Added null guards to 'Process' when processing an incoming span (#1723)

Signed-off-by: Juraci Paixão Kröhling <[email protected]>

cmd/collector/app/metrics.go

@@ -244,10 +244,13 @@ func (m *SpanProcessorMetrics) GetCountsForFormat(spanFormat SpanFormat, transpo
 // reportServiceNameForSpan determines the name of the service that emitted
 // the span and reports a counter stat.
 func (m metricsBySvc) ReportServiceNameForSpan(span *model.Span) {
-	serviceName := span.Process.ServiceName
-	if serviceName == "" {
-		return
+	var serviceName string
+	if nil == span.Process || len(span.Process.ServiceName) == 0 {
+		serviceName = "__unknown"
+	} else {
+		serviceName = span.Process.ServiceName
 	}
+
 	m.countSpansByServiceName(serviceName, span.Flags.IsDebug())
 	if span.ParentSpanID() == 0 {
 

cmd/collector/app/span_processor.go

@@ -109,6 +109,12 @@ func (sp *spanProcessor) Stop() {
 }
 
 func (sp *spanProcessor) saveSpan(span *model.Span) {
+	if nil == span.Process {
+		sp.logger.Error("process is empty for the span")
+		sp.metrics.SavedErrBySvc.ReportServiceNameForSpan(span)
+		return
+	}
+
 	startTime := time.Now()
 	if err := sp.spanWriter.WriteSpan(span); err != nil {
 		sp.logger.Error("Failed to save span", zap.Error(err))

cmd/collector/app/span_processor_test.go

@@ -299,3 +299,19 @@ func TestSpanProcessorBusy(t *testing.T) {
 	assert.Error(t, err, "expcting busy error")
 	assert.Nil(t, res)
 }
+
+func TestSpanProcessorWithNilProcess(t *testing.T) {
+	mb := metricstest.NewFactory(time.Hour)
+	serviceMetrics := mb.Namespace(metrics.NSOptions{Name: "service", Tags: nil})
+
+	w := &fakeSpanWriter{}
+	p := NewSpanProcessor(w, Options.ServiceMetrics(serviceMetrics)).(*spanProcessor)
+	defer p.Stop()
+
+	p.saveSpan(&model.Span{})
+
+	expected := []metricstest.ExpectedMetric{{
+		Name: "service.spans.saved-by-svc|debug=false|result=err|svc=__unknown", Value: 1,
+	}}
+	mb.AssertCounterMetrics(t, expected...)
+}