feat: rewrap certain GRPC errors that swallow the underlying auth errors

gapic-common/lib/gapic/call_options/retry_policy.rb

@@ -132,7 +132,10 @@ def hash
       private
 
       def retry? error
-        error.is_a?(::GRPC::BadStatus) && retry_codes.include?(error.code)
+        (error.is_a?(::GRPC::BadStatus) ||
+         error.is_a?(::Gapic::GRPC::AuthorizationError) ||
+         error.is_a?(::Gapic::GRPC::DeadlineExceededError)) &&
+          retry_codes.include?(error.code)
       end
 
       def delay!

gapic-common/lib/gapic/grpc.rb

@@ -13,5 +13,6 @@
 # limitations under the License.
 
 require "grpc"
+require "gapic/grpc/errors"
 require "gapic/grpc/service_stub"
 require "gapic/grpc/status_details"

gapic-common/lib/gapic/grpc/errors.rb

@@ -0,0 +1,60 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require "googleauth"
+require "gapic/common/error"
+
+module Gapic
+  module GRPC
+    ##
+    # An error class to represent the Authorization Error.
+    # The GRPC layer wraps auth plugin errors in ::GRPC::Unavailable.
+    # This class rewraps those GRPC layer errors, presenting a correct status code.
+    #
+    class AuthorizationError < ::GRPC::Unauthenticated
+    end
+
+    ##
+    # An error class that represents Deadline Exceeded error with an optional
+    # retry root cause.
+    #
+    # The GRPC layer throws ::GRPC::DeadlineExceeded without any context.
+    # If the deadline was exceeded while retrying another exception (e.g.
+    # ::GRPC::Unavailable), that exception could be useful for understanding
+    # the readon for the timeout.
+    #
+    # This exception rewraps ::GRPC::DeadlineExceeded, adding an exception
+    # that was being retried until the deadline was exceeded (if any) as a
+    # `root_cause` attribute.
+    #
+    # @!attribute [r] root_cause
+    #   @return [Object, nil] The exception that was being retried
+    #     when the DeadlineExceeded error occured.
+    #
+    class DeadlineExceededError < ::GRPC::DeadlineExceeded
+      attr_reader :root_cause
+
+      ##
+      # @param message [String] The error message.
+      #
+      # @param root_cause [Object, nil] The exception that was being retried
+      #   when the DeadlineExceeded error occured.
+      #
+      def initialize message, root_cause: nil
+        super message
+        @root_cause = root_cause
+      end
+    end
+  end
+end

gapic-common/lib/gapic/grpc/service_stub/rpc_call.rb

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 require "gapic/call_options"
+require "grpc/errors"
 
 module Gapic
   class ServiceStub
@@ -116,13 +117,23 @@ def call request, options: nil
         deadline = calculate_deadline options
         metadata = options.metadata
 
+        retried_exception = nil
         begin
           operation = stub_method.call request, deadline: deadline, metadata: metadata, return_op: true
           response = operation.execute
           yield response, operation if block_given?
           response
+        rescue ::GRPC::DeadlineExceeded => e
+          raise Gapic::GRPC::DeadlineExceededError.new e.message, root_cause: retried_exception
         rescue StandardError => e
-          retry if check_retry?(deadline) && options.retry_policy.call(e)
+          if e.is_a?(::GRPC::Unavailable) && /Signet::AuthorizationError/ =~ e.message
+            e = Gapic::GRPC::AuthorizationError.new e.message.gsub(%r{^\d+:}, "")
+          end
+
+          if check_retry?(deadline) && options.retry_policy.call(e)
+            retried_exception = e
+            retry
+          end
 
           raise e
         end