Use the AWS SDK Ruby gem to create new copies of objects without an invalid Content-Encoding metadata field

reset_encoding.rb

#!/usr/bin/env ruby
require 'aws-sdk'

INVALID_ENCODINGS = %w(ANSI_X3.4-1968 UTF-8)

bucket = Aws::S3::Bucket.new(
  region: 'us-east-1',
  name: 'www.mysite.com'
)

fail unless bucket.exists?

bucket.objects.each do |objectsummary|
  obj = objectsummary.object

  next unless INVALID_ENCODINGS.include?(obj.content_encoding)

  obj_source = "#{obj.bucket_name}/#{obj.key}"

  printf "%-60s %-8s %-24s %s\n",
         obj.key, obj.content_encoding, obj.content_type, obj_source

  objectsummary.copy_from(
    copy_source: obj_source,
    content_encoding: nil,
    content_type: obj.content_type,
    metadata: obj.metadata,
    metadata_directive: 'REPLACE'
  )
end