contrib/gofiber/fiber.v2: add possibility to exclude spans generation…

… for specific requests (#2583)

Co-authored-by: nsakharenko <[email protected]>
Co-authored-by: Dario Castañé <[email protected]>

contrib/gofiber/fiber.v2/fiber.go

@@ -37,6 +37,10 @@ func Middleware(opts ...Option) func(c *fiber.Ctx) error {
 	}
 	log.Debug("gofiber/fiber.v2: Middleware: %#v", cfg)
 	return func(c *fiber.Ctx) error {
+		if cfg.ignoreRequest(c) {
+			return c.Next()
+		}
+
 		opts := []ddtrace.StartSpanOption{
 			tracer.SpanType(ext.SpanTypeWeb),
 			tracer.ServiceName(cfg.serviceName),

contrib/gofiber/fiber.v2/fiber_test.go

@@ -332,3 +332,33 @@ func TestNamingSchema(t *testing.T) {
 	})
 	namingschematest.NewHTTPServerTest(genSpans, "fiber")(t)
 }
+
+func TestIgnoreRequest(t *testing.T) {
+	assert := assert.New(t)
+	mt := mocktracer.Start()
+	defer mt.Stop()
+
+	router := fiber.New()
+	router.Use(
+		Middleware(
+			WithIgnoreRequest(func(ctx *fiber.Ctx) bool {
+				return ctx.Method() == "GET" && ctx.Path() == "/ignore"
+			}),
+		),
+	)
+	router.Get("/ignore", func(c *fiber.Ctx) error {
+		return c.SendString("IAMALIVE")
+	})
+
+	r := httptest.NewRequest("GET", "/ignore", nil)
+
+	// do and verify the request
+	resp, err := router.Test(r)
+	assert.Equal(nil, err)
+	defer resp.Body.Close()
+	assert.Equal(resp.StatusCode, 200)
+
+	spans := mt.FinishedSpans()
+
+	assert.Len(spans, 0)
+}

contrib/gofiber/fiber.v2/option.go

@@ -25,6 +25,7 @@ type config struct {
 	spanOpts      []ddtrace.StartSpanOption // additional span options to be applied
 	analyticsRate float64
 	resourceNamer func(*fiber.Ctx) string
+	ignoreRequest func(*fiber.Ctx) bool
 }
 
 // Option represents an option that can be passed to NewRouter.
@@ -35,6 +36,7 @@ func defaults(cfg *config) {
 	cfg.spanName = namingschema.OpName(namingschema.HTTPServer)
 	cfg.isStatusError = isServerError
 	cfg.resourceNamer = defaultResourceNamer
+	cfg.ignoreRequest = defaultIgnoreRequest
 
 	if internal.BoolEnv("DD_TRACE_FIBER_ENABLED", false) {
 		cfg.analyticsRate = 1.0
@@ -97,11 +99,23 @@ func WithResourceNamer(fn func(*fiber.Ctx) string) Option {
 	}
 }
 
+// WithIgnoreRequest specifies a function which will be used to
+// determining if the incoming HTTP request tracing should be skipped.
+func WithIgnoreRequest(fn func(*fiber.Ctx) bool) Option {
+	return func(cfg *config) {
+		cfg.ignoreRequest = fn
+	}
+}
+
 func defaultResourceNamer(c *fiber.Ctx) string {
 	r := c.Route()
 	return r.Method + " " + r.Path
 }
 
+func defaultIgnoreRequest(*fiber.Ctx) bool {
+	return false
+}
+
 func isServerError(statusCode int) bool {
 	return statusCode >= 500 && statusCode < 600
 }