add gorilla mux

contrib/gorilla/mux/handler.go

@@ -0,0 +1,26 @@
+package mux
+
+import (
+	"net/http"
+
+	ddspanname "github.com/RangelReale/opentelemetry-go-datadog-spanname"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// NewHandler should be used with [github.com/gorilla/mux].
+func NewHandler(opts ...Option) trace.TracerProvider {
+	optns := options{
+		operationName: "http.request",
+	}
+	for _, opt := range opts {
+		opt(&optns)
+	}
+	return ddspanname.NewTracerProvider(optns.operationName,
+		ddspanname.WithTracerProvider(optns.tracerProvider))
+}
+
+// SpanNameFormatter should be used with [otelmux.WithSpanNameFormatter] because
+// the default formatter only outputs the route without the http method.
+func SpanNameFormatter(routeName string, r *http.Request) string {
+	return r.Method + " " + routeName
+}

contrib/gorilla/mux/option.go

@@ -0,0 +1,22 @@
+package mux
+
+import "go.opentelemetry.io/otel/trace"
+
+type options struct {
+	tracerProvider trace.TracerProvider
+	operationName  string
+}
+
+type Option func(*options)
+
+func WithTracerProvider(tracerProvider trace.TracerProvider) Option {
+	return func(o *options) {
+		o.tracerProvider = tracerProvider
+	}
+}
+
+func WithOperationName(name string) Option {
+	return func(o *options) {
+		o.operationName = name
+	}
+}