feature: Add trace.Region in existing tracing middlewares

changelog/@unreleased/pr-764.v2.yml

@@ -0,0 +1,5 @@
+type: feature
+feature:
+  description: Add trace.Region in existing tracing middlewares
+  links:
+  - https://github.com/palantir/witchcraft-go-server/pull/764

witchcraft/internal/middleware/request.go

@@ -16,6 +16,7 @@ package middleware
 
 import (
 	"net/http"
+	"runtime/trace"
 	"strconv"
 	"time"
 
@@ -137,7 +138,8 @@ func NewRequestExtractIDs(
 
 		// retrieve existing trace info from request and create a span
 		reqSpanContext := b3.SpanExtractor(req)()
-		span := tracer.StartSpan("witchcraft-go-server request middleware",
+		spanName := "witchcraft-go-server request middleware"
+		span := tracer.StartSpan(spanName,
 			wtracing.WithParentSpanContext(reqSpanContext),
 			wtracing.WithSpanTag("http.method", req.Method),
 			wtracing.WithSpanTag("http.useragent", req.UserAgent()),
@@ -150,6 +152,9 @@ func NewRequestExtractIDs(
 		// update request with new context
 		req = req.WithContext(ctx)
 
+		// Create a go execution trace region for the request middleware
+		defer trace.StartRegion(ctx, spanName).End()
+
 		// delegate to the next handler
 		lrw := toLoggingResponseWriter(rw)
 		next.ServeHTTP(lrw, req)

witchcraft/internal/middleware/route.go

@@ -17,6 +17,7 @@ package middleware
 import (
 	"context"
 	"net/http"
+	"runtime/trace"
 	"time"
 
 	"github.com/palantir/conjure-go-runtime/v2/conjure-go-contract/errors"
@@ -109,6 +110,9 @@ func NewRouteLogTraceSpan() wrouter.RouteHandlerMiddleware {
 		req = req.WithContext(ctx)
 		b3.SpanInjector(req)(span.Context())
 
+		// Create a go execution trace region for the route
+		defer trace.StartRegion(ctx, spanName).End()
+
 		next(rw, req, reqVals)
 	}
 }