[WIP] Tracing Remote Configuration

lib/datadog/core/remote/client/capabilities.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require_relative '../../../appsec/remote'
+require_relative '../../../tracing/remote'
 
 module Datadog
   module Core
@@ -28,6 +29,10 @@ def register(settings)
               register_products(Datadog::AppSec::Remote.products)
               register_receivers(Datadog::AppSec::Remote.receivers)
             end
+
+            register_capabilities(Datadog::Tracing::Remote.capabilities)
+            register_products(Datadog::Tracing::Remote.products)
+            register_receivers(Datadog::Tracing::Remote.receivers)
           end
 
           def register_capabilities(capabilities)

lib/datadog/tracing/remote.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require_relative '../core/remote/dispatcher'
+
+module Datadog
+  module Tracing
+    # Remote configuration declaration
+    module Remote
+      class ReadError < StandardError; end
+
+      class << self
+        PRODUCT = 'APM_LIBRARY'
+
+        def products
+          [PRODUCT]
+        end
+
+        def capabilities
+          []
+        end
+
+        def receivers
+          receiver do |repository, _changes|
+            config = []
+
+            # DEV: Filter our by product. Given it will be very common
+            # DEV: we can filter this out before we receive the data in this method.
+            # DEV: Apply this refactor to AppSec as well if implemented.
+            repository.contents.each do |content|
+              case content.path.product
+              when PRODUCT
+                config << parse_content(content)
+              end
+            end
+
+            # TODO: Make the magic happen!
+            # Tracing::Component.reconfigure(config)
+          end
+        end
+
+        def receiver(products = [PRODUCT], &block)
+          matcher = Core::Remote::Dispatcher::Matcher::Product.new(products)
+          [Core::Remote::Dispatcher::Receiver.new(matcher) do |repository, changes|
+            changes.each do |change|
+              Datadog.logger.debug { "remote config change: '#{change.path}'" }
+            end
+            yield(repository, changes)
+          end]
+        end
+
+        private
+
+        def parse_content(content)
+          data = content.data.read
+
+          content.data.rewind
+
+          raise ReadError, 'EOF reached' if data.nil?
+
+          JSON.parse(data)
+        end
+      end
+    end
+  end
+end