Add up metric

exporter/newrelic_exporter.go → exporter/exporter.go

@@ -1,19 +1,27 @@
 package exporter
 
 import (
+	"sync"
+
+	"github.com/ContaAzul/newrelic_exporter/newrelic"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
 )
 
 const namespace = "newrelic"
 
 // Exporter collects metrics from a NewRelic application
 type Exporter struct {
+	mutex  sync.RWMutex
+	client *newrelic.Client
+
 	up *prometheus.Desc
 }
 
 // NewExporter returns an initialized exporter.
 func NewExporter(apiKey string) *Exporter {
 	return &Exporter{
+		client: newrelic.NewClient(apiKey),
 		up: prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, "", "up"),
 			"NewRelic API is up and accepting requests",
@@ -32,5 +40,17 @@ func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
 // Collect fetches the metrics data from the NewRelic application and
 // delivers them as Prometheus metrics. It implements prometheus.Collector.
 func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
+	// To protect metrics from concurrent collects.
+	e.mutex.Lock()
+	defer e.mutex.Unlock()
+
+	//TODO: Use correct application ID to scrape data
+	_, err := e.client.ListInstances(0)
+	if err != nil {
+		log.Errorf("Failed to get application instances: %v", err)
+		ch <- prometheus.MustNewConstMetric(e.up, prometheus.GaugeValue, 0)
+		return
+	}
+
 	ch <- prometheus.MustNewConstMetric(e.up, prometheus.GaugeValue, 1)
 }

main.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/ContaAzul/newrelic_exporter/exporter"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/common/log"
 	"gopkg.in/alecthomas/kingpin.v2"
 )
@@ -29,7 +30,7 @@ func main() {
 
 	prometheus.MustRegister(exporter.NewExporter(*apiKey))
 
-	http.Handle("/metrics", prometheus.Handler())
+	http.Handle("/metrics", promhttp.Handler())
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		fmt.Fprintf(w,
 			`
@@ -45,6 +46,6 @@ func main() {
 
 	log.Infof("Server listening on %s", *addr)
 	if err := http.ListenAndServe(*addr, nil); err != nil {
-		log.Fatalf("Error starting server: %s", err)
+		log.Fatalf("Error starting server: %v", err)
 	}
 }