Grants public read to an S3 bucket

grant-public-read-to-bucket.rb

#!/usr/bin/ruby

require 'rubygems'
require 'aws/s3'

include AWS::S3

AWS::S3::Base.establish_connection!(
    :access_key_id     => 'abc',
    :secret_access_key => '123'
)

bucket = Bucket.find('some-bucket')

# cached here so we don't create it 10**6 times
public_read_grant = ACL::Grant.grant(:public_read)

objects = bucket.objects(:marker => ARGV.shift || '')
end_marker = ARGV.shift || nil
until objects.size == 0
  objects.each do |object|
    begin
      unless object.acl.grants.include?(public_read_grant)
        object.acl.grants << public_read_grant
        object.acl(object.acl)
        puts "Made public: #{object.key}"
      else
        puts "Already public: #{object.key}"
      end
    # for some reason, despite S3 telling us there was
    # a key here a second ago, they have a tendency to
    # disapppear every once in a while
    rescue AWS::S3::NoSuchKey
      puts "AWS::S3::NoSuchKey: #{object.key}"
    rescue Errno::ECONNRESET
      puts "ECONNRESET while modifying ACL. Retrying..."
      retry
    end
  end
  # reload bucket objects starting from last current object
  begin
    objects = bucket.objects(:marker => bucket.objects.last.key)
  rescue Errno::ECONNRESET
    puts "ECONNRESET while getting more objects. Retrying..."
    retry
  end
end