def construct_arn(new_resource)
      @arn ||= begin
        region = new_resource.driver.aws_config[:region]
        name = new_resource.name
        rds_type = new_resource.rds_tagging_type
        # Taken from example on https://forums.aws.amazon.com/thread.jspa?threadID=108012
        account_id = begin
          u = new_resource.driver.iam.get_user
          # We've got an AWS account root credential or an IAM admin with access rights
          u[:user][:arn].match("^arn:aws:iam::([0-9]{12}):.*$")[1]
        rescue ::Aws::IAM::Errors::AccessDenied => e
          # We've got an AWS IAM Credential
          e.to_s.match("^User: arn:aws:iam::([0-9]{12}):.*$")[1]
        end
        # arn:aws:rds:<region>:<account number>:<resourcetype>:<name>
        "arn:aws:rds:#{region}:#{account_id}:#{rds_type}:#{name}"
      end
    end
def construct_arn(new_resource)
      @arn ||= begin
        region = new_resource.driver.aws_config[:region]
        name = new_resource.name
        rds_type = new_resource.rds_tagging_type
        # Taken from example on https://forums.aws.amazon.com/thread.jspa?threadID=108012
        account_id = begin
          u = new_resource.driver.iam.get_user
          # We've got an AWS account root credential or an IAM admin with access rights
          u[:user][:arn].match("^arn:aws:iam::([0-9]{12}):.*$")[1]
        rescue ::Aws::IAM::Errors::AccessDenied => e
          # We've got an AWS IAM Credential
          e.to_s.match("^User: arn:aws:iam::([0-9]{12}):.*$")[1]
        end
        # arn:aws:rds:<region>:<account number>:<resourcetype>:<name>
        "arn:aws:rds:#{region}:#{account_id}:#{rds_type}:#{name}"
      end
    end
http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Tagging.html#USER_Tagging.ARN