instrumentation.rb in opentelemetry-instrumentation-sinatra-0.24.0

- old
+ new
@@ -7,20 +7,53 @@
 require_relative 'extensions/tracer_extension'
 
 module OpenTelemetry
   module Instrumentation
     module Sinatra
-      # The Instrumentation class contains logic to detect and install the Sinatra
-      # instrumentation
+      # The {OpenTelemetry::Instrumentation::Sinatra::Instrumentation} class contains logic to detect and install the Sinatra instrumentation
+      #
+      # Installation and configuration of this instrumentation is done within the
+      # {https://www.rubydoc.info/gems/opentelemetry-sdk/OpenTelemetry/SDK#configure-instance_method OpenTelemetry::SDK#configure}
+      # block, calling {https://www.rubydoc.info/gems/opentelemetry-sdk/OpenTelemetry%2FSDK%2FConfigurator:use use()}
+      # or {https://www.rubydoc.info/gems/opentelemetry-sdk/OpenTelemetry%2FSDK%2FConfigurator:use_all use_all()}.
+      #
+      # ## Configuration keys and options
+      #
+      # ### `:install_rack`
+      #
+      # Default is `true`. Specifies whether or not to install the Rack instrumentation as part of installing the Sinatra instrumentation.
+      # This is useful in cases where you have multiple Rack applications but want to manually specify where to insert the tracing middleware.
+      #
+      # @example Manually install Rack instrumentation.
+      #   OpenTelemetry::SDK.configure do |c|
+      #     c.use_all({
+      #       'OpenTelemetry::Instrumentation::Rack' => { },
+      #       'OpenTelemetry::Instrumentation::Sinatra' => {
+      #         install_rack: false
+      #       },
+      #     })
+      #   end
+      #
       class Instrumentation < OpenTelemetry::Instrumentation::Base
-        install do |_|
-          OpenTelemetry::Instrumentation::Rack::Instrumentation.instance.install({})
+        install do |config|
+          OpenTelemetry::Instrumentation::Rack::Instrumentation.instance.install({}) if config[:install_rack]
 
+          unless OpenTelemetry::Instrumentation::Rack::Instrumentation.instance.installed?
+            OpenTelemetry.logger.warn('Rack instrumentation is required for Sinatra but not installed. Please see the docs for more details: https://opentelemetry.io/docs/languages/ruby/libraries/')
+          end
+
           ::Sinatra::Base.register Extensions::TracerExtension
         end
 
+        option :install_rack, default: true, validate: :boolean
+
         present do
           defined?(::Sinatra)
+        end
+
+        def install_middleware(app)
+          app.use(*OpenTelemetry::Instrumentation::Rack::Instrumentation.instance.middleware_args) if config[:install_rack]
+          app.use(Middlewares::TracerMiddleware)
         end
       end
     end
   end
 end