Merge pull request #153 from solarwinds/NH-90184

Nh-90184: add feature - add_tracer on function

.rubocop.yml

@@ -49,3 +49,6 @@ Metrics/BlockNesting:
   Exclude:
     - 'lib/solarwinds_apm.rb'
     - 'lib/solarwinds_apm/support.rb'
+Lint/ConstantDefinitionInBlock:
+  Exclude:
+    - 'test/api/custom_instrumentation_test.rb'

lib/solarwinds_apm/api.rb

@@ -11,6 +11,7 @@
 require_relative 'api/tracing'
 require_relative 'api/opentelemetry'
 require_relative 'api/custom_metrics'
+require_relative 'api/custom_instrumentation'
 
 module SolarWindsAPM
   module API
@@ -19,5 +20,6 @@ module API
     extend SolarWindsAPM::API::Tracing
     extend SolarWindsAPM::API::OpenTelemetry
     extend SolarWindsAPM::API::CustomMetrics
+    extend SolarWindsAPM::API::Tracer
   end
 end

lib/solarwinds_apm/api/custom_instrumentation.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+# © 2024 SolarWinds Worldwide, LLC. All rights reserved.
+#
+# 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:http://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.
+
+module SolarWindsAPM
+  module API
+    module Tracer
+      def self.included(base)
+        base.extend(ClassMethods)
+      end
+
+      module ClassMethods
+        def add_tracer(method_name, span_name = nil, options = {})
+          span_name = name.nil? ? "#{to_s.split(':').last&.tr('>', '')}/#{__method__}" : "#{name}/#{__method__}" if span_name.nil?
+
+          original_method = instance_method(method_name)
+
+          define_method(method_name) do |*args, &block|
+            SolarWindsAPM::API.in_span(span_name, **options) do |_span|
+              original_method.bind_call(self, *args, &block)
+            end
+          end
+        end
+      end
+    end
+  end
+end

test/api/custom_instrumentation_test.rb

@@ -0,0 +1,102 @@
+# frozen_string_literal: true
+
+# Copyright (c) 2023 SolarWinds, LLC.
+# All rights reserved.
+
+require 'minitest_helper'
+require './lib/solarwinds_apm/api'
+
+describe 'SolarWinds Custom Instrumentation Test' do
+  let(:sdk) { OpenTelemetry::SDK }
+  let(:exporter) { sdk::Trace::Export::InMemorySpanExporter.new }
+  let(:span_processor) { sdk::Trace::Export::SimpleSpanProcessor.new(exporter) }
+  let(:provider) do
+    OpenTelemetry.tracer_provider = sdk::Trace::TracerProvider.new.tap do |provider|
+      provider.add_span_processor(span_processor)
+    end
+  end
+  let(:tracer) { provider.tracer(__FILE__, sdk::VERSION) }
+  let(:parent_context) { OpenTelemetry::Context.empty }
+  let(:finished_spans) { exporter.finished_spans }
+
+  before do
+    ENV['OTEL_SERVICE_NAME'] = __FILE__
+  end
+
+  after do
+    ENV.delete('OTEL_SERVICE_NAME')
+  end
+
+  it 'test_custom_instrumentation_simple_case' do
+    class MyClass
+      include SolarWindsAPM::API::Tracer
+      def new_method(param1, param2)
+        param1 + param2
+      end
+
+      add_tracer :new_method
+    end
+
+    OpenTelemetry::Context.with_current(parent_context) do
+      tracer.in_span('root') do
+        my_class = MyClass.new
+        my_class.new_method(1, 2)
+      end
+    end
+
+    skip if finished_spans.empty?
+
+    _(finished_spans.size).must_equal(2)
+    _(finished_spans[0].name).must_equal('MyClass/add_tracer')
+    _(finished_spans[0].kind).must_equal(:internal)
+  end
+
+  it 'test_custom_instrumentation_simple_case_with_custom_name_and_options' do
+    class MyClass
+      include SolarWindsAPM::API::Tracer
+      def new_method(param1, param2)
+        param1 + param2
+      end
+
+      add_tracer :new_method, 'custom_name', { attributes: { 'foo' => 'bar' }, kind: :consumer }
+    end
+
+    OpenTelemetry::Context.with_current(parent_context) do
+      tracer.in_span('root') do
+        my_class = MyClass.new
+        my_class.new_method(1, 2)
+      end
+    end
+
+    skip if finished_spans.empty?
+
+    _(finished_spans[0].name).must_equal('custom_name')
+    _(finished_spans[0].attributes['foo']).must_equal('bar')
+    _(finished_spans[0].kind).must_equal(:consumer)
+  end
+
+  it 'test_custom_instrumentation_instance_method' do
+    class MyClass
+      def self.new_method(param1, param2)
+        param1 + param2
+      end
+
+      class << self
+        include SolarWindsAPM::API::Tracer
+        add_tracer :new_method, 'custom_name', { attributes: { 'foo' => 'bar' }, kind: :unknown }
+      end
+    end
+
+    OpenTelemetry::Context.with_current(parent_context) do
+      tracer.in_span('root') do
+        MyClass.new_method(1, 2)
+      end
+    end
+
+    skip if finished_spans.empty?
+
+    _(finished_spans[0].name).must_equal('custom_name')
+    _(finished_spans[0].attributes['foo']).must_equal('bar')
+    _(finished_spans[0].kind).must_equal(:unknown)
+  end
+end