instance method issuer

# File activestorage/lib/active_storage/service/gcs_service.rb, line 197
      def issuer
        @issuer ||= if @config[:gsa_email]
          @config[:gsa_email]
        else
          uri = URI.parse("http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/email")
          http = Net::HTTP.new(uri.host, uri.port)
          request = Net::HTTP::Get.new(uri.request_uri)
          request["Metadata-Flavor"] = "Google"

          begin
            response = http.request(request)
          rescue SocketError
            raise MetadataServerNotFoundError
          end

          if response.is_a?(Net::HTTPSuccess)
            response.body
          else
            raise MetadataServerError
          end
        end
      end