class Aws::Plugins::S3BucketDns

def valid_subdomain?(bucket_name)
  bucket_name.size < 64 &&
  bucket_name =~ /^[a-z0-9][a-z0-9.-]+[a-z0-9]$/ &&
  bucket_name !~ /(\d+\.){3}\d+/ &&
  bucket_name !~ /[.-]{2}/
end