feat: support julienschmidt/httprouter

_integration-tests/go.mod

@@ -38,6 +38,7 @@ require (
 	github.com/hashicorp/vault/api v1.15.0
 	github.com/jackc/pgx/v5 v5.7.1
 	github.com/jinzhu/gorm v1.9.16
+	github.com/julienschmidt/httprouter v1.3.0
 	github.com/labstack/echo/v4 v4.12.0
 	github.com/mattn/go-sqlite3 v1.14.22
 	github.com/redis/go-redis/v9 v9.7.0

_integration-tests/go.sum

@@ -1429,6 +1429,7 @@ github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHm
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/jstemmer/go-junit-report v0.9.1/go.mod h1:Brl9GWCQeLvo8nXZwPNNblvFj/XSXhF0NWZEnDohbsk=
 github.com/juju/qthttptest v0.1.1/go.mod h1:aTlAv8TYaflIiTDIQYzxnl1QdPjAg8Q8qJMErpKy6A4=
+github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/jung-kurt/gofpdf v1.0.0/go.mod h1:7Id9E/uU8ce6rXgefFLlgrJj/GYY22cpxn+r32jIOes=
 github.com/jung-kurt/gofpdf v1.0.3-0.20190309125859-24315acbbda5/go.mod h1:7Id9E/uU8ce6rXgefFLlgrJj/GYY22cpxn+r32jIOes=

_integration-tests/tests/julienschmidt_httprouter/julienschmidt_httprouter.go

@@ -0,0 +1,102 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2023-present Datadog, Inc.
+
+//go:build integration
+
+package julienschmidt_httprouter
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/julienschmidt/httprouter"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"datadoghq.dev/orchestrion/_integration-tests/utils"
+	"datadoghq.dev/orchestrion/_integration-tests/validator/trace"
+)
+
+type TestCase struct {
+	*http.Server
+}
+
+func (tc *TestCase) Setup(t *testing.T) {
+	router := httprouter.New()
+	router.GET("/ping", func(w http.ResponseWriter, _ *http.Request, _ httprouter.Params) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, err := io.WriteString(w, `{"message": "pong"}`)
+		assert.NoError(t, err)
+	})
+	tc.Server = &http.Server{
+		Addr:         "127.0.0.1:" + utils.GetFreePort(t),
+		Handler:      router,
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 10 * time.Second,
+	}
+	go func() { assert.ErrorIs(t, tc.Server.ListenAndServe(), http.ErrServerClosed) }()
+}
+
+func (tc *TestCase) Run(t *testing.T) {
+	resp, err := http.Get(fmt.Sprintf("http://%s/ping", tc.Server.Addr))
+	require.NoError(t, err)
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+}
+
+func (tc *TestCase) Teardown(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	require.NoError(t, tc.Server.Shutdown(ctx))
+}
+
+func (*TestCase) ExpectedTraces() trace.Traces {
+	return trace.Traces{
+		{
+			Tags: map[string]any{
+				"name":     "http.request",
+				"resource": "GET /ping",
+				"type":     "http",
+				"service":  "julienschmidt_httprouter.test",
+			},
+			Meta: map[string]string{
+				"component": "net/http",
+				"span.kind": "client",
+			},
+			Children: trace.Traces{
+				{
+					Tags: map[string]any{
+						"name":     "http.request",
+						"resource": "GET /ping",
+						"type":     "web",
+						"service":  "julienschmidt_httprouter.test",
+					},
+					Meta: map[string]string{
+						"component": "net/http",
+						"span.kind": "server",
+					},
+					Children: trace.Traces{
+						{
+							Tags: map[string]any{
+								"name":     "http.request",
+								"resource": "GET /ping",
+								"type":     "web",
+								"service":  "http.router",
+							},
+							Meta: map[string]string{
+								"component": "julienschmidt/httprouter",
+								"span.kind": "server",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}

_integration-tests/tests/mux/mux.go

@@ -27,13 +27,12 @@ type TestCase struct {
 }
 
 func (tc *TestCase) Setup(t *testing.T) {
-	mux := mux.NewRouter()
+	router := mux.NewRouter()
 	tc.Server = &http.Server{
 		Addr:    "127.0.0.1:" + utils.GetFreePort(t),
-		Handler: mux,
+		Handler: router,
 	}
-
-	mux.HandleFunc("/ping", func(w http.ResponseWriter, _ *http.Request) {
+	router.HandleFunc("/ping", func(w http.ResponseWriter, _ *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
 		w.WriteHeader(http.StatusOK)
 		_, err := io.WriteString(w, `{"message": "pong"}`)
@@ -65,19 +64,56 @@ func (tc *TestCase) ExpectedTraces() trace.Traces {
 				"name":     "http.request",
 				"resource": "GET /ping",
 				"type":     "http",
+				"service":  "mux.test",
 			},
 			Meta: map[string]string{
-				"http.url": url,
+				"http.url":  url,
+				"component": "net/http",
+				"span.kind": "client",
 			},
 			Children: trace.Traces{
 				{
 					Tags: map[string]any{
 						"name":     "http.request",
 						"resource": "GET /ping",
 						"type":     "web",
+						"service":  "mux.test",
 					},
 					Meta: map[string]string{
-						"http.url": url,
+						"http.url":  url,
+						"component": "net/http",
+						"span.kind": "server",
+					},
+					Children: trace.Traces{
+						{
+							Tags: map[string]any{
+								"name":     "http.request",
+								"resource": "GET /ping",
+								"type":     "web",
+								"service":  "mux.router",
+							},
+							Meta: map[string]string{
+								"http.url":  url,
+								"component": "gorilla/mux",
+								"span.kind": "server",
+							},
+							Children: trace.Traces{
+								{
+									// FIXME: this span shouldn't exist
+									Tags: map[string]any{
+										"name":     "http.request",
+										"resource": "GET /ping",
+										"type":     "web",
+										"service":  "mux.router",
+									},
+									Meta: map[string]string{
+										"http.url":  url,
+										"component": "net/http",
+										"span.kind": "server",
+									},
+								},
+							},
+						},
 					},
 				},
 			},

internal/injector/builtin/yaml/http/julienschmidt_httprouter.yml

@@ -0,0 +1,89 @@
+# Unless explicitly stated otherwise all files in this repository are licensed
+# under the Apache License Version 2.0.
+# This product includes software developed at Datadog (https://www.datadoghq.com/).
+# Copyright 2023-present Datadog, Inc.
+---
+# yaml-language-server: $schema=../../../../../docs/static/schema.json
+meta:
+  name: github.com/julienschmidt/httprouter
+  description: A high performance HTTP request router that scales well.
+  icon: at-symbol
+
+aspects:
+  - id: Add fields to httprouter.Router
+    join-point:
+      struct-definition: github.com/julienschmidt/httprouter.Router
+    advice:
+      - inject-declarations:
+          imports:
+            tracing: "gopkg.in/DataDog/dd-trace-go.v1/contrib/julienschmidt/httprouter/internal/tracing"
+          lang: go1.18
+          template: |-
+            type __dd_wRouter struct {
+              *Router
+            }
+
+            func __dd_wrapRouter(r *Router) tracing.Router {
+              return &__dd_wRouter{r}
+            }
+
+            func (w __dd_wRouter) Lookup(method string, path string) (any, []tracing.Param, bool) {
+              h, params, ok := w.Router.Lookup(method, path)
+              return h, __dd_wrapParams(params), ok
+            }
+
+            type __dd_wParam struct {
+              Param
+            }
+
+            func __dd_wrapParams(params Params) []tracing.Param {
+              wParams := make([]tracing.Param, len(params))
+              for i, p := range params {
+                wParams[i] = __dd_wParam{p}
+              }
+              return wParams
+            }
+
+            func (w __dd_wParam) GetKey() string {
+              return w.Key
+            }
+
+            func (w __dd_wParam) GetValue() string {
+              return w.Value
+            }
+
+            func __dd_init(r *Router) {
+              if r.__dd_config != nil {
+                return
+              }
+              r.__dd_config = tracing.NewConfig()
+              return
+            }
+
+      - add-struct-field:
+          name: __dd_config
+          type: "*gopkg.in/DataDog/dd-trace-go.v1/contrib/julienschmidt/httprouter/internal/tracing.Config"
+
+  - id: Trace httprouter.Router#ServeHTTP
+    join-point:
+      function-body:
+        function:
+          - receiver: "*github.com/julienschmidt/httprouter.Router"
+          - name: ServeHTTP
+    advice:
+      - prepend-statements:
+          imports:
+            tracing:  "gopkg.in/DataDog/dd-trace-go.v1/contrib/julienschmidt/httprouter/internal/tracing"
+          template: |-
+            {{- $r := .Function.Receiver -}}
+            {{- $w := .Function.Argument 0 -}}
+            {{- $req := .Function.Argument 1 -}}
+            __dd_init({{ $r }})
+
+            tw, treq, afterHandle, handled := tracing.BeforeHandle({{ $r }}.__dd_config, {{ $r }}, __dd_wrapRouter, {{ $w }}, {{ $req }})
+            {{ $w }} = tw
+            {{ $req }} = treq
+            defer afterHandle()
+            if handled {
+              return
+            }