Merge branch 'feat/DEX-2616/composition-metrics' into 'master'

[DEX-2616] Add composition metrics

Closes DEX-2616

See merge request nstmrt/rubygems/sbmt-strangler!25

.gitlab-ci.yml

@@ -10,6 +10,8 @@ tests:
     matrix:
       - RUBY_VERSION: ['3.1', '3.2', '3.3']
   before_script:
+    - gem sources --remove https://rubygems.org/
+    - gem sources --add https://nexus.sbmt.io/repository/rubygems/
     - gem install bundler -v 2.5.7
     - bin/setup
   script:

Gemfile

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
-source "https://rubygems.org"
+source "https://nexus.sbmt.io/repository/rubygems/"
 
 gemspec

config/initializers/yabeda.rb

@@ -4,7 +4,9 @@ module Sbmt
   module Strangler
     module Metrics
       module Yabeda
-        HTTP_BUCKETS = [0.01, 0.02, 0.04, 0.1, 0.2, 0.5, 0.8, 1, 1.5, 2, 5, 15, 30, 60].freeze
+        DEFAULT_BUCKETS = [0.01, 0.02, 0.04, 0.1, 0.2, 0.5, 0.8, 1, 1.5, 2, 5, 15, 30, 60].freeze
+        HTTP_BUCKETS = DEFAULT_BUCKETS
+        COMPOSITION_BUCKETS = DEFAULT_BUCKETS
 
         ::Yabeda.configure do
           group :sbmt_strangler do
@@ -38,3 +40,27 @@ module Yabeda
     end
   end
 end
+
+# Declaring composition step duration metric in an `after_initialize` block
+# allows user to customize buckets in his app-level configuration file:
+#
+#     # config/initializers/strangler.rb
+#     Sbmt::Strangler.configure do |strangler|
+#       strangler.composition_step_duration_metric_buckets = [0.1, 0.2, 0.3]
+#     end
+#
+Rails.application.config.after_initialize do
+  ::Yabeda.configure do
+    group :sbmt_strangler do
+      composition_buckets =
+        ::Sbmt::Strangler.configuration.composition_step_duration_metric_buckets ||
+        ::Sbmt::Strangler::Metrics::Yabeda::COMPOSITION_BUCKETS
+
+      histogram :composition_step_duration,
+        tags: %i[step part type level parent controller action],
+        unit: :seconds,
+        buckets: composition_buckets,
+        comment: "Composition step duration"
+    end
+  end
+end

lib/sbmt/strangler/action.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_relative "action/composition"
+require_relative "action/composition/step"
 
 module Sbmt
   module Strangler
@@ -36,9 +36,11 @@ def http_client
       end
 
       def composition(&)
-        return @composition unless block_given?
-
-        @composition = Sbmt::Strangler::Action::Composition.new(&)
+        if block_given?
+          @composition ||= Composition::Step.new(name: :root)
+          yield(@composition)
+        end
+        @composition
       end
 
       def composition?

lib/sbmt/strangler/action/composition/errors/configuration_error.rb

@@ -3,7 +3,7 @@
 module Sbmt
   module Strangler
     class Action
-      class Composition
+      module Composition
         module Errors
           class ConfigurationError < StandardError; end
         end

lib/sbmt/strangler/action/composition/errors/max_composition_level_error.rb → lib/sbmt/strangler/action/composition/errors/max_level_error.rb

@@ -3,9 +3,9 @@
 module Sbmt
   module Strangler
     class Action
-      class Composition
+      module Composition
         module Errors
-          class MaxCompositionLevelError < StandardError; end
+          class MaxLevelError < StandardError; end
         end
       end
     end

lib/sbmt/strangler/action/composition/metrics.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+module Sbmt
+  module Strangler
+    class Action
+      module Composition
+        module Metrics
+          private
+
+          def with_metrics(rails_controller:, part: nil)
+            result = nil
+            with_yabeda_duration_measurement(rails_controller: rails_controller, part: part) do
+              with_open_telemetry_tracing(part: part) do
+                result = yield
+              end
+            end
+            result
+          end
+
+          def with_yabeda_duration_measurement(rails_controller:, part: nil)
+            result = nil
+            yabeda_tags = {
+              step: name.to_s,
+              part: part&.to_s,
+              type: type.to_s,
+              level: level.to_s,
+              parent: parent&.name&.to_s,
+              controller: rails_controller.controller_path,
+              action: rails_controller.action_name
+            }
+            Yabeda.sbmt_strangler.composition_step_duration.measure(yabeda_tags) do
+              result = yield
+            end
+            result
+          end
+
+          def with_open_telemetry_tracing(part: nil)
+            return yield unless Object.const_defined?(:OpenTelemetry)
+
+            span_name = "Composition step: #{name}"
+            span_name += " (#{part})" unless part.nil?
+
+            span_attrs = {type: type.to_s, level: level}
+            span_attrs[:parent] = parent.name.to_s unless parent.nil?
+
+            result = nil
+            ::OpenTelemetry.tracer_provider.tracer("Sbmt::Strangler")
+              .in_span(span_name, attributes: span_attrs, kind: :internal) do |_span|
+                result = yield
+              end
+            result
+          end
+        end
+      end
+    end
+  end
+end