add span name generator for otelgin option

CHANGELOG.md

@@ -11,6 +11,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Added
 
 - Add the new `go.opentelemetry.io/contrib/instrgen` package to provide auto-generated source code instrumentation. (#3068)
+- Add `SpanNameFormatter` option to package `go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin`. (#3343)
 
 ### Changed
 

instrumentation/github.com/gin-gonic/gin/otelgin/gintrace.go

@@ -73,7 +73,12 @@ func Middleware(service string, opts ...Option) gin.HandlerFunc {
 			oteltrace.WithAttributes(httpconv.ServerRequest(service, c.Request)...),
 			oteltrace.WithSpanKind(oteltrace.SpanKindServer),
 		}
-		spanName := c.FullPath()
+		var spanName string
+		if cfg.SpanNameFormatter == nil {
+			spanName = c.FullPath()
+		} else {
+			spanName = cfg.SpanNameFormatter(c.Request)
+		}
 		if spanName == "" {
 			spanName = fmt.Sprintf("HTTP %s route not found", c.Request.Method)
 		} else {

instrumentation/github.com/gin-gonic/gin/otelgin/option.go

@@ -24,15 +24,19 @@ import (
 )
 
 type config struct {
-	TracerProvider oteltrace.TracerProvider
-	Propagators    propagation.TextMapPropagator
-	Filters        []Filter
+	TracerProvider    oteltrace.TracerProvider
+	Propagators       propagation.TextMapPropagator
+	Filters           []Filter
+	SpanNameFormatter SpanNameFormatter
 }
 
 // Filter is a predicate used to determine whether a given http.request should
 // be traced. A Filter must return true if the request should be traced.
 type Filter func(*http.Request) bool
 
+// SpanNameFormatter is used to set span name by http.request.
+type SpanNameFormatter func(r *http.Request) string
+
 // Option specifies instrumentation configuration options.
 type Option interface {
 	apply(*config)
@@ -76,3 +80,11 @@ func WithFilter(f ...Filter) Option {
 		c.Filters = append(c.Filters, f...)
 	})
 }
+
+// WithSpanNameFormatter takes a function that will be called on every
+// request and the returned string will become the Span Name.
+func WithSpanNameFormatter(f func(r *http.Request) string) Option {
+	return optionFunc(func(c *config) {
+		c.SpanNameFormatter = f
+	})
+}