws-sdk'
require 'aws'
require 'optparse'

access_key_id = nil
secret_access_key = nil
endpoint = 's3-ap-northeast-1.amazonaws.com'
bucket = nil
object_key = nil
output_file = nil

opt = OptionParser.new
opt.on('-a', '--access-key-id=VAL') { |v| access_key_id = v }
opt.on('-s', '--secret-access-key=VAL') { |v| secret_access_key = v }
opt.on('-b', '--bucket=VAL') { |v| bucket = v }
opt.on('-k', '--object-key=VAL') { |v| object_key = v }
opt.on('-o', '--output-file=VAL', "Default:object-key basename") { |v| output_file = v }
opt.on('-e', '--endpoint=VAL', "Default:#{endpoint}") { |v| endpoint = v }
opt.parse!(ARGV)

output_file = File.basename(object_key) unless output_file
AWS.config(:access_key_id => access_key_id, :secret_access_key => secret_access_key) if access_key_id && secret_access_key

s3 = AWS::S3.new(:s3_endpoint => endpoint,
                 :proxy_uri   => ENV['HTTPS_PROXY'] || ENV['https_proxy'] || ENV['HTTP_PROXY'] || ENV['http_proxy'])
bucket = s3.buckets[bucket]
object = bucket.objects[object_key]

File.open(output_file, 'w') do |file|
  object.read do |chunk|
    file.write chunk
  end
end