From 2d6e69226be20a7f001c7792bda8df68d90287c6 Mon Sep 17 00:00:00 2001
From: Carl Bergquist <carl.bergquist@gmail.com>
Date: Fri, 10 Jun 2022 10:56:55 +0200
Subject: [PATCH] Instrumentation: Add feature toggle for logging requests
 instrumented as unknown (#50566)

Signed-off-by: bergquist <carl.bergquist@gmail.com>
---
 .../src/types/featureToggles.gen.ts            |  1 +
 pkg/middleware/request_metrics.go              | 18 ++++++++++++------
 pkg/services/featuremgmt/registry.go           |  5 +++++
 pkg/services/featuremgmt/toggles_gen.go        |  4 ++++
 4 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/packages/grafana-data/src/types/featureToggles.gen.ts b/packages/grafana-data/src/types/featureToggles.gen.ts
index e3b794c181a..3cc6fa27b0b 100644
--- a/packages/grafana-data/src/types/featureToggles.gen.ts
+++ b/packages/grafana-data/src/types/featureToggles.gen.ts
@@ -58,4 +58,5 @@ export interface FeatureToggles {
   prometheusWideSeries?: boolean;
   canvasPanelNesting?: boolean;
   cloudMonitoringExperimentalUI?: boolean;
+  logRequestsInstrumentedAsUnknown?: boolean;
 }
diff --git a/pkg/middleware/request_metrics.go b/pkg/middleware/request_metrics.go
index 654271e92cd..fb6c7a57117 100644
--- a/pkg/middleware/request_metrics.go
+++ b/pkg/middleware/request_metrics.go
@@ -6,6 +6,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/infra/metrics"
 	"github.com/grafana/grafana/pkg/infra/tracing"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
@@ -46,6 +47,8 @@ func init() {
 
 // RequestMetrics is a middleware handler that instruments the request.
 func RequestMetrics(features featuremgmt.FeatureToggles) web.Handler {
+	log := log.New("middleware.request-metrics")
+
 	return func(res http.ResponseWriter, req *http.Request, c *web.Context) {
 		if strings.HasPrefix(c.Req.URL.Path, "/public/") || c.Req.URL.Path == "robots.txt" || c.Req.URL.Path == "/metrics" {
 			c.Next()
@@ -58,15 +61,18 @@ func RequestMetrics(features featuremgmt.FeatureToggles) web.Handler {
 		defer httpRequestsInFlight.Dec()
 		c.Next()
 
-		handler := "unknown"
-
-		if routeOperation, exists := RouteOperationNameFromContext(c.Req.Context()); exists {
-			handler = routeOperation
-		}
-
 		status := rw.Status()
 		code := sanitizeCode(status)
 
+		handler := "unknown"
+		if routeOperation, exists := RouteOperationNameFromContext(c.Req.Context()); exists {
+			handler = routeOperation
+		} else {
+			if features.IsEnabled(featuremgmt.FlagLogRequestsInstrumentedAsUnknown) {
+				log.Warn("request instrumented as unknown", "path", c.Req.URL.Path, "status_code", status)
+			}
+		}
+
 		// avoiding the sanitize functions for in the new instrumentation
 		// since they dont make much sense. We should remove them later.
 		histogram := httpRequestDurationHistogram.
diff --git a/pkg/services/featuremgmt/registry.go b/pkg/services/featuremgmt/registry.go
index 623ea09178f..1490b6be669 100644
--- a/pkg/services/featuremgmt/registry.go
+++ b/pkg/services/featuremgmt/registry.go
@@ -237,5 +237,10 @@ var (
 			State:        FeatureStateAlpha,
 			FrontendOnly: true,
 		},
+		{
+			Name:        "logRequestsInstrumentedAsUnknown",
+			Description: "Logs the path for requests that are instrumented as unknown",
+			State:       FeatureStateAlpha,
+		},
 	}
 )
diff --git a/pkg/services/featuremgmt/toggles_gen.go b/pkg/services/featuremgmt/toggles_gen.go
index a911fcbacae..bbc6b55dfd7 100644
--- a/pkg/services/featuremgmt/toggles_gen.go
+++ b/pkg/services/featuremgmt/toggles_gen.go
@@ -174,4 +174,8 @@ const (
 	// FlagCloudMonitoringExperimentalUI
 	// Use grafana-experimental UI in Cloud Monitoring
 	FlagCloudMonitoringExperimentalUI = "cloudMonitoringExperimentalUI"
+
+	// FlagLogRequestsInstrumentedAsUnknown
+	// Logs the path for requests that are instrumented as unknown
+	FlagLogRequestsInstrumentedAsUnknown = "logRequestsInstrumentedAsUnknown"
 )