add settings for telemetry metrics

lib/datadog/core/configuration/settings.rb

@@ -663,6 +663,16 @@ def initialize(*_)
             o.type :bool
           end
 
+          # Enable metrics collection for telemetry. Metrics collection only works when telemetry is enabled and
+          # metrics are enabled.
+          # @default `DD_TELEMETRY_METRICS_ENABLED` environment variable, otherwise `true`.
+          # @return [Boolean]
+          option :metrics_enabled do |o|
+            o.type :bool
+            o.env Core::Telemetry::Ext::ENV_METRICS_ENABLED
+            o.default true
+          end
+
           # The interval in seconds when telemetry must be sent.
           #
           # This method is used internally, for testing purposes only.
@@ -676,6 +686,19 @@ def initialize(*_)
             o.default 60.0
           end
 
+          # The interval in seconds when telemetry metrics are aggregated.
+          # Should be a denominator of `heartbeat_interval_seconds`.
+          #
+          # This method is used internally, for testing purposes only.
+          # @default `DD_TELEMETRY_METRICS_AGGREGATION_INTERVAL` environment variable, otherwise `10`.
+          # @return [Float]
+          # @!visibility private
+          option :metrics_aggregation_interval_seconds do |o|
+            o.type :float
+            o.env Core::Telemetry::Ext::ENV_METRICS_AGGREGATION_INTERVAL
+            o.default 10.0
+          end
+
           # The install id of the application.
           #
           # This method is used internally, by library injection.

lib/datadog/core/telemetry/ext.rb

@@ -5,7 +5,9 @@ module Core
     module Telemetry
       module Ext
         ENV_ENABLED = 'DD_INSTRUMENTATION_TELEMETRY_ENABLED'
+        ENV_METRICS_ENABLED = 'DD_TELEMETRY_METRICS_ENABLED'
         ENV_HEARTBEAT_INTERVAL = 'DD_TELEMETRY_HEARTBEAT_INTERVAL'
+        ENV_METRICS_AGGREGATION_INTERVAL = 'DD_TELEMETRY_METRICS_AGGREGATION_INTERVAL'
         ENV_DEPENDENCY_COLLECTION = 'DD_TELEMETRY_DEPENDENCY_COLLECTION_ENABLED'
         ENV_INSTALL_ID = 'DD_INSTRUMENTATION_INSTALL_ID'
         ENV_INSTALL_TYPE = 'DD_INSTRUMENTATION_INSTALL_TYPE'

sig/datadog/core/telemetry/ext.rbs

@@ -4,7 +4,9 @@ module Datadog
       module Ext
         ENV_DEPENDENCY_COLLECTION: ::String
         ENV_ENABLED: ::String
+        ENV_METRICS_ENABLED: ::String
         ENV_HEARTBEAT_INTERVAL: ::String
+        ENV_METRICS_AGGREGATION_INTERVAL: ::String
         ENV_INSTALL_ID: ::String
         ENV_INSTALL_TIME: ::String
         ENV_INSTALL_TYPE: ::String

spec/datadog/core/configuration/settings_spec.rb

@@ -1476,6 +1476,39 @@
       end
     end
 
+    describe '#metrics_enabled' do
+      subject(:metrics_enabled) { settings.telemetry.metrics_enabled }
+      let(:env_var_name) { 'DD_TELEMETRY_METRICS_ENABLED' }
+
+      context 'when DD_TELEMETRY_METRICS_ENABLED' do
+        context 'is not defined' do
+          let(:env_var_value) { nil }
+
+          it { is_expected.to be true }
+        end
+
+        [true, false].each do |value|
+          context "is defined as #{value}" do
+            let(:env_var_value) { value.to_s }
+
+            it { is_expected.to be value }
+          end
+        end
+      end
+    end
+
+    describe '#metrics_enabled=' do
+      let(:env_var_name) { 'DD_TELEMETRY_METRICS_ENABLED' }
+      let(:env_var_value) { 'true' }
+
+      it 'updates the #metrics_enabled setting' do
+        expect { settings.telemetry.metrics_enabled = false }
+          .to change { settings.telemetry.metrics_enabled }
+          .from(true)
+          .to(false)
+      end
+    end
+
     describe '#heartbeat_interval' do
       subject(:heartbeat_interval_seconds) { settings.telemetry.heartbeat_interval_seconds }
       let(:env_var_name) { 'DD_TELEMETRY_HEARTBEAT_INTERVAL' }
@@ -1505,6 +1538,35 @@
       end
     end
 
+    describe '#metrics_aggregation_interval_seconds' do
+      subject(:metrics_aggregation_interval_seconds) { settings.telemetry.metrics_aggregation_interval_seconds }
+      let(:env_var_name) { 'DD_TELEMETRY_METRICS_AGGREGATION_INTERVAL' }
+
+      context 'when DD_TELEMETRY_METRICS_AGGREGATION_INTERVAL' do
+        context 'is not defined' do
+          let(:env_var_value) { nil }
+
+          it { is_expected.to eq 10.0 }
+        end
+
+        context 'is defined' do
+          let(:env_var_value) { '1.1' }
+
+          it { is_expected.to eq 1.1 }
+        end
+      end
+    end
+
+    describe '#metrics_aggregation_interval_seconds=' do
+      let(:env_var_name) { 'DD_TELEMETRY_METRICS_AGGREGATION_INTERVAL' }
+      let(:env_var_value) { '1.1' }
+
+      it 'updates the #metrics_aggregation_interval_seconds setting' do
+        expect { settings.telemetry.metrics_aggregation_interval_seconds = 2.2 }
+          .to change { settings.telemetry.metrics_aggregation_interval_seconds }.from(1.1).to(2.2)
+      end
+    end
+
     describe '#install_id' do
       subject(:install_id) { settings.telemetry.install_id }
       let(:env_var_name) { 'DD_INSTRUMENTATION_INSTALL_ID' }