suppress metrics if data was not fetched.

exporter.go

@@ -14,6 +14,9 @@ type exporter struct {
 	overviewMetrics     map[string]prometheus.Gauge
 	upMetric            prometheus.Gauge
 	exchangeMetrics     map[string]*prometheus.CounterVec
+	overviewFetched     bool
+	queuesFetched       bool
+	exchangesFetched    bool
 }
 
 func newExporter() *exporter {
@@ -31,6 +34,10 @@ func (e *exporter) fetchRabbit() {
 	rabbitMqQueueData, queueError := getStatsInfo(config, "queues")
 	exchangeData, exchangeError := getStatsInfo(config, "exchanges")
 
+	e.overviewFetched = overviewError == nil
+	e.queuesFetched = queueError == nil
+	e.exchangesFetched = exchangeError == nil
+
 	if overviewError != nil || queueError != nil || exchangeError != nil {
 		e.upMetric.Set(0)
 	} else {
@@ -98,6 +105,9 @@ func (e *exporter) Describe(ch chan<- *prometheus.Desc) {
 	for _, exchangeMetric := range e.exchangeMetrics {
 		exchangeMetric.Describe(ch)
 	}
+
+	e.upMetric.Describe(ch)
+	BuildInfo.Describe(ch)
 }
 
 func (e *exporter) Collect(ch chan<- prometheus.Metric) {
@@ -118,20 +128,25 @@ func (e *exporter) Collect(ch chan<- prometheus.Metric) {
 
 	e.upMetric.Collect(ch)
 
-	for _, gauge := range e.overviewMetrics {
-		gauge.Collect(ch)
+	if e.overviewFetched {
+		for _, gauge := range e.overviewMetrics {
+			gauge.Collect(ch)
+		}
 	}
 
-	for _, gaugevec := range e.queueMetricsGauge {
-		gaugevec.Collect(ch)
-	}
-	for _, countervec := range e.queueMetricsCounter {
-		countervec.Collect(ch)
+	if e.queuesFetched {
+		for _, gaugevec := range e.queueMetricsGauge {
+			gaugevec.Collect(ch)
+		}
+		for _, countervec := range e.queueMetricsCounter {
+			countervec.Collect(ch)
+		}
 	}
 
-	for _, exchangeMetric := range e.exchangeMetrics {
-		exchangeMetric.Collect(ch)
+	if e.exchangesFetched {
+		for _, exchangeMetric := range e.exchangeMetrics {
+			exchangeMetric.Collect(ch)
+		}
 	}
-
 	BuildInfo.Collect(ch)
 }

exporter_test.go

@@ -151,6 +151,7 @@ func TestWholeApp(t *testing.T) {
 
 	exporter := newExporter()
 	prometheus.MustRegister(exporter)
+	defer prometheus.Unregister(exporter)
 
 	req, _ := http.NewRequest("GET", "", nil)
 	w := httptest.NewRecorder()
@@ -169,4 +170,29 @@ func TestWholeApp(t *testing.T) {
 	expectSubstring(t, body, `rabbitmq_up 1`)
 	expectSubstring(t, body, `rabbitmq_exchange_messages_published_in_total{exchange="myExchange",vhost="/"} 5`)
 	expectSubstring(t, body, `rabbitmq_queue_messages_delivered_total{queue="myQueue1",vhost="/"} 0`)
+
+}
+
+func TestRabbitError(t *testing.T) {
+	server := createTestserver(500, http.StatusText(500))
+	defer server.Close()
+	os.Setenv("RABBIT_URL", server.URL)
+	initConfig()
+
+	exporter := newExporter()
+	prometheus.MustRegister(exporter)
+	defer prometheus.Unregister(exporter)
+
+	req, _ := http.NewRequest("GET", "", nil)
+	w := httptest.NewRecorder()
+	prometheus.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Errorf("Home page didn't return %v", http.StatusOK)
+	}
+	body := w.Body.String()
+	// fmt.Println(body)
+	expectSubstring(t, body, `rabbitmq_up 0`)
+	if strings.Contains(body, "rabbitmq_channelsTotal") {
+		t.Errorf("Metric 'rabbitmq_channelsTotal' unexpected as the server  did not respond")
+	}
 }

main_test.go

@@ -0,0 +1,7 @@
+package main
+
+import log "github.com/Sirupsen/logrus"
+
+func init() {
+	log.SetLevel(log.FatalLevel)
+}