Instrumentation: Add status_source label to request metrics/logs (#74114)

Ref #68480

Co-authored-by: Giuseppe Guerra <giuseppe.guerra@grafana.com>

pkg/util/proxyutil/reverse_proxy.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	glog "github.com/grafana/grafana/pkg/infra/log"
+	"github.com/grafana/grafana/pkg/middleware/requestmeta"
 	"github.com/grafana/grafana/pkg/services/contexthandler"
 )
 
@@ -103,6 +104,8 @@ func modifyResponse(logger glog.Logger) func(resp *http.Response) error {
 
 		SetProxyResponseHeaders(resp.Header)
 		SetViaHeader(resp.Header, resp.ProtoMajor, resp.ProtoMinor)
+
+		requestmeta.WithStatusSource(resp.Request.Context(), resp.StatusCode)
 		return nil
 	}
 }
@@ -120,6 +123,7 @@ type timeoutError interface {
 func errorHandler(logger glog.Logger) func(http.ResponseWriter, *http.Request, error) {
 	return func(w http.ResponseWriter, r *http.Request, err error) {
 		ctxLogger := logger.FromContext(r.Context())
+		requestmeta.WithDownstreamStatusSource(r.Context())
 
 		if errors.Is(err, context.Canceled) {
 			ctxLogger.Debug("Proxy request cancelled by client")