feat: parts of the gRPC istrumentation (#1330)

* feat(grpc): write the client tracing instrumentation in the interceptor manner

* feat(grpc): migrate from rspec to minitest

* feat(grpc): introduce Appraisals

* fix(grpc): remove active_support dependency

* Update grpc.rb

* Update README.md

* ci: add (probably) missing grpc gem in the ci-instrumentation

* cI: grpc is not included in the all gem yet

* ci: skip grpc from the CI for now

* a better approach towards client testing

* add an unversioned Appraisal

Co-authored-by: Kayla Reopelle <[email protected]>

* Update instrumentation/grpc/README.md

Co-authored-by: Kayla Reopelle <[email protected]>

* Update instrumentation/grpc/lib/opentelemetry/instrumentation/grpc/patches/client_stub.rb

Co-authored-by: Kayla Reopelle <[email protected]>

* Update instrumentation/grpc/test/test_helper.rb

Co-authored-by: Kayla Reopelle <[email protected]>

* add opentelemetry-test-helpers and rake as development dependencies

---------

Co-authored-by: Kayla Reopelle <[email protected]>

Author: michal-kazmierczak

instrumentation/all/Gemfile

@@ -15,9 +15,10 @@ group :test do
      .sort
      .each { |dir| gem "opentelemetry-helpers-#{dir}", path: "../../helpers/#{dir}" }
 
+  excluded_instrumentations = %w[. .. all grpc]
   Dir.entries('../')
      .select { |entry| File.directory?(File.join('../', entry)) }
-     .reject { |entry| %w[. .. all].include?(entry) } # rubocop:disable Performance/CollectionLiteralInLoop
+     .reject { |entry| excluded_instrumentations.include?(entry) }
      .sort
      .each { |dir| gem "opentelemetry-instrumentation-#{dir}", path: "../#{dir}" }
 end

instrumentation/grpc/.rspec

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+appraise 'grpc-1.68' do
+  gem 'grpc', '~> 1.68.0'
+end
+
+appraise 'grpc-latest' do
+  gem 'grpc'
+end

instrumentation/grpc/Appraisals

@@ -9,9 +9,7 @@ source "https://rubygems.org"
 # Specify your gem's dependencies in opentelemetry-instrumentation-grpc.gemspec
 gemspec
 
-gem "rake", "~> 13.0"
-gem "rspec", "~> 3.0"
-gem "standard", "~> 1.3"
-gem "opentelemetry-sdk", "~> 1.0"
-gem "opentelemetry-test-helpers"
-gem "grpc"
+group :test do
+  gem 'opentelemetry-instrumentation-base', path: '../base'
+  gem 'pry'
+end

instrumentation/grpc/Gemfile

@@ -46,18 +46,13 @@ instrumentation.
   end
 ```
 
-You *also* need to make sure your stubs are using the interceptor, e.g.
-
-```ruby
-  otel = OpenTelemetry::Instrumentation::Grpc.client_interceptor
-  SomeService::Stub.new(host, credentials, *args, **kwargs, interceptors: [otel])
-```
-
 ## Development
 
-After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
+Integration tests rely on a real gRPC server that is started by relevant tests. The proto definition is located in `test/support/proto/ping.proto`. Making changes to the proto definition requires re-creating gRPC-generated code. To do this, run the following command:
 
-To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and the created tag, and push the `.gem` file to [rubygems.org](https://rubygems.org).
+```sh
+bundle exec grpc_tools_ruby_protoc --ruby_out=. --grpc_out=. test/support/proto/ping.proto
+```
 
 ## Contributing
 

instrumentation/grpc/README.md

@@ -4,11 +4,25 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-require "bundler/gem_tasks"
-require "rspec/core/rake_task"
+require 'bundler/gem_tasks'
+require 'rake/testtask'
+require 'yard'
+require 'rubocop/rake_task'
 
-RSpec::Core::RakeTask.new(:spec)
+RuboCop::RakeTask.new
 
-require "standard/rake"
+Rake::TestTask.new :test do |t|
+  t.libs << 'test'
+  t.libs << 'lib'
+  t.test_files = FileList['test/**/*_test.rb']
+end
 
-task default: %i[spec standard]
+YARD::Rake::YardocTask.new do |t|
+  t.stats_options = ['--list-undoc']
+end
+
+if RUBY_ENGINE == 'truffleruby'
+  task default: %i[test]
+else
+  task default: %i[test rubocop yard]
+end

instrumentation/grpc/Rakefile

@@ -6,23 +6,16 @@
 
 require "opentelemetry"
 require "opentelemetry-instrumentation-base"
-require "active_support/inflector"
 
 module OpenTelemetry
   module Instrumentation
     # Contains the OpenTelemetry instrumentation for the gRPC gem
     module Grpc
       class Error < StandardError; end
-
-      module_function
-
-      def client_interceptor
-        Interceptors::Client.new
-      end
     end
   end
 end
 
 require_relative "grpc/instrumentation"
-require_relative "grpc/interceptors/client"
 require_relative "grpc/version"
+require_relative 'grpc/interceptors/client_tracer'

instrumentation/grpc/lib/opentelemetry/instrumentation/grpc.rb

@@ -24,11 +24,12 @@ class Instrumentation < OpenTelemetry::Instrumentation::Base
         private
 
         def patch
-          ::GRPC::ClientInterceptor.prepend(Interceptors::Client)
+          ::GRPC::ClientStub.prepend(Patches::ClientStub)
         end
 
         def require_dependencies
-          require_relative "interceptors/client"
+          require_relative 'interceptors/client_tracer'
+          require_relative 'patches/client_stub'
         end
       end
     end

instrumentation/grpc/lib/opentelemetry/instrumentation/grpc/instrumentation.rb

@@ -8,7 +8,8 @@ module OpenTelemetry
   module Instrumentation
     module Grpc
       module Interceptors
-        class Client
+        # ClientTracer is a gRPC client interceptor which instrument gRPC calls with OpenTelemetry tracing
+        class ClientTracer < ::GRPC::ClientInterceptor
           def request_response(request: nil, call: nil, method: nil, metadata: nil, &blk)
             call(type: "request_response", requests: [request], call: call, method: method, metadata: metadata, &blk)
           end

instrumentation/grpc/lib/opentelemetry/instrumentation/grpc/interceptors/client.rb renamed to instrumentation/grpc/lib/opentelemetry/instrumentation/grpc/interceptors/client_tracer.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+module OpenTelemetry
+  module Instrumentation
+    module Grpc
+      module Patches
+        # Module to be prepended to force gRPC to use the client interceptor by
+        # default so the user doesn't have to manually add it when initializing a client.
+        module ClientStub
+          def initialize(host, creds, **args)
+            interceptors = args[:interceptors] || []
+            interceptors.unshift(Interceptors::ClientTracer.new) unless interceptors.any? do |interceptor|
+              interceptor.is_a?(Interceptors::ClientTracer)
+            end
+            args[:interceptors] = interceptors
+
+            super
+          end
+        end
+      end
+    end
+  end
+end