From 00cb0d0421f26f33b90c9431eeeb8e642e82074b Mon Sep 17 00:00:00 2001
From: Ryan D McGuire <ryand_mcguire@sweetwater.com>
Date: Wed, 27 Aug 2025 10:04:05 -0400
Subject: [PATCH] refactors OpenTelemetry HTTP instrumentation by centralizing
 handler wrapping, adding span name formatting, and filtering health and
 metrics paths.

---
 pkg/srv/http/http.go | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/pkg/srv/http/http.go b/pkg/srv/http/http.go
index 78bbea6..b87defc 100644
--- a/pkg/srv/http/http.go
+++ b/pkg/srv/http/http.go
@@ -39,19 +39,12 @@ func prepHTTPServer(opts *opts.AppHTTP) *http.Server {
 		mux = &http.ServeMux{}
 	)
 
-	// NOTE: Wraps handle func with otelhttp handler and
-	// inserts route tag
-	otelHandleFunc := func(pattern string, handlerFunc func(http.ResponseWriter, *http.Request)) {
-		handler := otelhttp.WithRouteTag(pattern, http.HandlerFunc(handlerFunc))
-		mux.Handle(pattern, handler) // Associate pattern with handler
-	}
-
 	healthChecks := handleHealthCheckFunc(opts.Ctx, opts.HealthChecks...)
-	otelHandleFunc("/health", healthChecks)
-	otelHandleFunc("/", healthChecks)
+	mux.HandleFunc("/health", healthChecks)
+	mux.HandleFunc("/", healthChecks)
 
 	for _, f := range opts.Funcs {
-		otelHandleFunc(f.Path, f.HandlerFunc)
+		mux.HandleFunc(f.Path, f.HandlerFunc)
 	}
 
 	// Prometheus metrics endpoint
@@ -74,12 +67,12 @@ func prepHTTPServer(opts *opts.AppHTTP) *http.Server {
 		if h.StripPrefix {
 			h.Handler = http.StripPrefix(h.Prefix[:len(h.Prefix)-1], h.Handler)
 		}
-		mux.Handle(h.Prefix, h.Handler)
+		mux.Handle(h.Prefix, otelhttp.WithRouteTag(h.Prefix, h.Handler))
 	}
 
-	// Add OTEL, skip health-check spans
-	// NOTE: Add any other span exclusions here
+	// Add OTEL instrumentation, filter noise, set span names
 	handler := otelhttp.NewHandler(mux, "/",
+		// TODO: Make configurable similar to config.http.LogExcludePathRegexps
 		otelhttp.WithFilter(func(r *http.Request) bool {
 			switch r.URL.Path {
 			case "/health":
@@ -89,6 +82,14 @@ func prepHTTPServer(opts *opts.AppHTTP) *http.Server {
 			default:
 				return true
 			}
+		}),
+		otelhttp.WithSpanNameFormatter(func(operation string, r *http.Request) string {
+			_, pattern := mux.Handler(r)
+			if pattern != "" {
+				return pattern // Use the route pattern as the span name, e.g., "/users/{id}"
+			}
+			// Fallback to the default naming convention if no route is found.
+			return operation + " " + r.URL.Path
 		}))
 
 	// Set timeouts from defaults, override