adds tracing to rack requests and basic testing

lib/datadog/tracing/contrib/grape/endpoint.rb

@@ -94,7 +94,7 @@ def endpoint_run(name, start, finish, id, payload)
 
                 span.set_error(payload[:exception_object]) if exception_is_error?(payload[:exception_object])
 
-                integration_route = endpoint.env['grape.routing_args'][:route_info].pattern.path
+                integration_route = endpoint.env['grape.routing_args'][:route_info].pattern.origin
                 Thread.current[:datadog_http_routing] << [:grape, endpoint.env['SCRIPT_NAME'], integration_route]
 
                 # override the current span with this notification values

lib/datadog/tracing/contrib/rack/middlewares.rb

@@ -65,6 +65,9 @@ def compute_queue_time(env)
             end
           end
 
+          # rubocop:disable Metrics/CyclomaticComplexity
+          # rubocop:disable Metrics/PerceivedComplexity
+          # rubocop:disable Metrics/MethodLength
           def call(env)
             # Find out if this is rack within rack
             previous_request_span = env[Ext::RACK_ENV_REQUEST_SPAN]
@@ -102,20 +105,16 @@ def call(env)
             # call the rest of the stack
             status, headers, response = @app.call(env)
 
-            # TODO: might be wrong if say rails routed to sinatra but sinatra
-            #       fails to find a route, so I dumbly checked for 404?
             if status != 404 && (routed = Thread.current[:datadog_http_routing].last)
-              # TODO: array == bad, this should be a Struct
               last_script_name = routed[1]
               last_route = routed[2]
 
-              # TODO: I seem to have gathered that in some (all?) cases this
-              # should be nil when no route is found, which woudl cater for the
-              # note above
-              if last_route
-                composite_route = last_script_name + last_route
-                request_span.set_tag(Tracing::Metadata::Ext::HTTP::TAG_ROUTE, composite_route)
+              if last_script_name == '' && env['SCRIPT_NAME'] != ''
+                last_route = last_script_name
+                last_script_name = env['PATH_INFO']
               end
+
+              request_span.set_tag(Tracing::Metadata::Ext::HTTP::TAG_ROUTE, last_script_name + last_route) if last_route
             end
 
             [status, headers, response]
@@ -154,9 +153,6 @@ def call(env)
           # rubocop:enable Lint/RescueException
 
           # rubocop:disable Metrics/AbcSize
-          # rubocop:disable Metrics/CyclomaticComplexity
-          # rubocop:disable Metrics/PerceivedComplexity
-          # rubocop:disable Metrics/MethodLength
           def set_request_tags!(trace, request_span, env, status, headers, response, original_env)
             request_header_collection = Header::RequestHeaderCollection.new(env)
 

lib/datadog/tracing/contrib/rails/patcher.rb

@@ -15,7 +15,7 @@ module Rails
         module JourneyRouterPatch
           def find_routes(*args, **kwargs)
             result = super
-            integration_route = result.first[2].path.spec.to_s if result.any?
+            integration_route = result.first[2].path.spec.to_s.gsub(/\(\.:format\)/, '') if result.any?
             Thread.current[:datadog_http_routing] << [:rails, args.first.env['SCRIPT_NAME'], integration_route]
             result
           end
@@ -52,6 +52,7 @@ def before_initialize(app)
               # Sometimes we don't want to activate middleware e.g. OpenTracing, etc.
               add_middleware(app) if Datadog.configuration.tracing[:rails][:middleware]
 
+              # Check rails version if this works
               ActionDispatch::Journey::Router.prepend(JourneyRouterPatch)
 
               Rails::LogInjection.configure_log_tags(app.config)

spec/datadog/tracing/contrib/rails/rack_spec.rb

@@ -144,6 +144,7 @@ def internal_server_error
       expect(request_span.service).to eq(tracer.default_service)
       expect(request_span.resource).to eq('TestController#full')
       expect(request_span.get_tag('http.url')).to eq('/full')
+      expect(request_span.get_tag('http.route')).to eq('/full')
       expect(request_span.get_tag('http.method')).to eq('GET')
       expect(request_span.get_tag('http.status_code')).to eq('200')
       expect(request_span).to be_measured
@@ -379,6 +380,7 @@ def internal_server_error
       expect(request_span.span_type).to eq('web')
       expect(request_span.resource).to eq('TestController#error')
       expect(request_span.get_tag('http.url')).to eq('/error')
+      expect(request_span.get_tag('http.route')).to eq('/error')
       expect(request_span.get_tag('http.method')).to eq('GET')
       expect(request_span.get_tag('http.status_code')).to eq('500')
       expect(request_span).to have_error
@@ -414,6 +416,7 @@ def internal_server_error
       expect(request_span.span_type).to eq('web')
       expect(request_span.resource).to eq('TestController#soft_error')
       expect(request_span.get_tag('http.url')).to eq('/soft_error')
+      expect(request_span.get_tag('http.route')).to eq('/soft_error')
       expect(request_span.get_tag('http.method')).to eq('GET')
       expect(request_span.get_tag('http.status_code')).to eq('520')
       expect(request_span).to have_error
@@ -449,6 +452,7 @@ def internal_server_error
       expect(request_span.span_type).to eq('web')
       expect(request_span.resource).to eq('TestController#sub_error')
       expect(request_span.get_tag('http.url')).to eq('/sub_error')
+      expect(request_span.get_tag('http.route')).to eq('/sub_error')
       expect(request_span.get_tag('http.method')).to eq('GET')
       expect(request_span.get_tag('http.status_code')).to eq('500')
       expect(request_span).to have_error