[APMAPI-1594] (DO-NOT-MERGE) Add support for config inversion on datadog-ci-rb

lib/datadog/core/configuration/config_helper.rb

@@ -44,6 +44,18 @@ def key?(name)
         alias_method :include?, :key?
         alias_method :member?, :key?
 
+        # This method will be used by datadog-ci-rb once it will bump its minimum dependancy of dd-trace-rb to 2.27.0.
+        # Currently, datadog-ci-rb is compatible with all version of dd-trace-rb > 2.4.0, and we introduced ConfigHelper in 2.21.0.
+        # For version of dd-trace-rb > 2.21.0 and < 2.27.0, we still monkey-patch DATADOG_ENV and use ConfigHelper
+        # (although checks that envs are registered will be ignored as we were not supporting datadog-ci-rb yet),
+        # but we have to use ConfigHelper#instance_variable_get(:@source_env) to set environment variables, as ConfigHelper#[]= was not defined.
+        # Once datadog-ci-rb will bump its minimum dependancy of dd-trace-rb to the one that implements ConfigHelper#[]= (2.27.0),
+        # we can stop using ConfigHelper#instance_variable_get(:@source_env) and use ConfigHelper#[]= instead.
+        # datadog-ci-rb do not plan to bump its minimum dependancy of dd-trace-rb to 2.27.0 in its next release, so we cannot use ConfigHelper#[]= for now.
+        def []=(name, value)
+          @source_env[name] = value
+        end
+
         # Returns the environment variable value if the environment variable is a supported Datadog configuration (starts with DD_ or OTEL_)
         # or if it is not a Datadog configuration. Otherwise, it returns nil.
         #
@@ -53,9 +65,8 @@ def key?(name)
         # @return [String, nil] The environment variable value
         # @raise [RuntimeError] if the configuration is not supported
         def get_environment_variable(name, default_value = nil, source_env: @source_env)
-          # datadog-ci-rb is using dd-trace-rb config DSL, which uses this method.
-          # Until we've correctly implemented support for datadog-ci-rb, we disable config inversion if ci is enabled.
-          if !defined?(::Datadog::CI) &&
+          # Skip if datadog-ci-rb is loaded but does not support config inversion yet
+          if (!defined?(::Datadog::CI) || defined?(::Datadog::CI::Configuration::SUPPORTED_CONFIGURATION_NAMES)) &&
               (name.start_with?('DD_', 'OTEL_') || @alias_to_canonical[name]) &&
               !@supported_configurations.include?(name)
             if defined?(@raise_on_unknown_env_var) && @raise_on_unknown_env_var # Only enabled for tests!

lib/datadog/core/configuration/deprecations.rb

@@ -8,10 +8,13 @@ module Datadog
   module Core
     module Configuration
       module Deprecations
-        LOG_DEPRECATIONS_ONLY_ONCE = Datadog::Core::Utils::OnlyOnce.new
+        # Hash of OnlyOnce instances, as we may call log_deprecations_from_all_sources from datadog-ci-rb too with different deprecations set
+        LOG_DEPRECATIONS_ONLY_ONCE = {}
 
         def self.log_deprecations_from_all_sources(logger, deprecations: DEPRECATIONS, alias_to_canonical: ALIAS_TO_CANONICAL)
-          LOG_DEPRECATIONS_ONLY_ONCE.run do
+          # This way of initializing the `OnlyOnce` is not thread-safe but that's OK here
+          LOG_DEPRECATIONS_ONLY_ONCE[deprecations] ||= Datadog::Core::Utils::OnlyOnce.new
+          LOG_DEPRECATIONS_ONLY_ONCE[deprecations].run do
             log_deprecated_environment_variables(logger, ENV, 'environment', deprecations, alias_to_canonical)
             customer_config = StableConfig.configuration.dig(:local, :config)
             log_deprecated_environment_variables(logger, customer_config, 'local', deprecations, alias_to_canonical) if customer_config

sig/datadog/core/configuration/config_helper.rbs

@@ -28,6 +28,8 @@ module Datadog
         alias include? key?
         alias member? key?
 
+        def []=: (String name, String value) -> void
+
         def get_environment_variable: (String name, ?String? default_value, ?source_env: env_hash) -> String?
 
         def resolve_env: (String name, ?source_env: env_hash) -> String

sig/datadog/core/configuration/deprecations.rbs

@@ -2,7 +2,7 @@ module Datadog
   module Core
     module Configuration
       module Deprecations
-        LOG_DEPRECATIONS_ONLY_ONCE: Datadog::Core::Utils::OnlyOnce
+        LOG_DEPRECATIONS_ONLY_ONCE: Hash[Set[String], Datadog::Core::Utils::OnlyOnce]
 
         def self.log_deprecations_from_all_sources: (Datadog::Core::Logger logger, ?deprecations: Set[String], ?alias_to_canonical: Hash[String, String]) -> void
 

spec/datadog/core/configuration/config_helper_spec.rb

@@ -174,9 +174,9 @@
       end
     end
 
-    context 'when Datadog::CI is defined' do
+    context 'when Datadog::CI is defined but version is too low' do
       before do
-        stub_const('Datadog::CI', Module.new)
+        stub_const('Datadog::CI::VERSION::STRING', '1.26.0')
       end
 
       subject do

spec/datadog/core/configuration/deprecations_spec.rb

@@ -16,7 +16,7 @@
     end
 
     before do
-      described_class.const_get('LOG_DEPRECATIONS_ONLY_ONCE').send(:reset_ran_once_state_for_tests)
+      described_class.const_get('LOG_DEPRECATIONS_ONLY_ONCE').each_value { |only_once| only_once.send(:reset_ran_once_state_for_tests) }
     end
 
     context 'when deprecated env is set in ENV' do