fix(ffe/ruby): support provider-managed configuration startup

utils/build/docker/ruby/parametric/server.rb

@@ -45,14 +45,8 @@
   c.logger.instance = Logger.new(STDOUT) # Make sure logs are available for inspection from outside the container.
 end
 
-if Datadog::Core::Remote.active_remote
-  # TODO: Remove this whole `if` condition if remote configuration is started by default.
-  if Datadog::Core::Remote.active_remote.started?
-    raise 'Remote Configuration worker already started! Remove this check and `Datadog::Core::Remote.active_remote.start` below.'
-  end
-
-  Datadog::Core::Remote.active_remote.start
-end
+remote = Datadog::Core::Remote.active_remote
+remote&.start unless remote&.started?
 
 def otel_tracer
   OpenTelemetry.tracer_provider.tracer('otel-tracer')
@@ -842,22 +836,27 @@ def extract_http_headers(headers)
   end
 end
 
-def handle_ffe_start(req, res)
-  OpenFeature::SDK.set_provider(Datadog::OpenFeature::Provider.new)
+def handle_ffe_start(_req, res)
+  provider = Datadog::OpenFeature::Provider.new
+  feature_flagging_configured = %w[
+    DD_FEATURE_FLAGS_ENABLED
+    DD_FEATURE_FLAGS_CONFIGURATION_SOURCE
+    DD_FEATURE_FLAGS_CONFIGURATION_SOURCE_AGENTLESS_BASE_URL
+    DD_FEATURE_FLAGS_CONFIGURATION_SOURCE_AGENTLESS_POLL_INTERVAL_SECONDS
+    DD_FEATURE_FLAGS_CONFIGURATION_SOURCE_AGENTLESS_REQUEST_TIMEOUT_SECONDS
+    DD_EXPERIMENTAL_FLAGGING_PROVIDER_ENABLED
+    DD_EXPERIMENTAL_FLAGGING_PROVIDER_INITIALIZATION_TIMEOUT_MS
+  ].any? { |name| ENV.key?(name) }
 
-  # NOTE: There is no set_provider_and_wait in Ruby OpenFeature::SDK, but this is
-  #       a subject to change.
-  #
-  #       Remote Configuration will be received at this point because of the short
-  #       polling delay.
-  10.times do
-    evaluator = Datadog::OpenFeature.engine.instance_variable_get(:@evaluator)
-    break unless evaluator.instance_variable_get(:@configuration).nil?
-
-    sleep 0.5
+  if feature_flagging_configured
+    OpenFeature::SDK.set_provider_and_wait(provider)
+  else
+    OpenFeature::SDK.set_provider(provider)
   end
-
   res.write({}.to_json)
+rescue => e
+  res.status = 500
+  res.write({error: e.message}.to_json)
 end
 
 def handle_ffe_evaluation(req, res)

utils/build/docker/ruby/rails72/app/controllers/open_feature_controller.rb

@@ -4,15 +4,10 @@ class OpenFeatureController < ApplicationController
   skip_before_action :verify_authenticity_token
 
   def start
-    OpenFeature::SDK.set_provider(Datadog::OpenFeature::Provider.new)
-
-    # NOTE: There is no set_provider_and_wait in OpenFeature::SDK
-    loop do
-      break unless Datadog::OpenFeature.evaluator.ufc_json.nil?
-      sleep 0.1
-    end
-
+    OpenFeature::SDK.set_provider_and_wait(Datadog::OpenFeature::Provider.new)
     render json: {}
+  rescue => e
+    render json: {error: e.message}, status: :internal_server_error
   end
 
   def evaluate