introduce sequence for configuration changes reported by telemetry

lib/datadog/core/telemetry/event.rb

@@ -3,7 +3,16 @@
 module Datadog
   module Core
     module Telemetry
+      # Collection of telemetry events
       class Event
+        extend Core::Utils::Forking
+
+        # returns sequence that increments every time the configuration changes
+        def self.configuration_sequence
+          after_fork! { @sequence = Datadog::Core::Utils::Sequence.new(1) }
+          @sequence ||= Datadog::Core::Utils::Sequence.new(1)
+        end
+
         # Base class for all Telemetry V2 events.
         class Base
           # The type of the event.
@@ -12,8 +21,7 @@ class Base
           def type; end
 
           # The JSON payload for the event.
-          # @param seq_id [Integer] The sequence ID for the event.
-          def payload(seq_id)
+          def payload
             {}
           end
         end
@@ -24,8 +32,7 @@ def type
             'app-started'
           end
 
-          def payload(seq_id)
-            @seq_id = seq_id
+          def payload
             {
               products: products,
               configuration: configuration,
@@ -80,16 +87,19 @@ def products
           ].freeze
 
           # rubocop:disable Metrics/AbcSize
+          # rubocop:disable Metrics/MethodLength
           def configuration
             config = Datadog.configuration
+            seq_id = Event.configuration_sequence.next
 
             list = [
-              conf_value('DD_AGENT_HOST', config.agent.host),
-              conf_value('DD_AGENT_TRANSPORT', agent_transport(config)),
-              conf_value('DD_TRACE_SAMPLE_RATE', to_value(config.tracing.sampling.default_rate)),
+              conf_value('DD_AGENT_HOST', config.agent.host, seq_id),
+              conf_value('DD_AGENT_TRANSPORT', agent_transport(config), seq_id),
+              conf_value('DD_TRACE_SAMPLE_RATE', to_value(config.tracing.sampling.default_rate), seq_id),
               conf_value(
                 'DD_TRACE_REMOVE_INTEGRATION_SERVICE_NAMES_ENABLED',
-                config.tracing.contrib.global_default_service_name.enabled
+                config.tracing.contrib.global_default_service_name.enabled,
+                seq_id
               ),
             ]
 
@@ -98,32 +108,45 @@ def configuration
               peer_service_mapping = config.tracing.contrib.peer_service_mapping
               peer_service_mapping_str = peer_service_mapping.map { |key, value| "#{key}:#{value}" }.join(',')
             end
-            list << conf_value('DD_TRACE_PEER_SERVICE_MAPPING', peer_service_mapping_str)
+            list << conf_value('DD_TRACE_PEER_SERVICE_MAPPING', peer_service_mapping_str, seq_id)
 
             # Whitelist of configuration options to send in additional payload object
             TARGET_OPTIONS.each do |option|
               split_option = option.split('.')
-              list << conf_value(option, to_value(config.dig(*split_option)))
+              list << conf_value(option, to_value(config.dig(*split_option)), seq_id)
             end
 
             # Add some more custom additional payload values here
             list.push(
-              conf_value('tracing.auto_instrument.enabled', !defined?(Datadog::AutoInstrument::LOADED).nil?),
-              conf_value('tracing.writer_options.buffer_size', to_value(config.tracing.writer_options[:buffer_size])),
-              conf_value('tracing.writer_options.flush_interval', to_value(config.tracing.writer_options[:flush_interval])),
-              conf_value('tracing.opentelemetry.enabled', !defined?(Datadog::OpenTelemetry::LOADED).nil?),
+              conf_value('tracing.auto_instrument.enabled', !defined?(Datadog::AutoInstrument::LOADED).nil?, seq_id),
+              conf_value(
+                'tracing.writer_options.buffer_size',
+                to_value(config.tracing.writer_options[:buffer_size]),
+                seq_id
+              ),
+              conf_value(
+                'tracing.writer_options.flush_interval',
+                to_value(config.tracing.writer_options[:flush_interval]),
+                seq_id
+              ),
+              conf_value(
+                'tracing.opentelemetry.enabled',
+                !defined?(Datadog::OpenTelemetry::LOADED).nil?,
+                seq_id
+              ),
             )
-            list << conf_value('logger.instance', config.logger.instance.class.to_s) if config.logger.instance
+            list << conf_value('logger.instance', config.logger.instance.class.to_s, seq_id) if config.logger.instance
             if config.respond_to?('appsec')
-              list << conf_value('appsec.enabled', config.dig('appsec', 'enabled'))
-              list << conf_value('appsec.sca_enabled', config.dig('appsec', 'sca_enabled'))
+              list << conf_value('appsec.enabled', config.dig('appsec', 'enabled'), seq_id)
+              list << conf_value('appsec.sca_enabled', config.dig('appsec', 'sca_enabled'), seq_id)
             end
-            list << conf_value('ci.enabled', config.dig('ci', 'enabled')) if config.respond_to?('ci')
+            list << conf_value('ci.enabled', config.dig('ci', 'enabled'), seq_id) if config.respond_to?('ci')
 
             list.reject! { |entry| entry[:value].nil? }
             list
           end
           # rubocop:enable Metrics/AbcSize
+          # rubocop:enable Metrics/MethodLength
 
           def agent_transport(config)
             adapter = Core::Configuration::AgentSettingsResolver.call(config).adapter
@@ -134,12 +157,12 @@ def agent_transport(config)
             end
           end
 
-          def conf_value(name, value, origin = 'code')
+          def conf_value(name, value, seq_id, origin = 'code')
             {
               name: name,
               value: value,
               origin: origin,
-              seq_id: @seq_id,
+              seq_id: seq_id,
             }
           end
 
@@ -169,7 +192,7 @@ def type
             'app-dependencies-loaded'
           end
 
-          def payload(seq_id)
+          def payload
             { dependencies: dependencies }
           end
 
@@ -192,7 +215,7 @@ def type
             'app-integrations-change'
           end
 
-          def payload(seq_id)
+          def payload
             { integrations: integrations }
           end
 
@@ -245,18 +268,20 @@ def initialize(changes, origin)
             @origin = origin
           end
 
-          def payload(seq_id)
-            { configuration: configuration(seq_id) }
+          def payload
+            { configuration: configuration }
           end
 
-          def configuration(seq_id)
+          def configuration
             config = Datadog.configuration
+            seq_id = Event.configuration_sequence.next
 
             res = @changes.map do |name, value|
               {
                 name: name,
                 value: value,
                 origin: @origin,
+                seq_id: seq_id,
               }
             end
 
@@ -299,7 +324,7 @@ def initialize(namespace, metric_series)
             @metric_series = metric_series
           end
 
-          def payload(_)
+          def payload
             {
               namespace: @namespace,
               series: @metric_series.map(&:to_h)
@@ -326,11 +351,11 @@ def initialize(events)
             @events = events
           end
 
-          def payload(seq_id)
+          def payload
             @events.map do |event|
               {
                 request_type: event.type,
-                payload: event.payload(seq_id),
+                payload: event.payload,
               }
             end
           end

lib/datadog/core/telemetry/request.rb

@@ -17,7 +17,7 @@ def build_payload(event, seq_id)
               application: application,
               debug: false,
               host: host,
-              payload: event.payload(seq_id),
+              payload: event.payload,
               request_type: event.type,
               runtime_id: Core::Environment::Identity.id,
               seq_id: seq_id,

sig/datadog/core/telemetry/emitter.rbs

@@ -2,7 +2,7 @@ module Datadog
   module Core
     module Telemetry
       class Emitter
-        @sequence: Datadog::Core::Utils::Sequence
+        self.@sequence: Datadog::Core::Utils::Sequence
 
         attr_reader http_transport: untyped
 

sig/datadog/core/telemetry/event.rbs

@@ -2,16 +2,20 @@ module Datadog
   module Core
     module Telemetry
       class Event
+        extend Core::Utils::Forking
+
+        self.@sequence: Datadog::Core::Utils::Sequence
+
+        def self.configuration_sequence: () -> Datadog::Core::Utils::Sequence
+
         class Base
-          def payload: (int seq_id) -> (Hash[Symbol, untyped] | Array[Hash[Symbol, untyped]])
+          def payload: () -> (Hash[Symbol, untyped] | Array[Hash[Symbol, untyped]])
           def type: -> String?
         end
 
         class AppStarted < Base
           TARGET_OPTIONS: Array[String]
 
-          @seq_id: int
-
           private
 
           def products: -> Hash[Symbol, untyped]
@@ -20,7 +24,7 @@ module Datadog
 
           def agent_transport: (untyped config) -> String
 
-          def conf_value: (String name, Object value, ?String origin) -> Hash[Symbol, untyped]
+          def conf_value: (String name, Object value, Integer seq_id, ?String origin) -> Hash[Symbol, untyped]
 
           def to_value: (Object value) -> Object
 
@@ -47,7 +51,7 @@ module Datadog
 
           def initialize: (Enumerable[[String, Numeric | bool | String]] changes, String origin) -> void
 
-          def configuration: (int seq_id) -> Array[Hash[Symbol, untyped]]
+          def configuration: () -> Array[Hash[Symbol, untyped]]
         end
 
         class AppHeartbeat < Base

spec/datadog/core/telemetry/event_spec.rb

@@ -5,7 +5,7 @@
 
 RSpec.describe Datadog::Core::Telemetry::Event do
   let(:id) { double('seq_id') }
-  subject(:payload) { event.payload(id) }
+  subject(:payload) { event.payload }
 
   context 'AppStarted' do
     let(:event) { described_class::AppStarted.new }
@@ -14,6 +14,8 @@
     end
 
     before do
+      allow_any_instance_of(Datadog::Core::Utils::Sequence).to receive(:next).and_return(id)
+
       Datadog.configure do |c|
         c.agent.host = '1.2.3.4'
         c.tracing.sampling.default_rate = 0.5
@@ -164,12 +166,17 @@ def contain_configuration(*array)
     let(:name) { 'key' }
     let(:value) { 'value' }
 
+    before do
+      allow_any_instance_of(Datadog::Core::Utils::Sequence).to receive(:next).and_return(id)
+    end
+
     it 'has a list of client configurations' do
       is_expected.to eq(
         configuration: [{
           name: name,
           value: value,
           origin: origin,
+          seq_id: id
         }]
       )
     end
@@ -185,7 +192,7 @@ def contain_configuration(*array)
         is_expected.to eq(
           configuration:
           [
-            { name: name, value: value, origin: origin },
+            { name: name, value: value, origin: origin, seq_id: id },
             { name: 'appsec.sca_enabled', value: false, origin: 'code', seq_id: id }
           ]
         )