feat(RHTAPWATCH-570): Update exporters code with actual metrics

Update the dsexporter code and related unit tests with
actual metrics.

Signed-off-by: Homaja Marisetty <[email protected]>

exporters/dsexporter/dsexporter.go

@@ -9,31 +9,57 @@ import (
 )
 
 type CustomCollector struct {
-	requestCounter prometheus.Counter
+	konfluxProbeSuccess *prometheus.GaugeVec
 }
 
 // Creating a new instance of CustomCollector.
 func NewCustomCollector() *CustomCollector {
 	return &CustomCollector{
-		requestCounter: prometheus.NewCounter(prometheus.CounterOpts{
-			Name: "request_count",
-			Help: "Number of requests handled by the handler",
-		}),
+		konfluxProbeSuccess: prometheus.NewGaugeVec(prometheus.GaugeOpts{
+			Name: "konflux_probe_success",
+			Help: "Availability of konflux service/component",
+		},
+		[]string{"service", "check"}),
 	}
 }
 
 // Describe method sends descriptions of the metrics to Prometheus.
 // When Prometheus scrapes the /metrics endpoint of the exporter,
 // it first calls the Describe method to get a description of all the metrics.
 func (e *CustomCollector) Describe(ch chan<- *prometheus.Desc) {
-	e.requestCounter.Describe(ch)
+	e.konfluxProbeSuccess.Describe(ch)
 }
 
 // Collect method sends the current values of the metrics to Prometheus.
 // After Prometheus understands what metrics are available (using the `Describe` method),
 // it then calls the `Collect` method to actually get the values of those metrics.
 func (e *CustomCollector) Collect(ch chan<- prometheus.Metric) {
-	e.requestCounter.Collect(ch)
+	e.konfluxProbeSuccess.Collect(ch)
+}
+
+func availabilityHandler(response http.ResponseWriter, req *http.Request, exporter *CustomCollector) {
+	service := req.URL.Query().Get("service")
+	check := req.URL.Query().Get("check")
+	availability := checkIfServiceUp(service)
+
+	exporter.konfluxProbeSuccess.WithLabelValues("service", "check").Set(availability)
+	fmt.Fprintf(response, "Service: %s, Check Name: %s, Availability: %f", service, check, availability)
+}
+
+func checkIfServiceUp(service string) float64 {
+	serviceUrl := "https://" + service
+
+	resp, err := http.Get(serviceUrl)
+	if err != nil {
+		return 0
+	}
+
+	defer resp.Body.Close()
+	if resp.StatusCode == http.StatusOK {
+		return 1
+	} else {
+		return 0
+	}
 }
 
 // Using a separate pedantic registry ensures that only your custom metric is exposed on the "/metrics" endpoint,
@@ -43,13 +69,18 @@ func main() {
 	exporter := NewCustomCollector()
 	reg.MustRegister(exporter)
 
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		availabilityHandler(w, r, exporter)
+ 	})
+
 	http.Handle("/metrics", promhttp.HandlerFor(
 		reg,
 		promhttp.HandlerOpts{
 			EnableOpenMetrics: true,
 			Registry:          reg,
 		},
 	))
+
 	fmt.Println("Server is listening on http://localhost:8090/metrics")
 	http.ListenAndServe(":8090", nil)
 }

exporters/dsexporter/dsexporter_test.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"testing"
+	"net/http"
+	"net/http/httptest"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/stretchr/testify/assert"
@@ -16,31 +18,50 @@ func TestCustomCollector(t *testing.T) {
 	metricFamilies, err := metrics.Gather()
 	assert.NoError(t, err)
 
-	var RequestCountValue float64
+	var konfluxProbeSuccessValue float64
 	for _, mf := range metricFamilies {
-		if mf.GetName() == "request_count" {
-			RequestCountValue = mf.GetMetric()[0].GetCounter().GetValue()
+		if mf.GetName() == "konflux_probe_success" {
+			konfluxProbeSuccessValue = mf.GetMetric()[0].GetCounter().GetValue()
 			break
 		}
 	}
 
 	// Check whether the exported metric value is initially 0.
-	assert.Equal(t, float64(0), RequestCountValue)
+	assert.Equal(t, float64(0), konfluxProbeSuccessValue)
 
-	// Increment the requestCounter by calling the Inc method.
-	exporter.requestCounter.Inc()
+	// Increment the konfluxProbeSuccess by calling the Inc method.
+	exporter.konfluxProbeSuccess.With(prometheus.Labels{"service":"test_service", "check":"github"}).Inc()
 
 	// Collecting metrics again
 	metricFamilies, err = metrics.Gather()
 	assert.NoError(t, err)
 
 	for _, mf := range metricFamilies {
-		if mf.GetName() == "request_count" {
-			RequestCountValue = mf.GetMetric()[0].GetCounter().GetValue()
+		if mf.GetName() == "konflux_probe_success" {
+			konfluxProbeSuccessValue = mf.GetMetric()[0].GetCounter().GetValue()
 			break
 		}
 	}
 
 	// Check whether the exported metric value is now 1 after incrementing.
-	assert.Equal(t, float64(1), RequestCountValue)
+	assert.Equal(t, float64(1), konfluxProbeSuccessValue)
+}
+
+func TestcheckIfServiceUp(t *testing.T) {
+	exporter := NewCustomCollector()
+	mockHandler := http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		availabilityHandler(w, r, exporter)
+	})
+
+	mockServer :=httptest.NewServer(mockHandler)
+	defer mockServer.Close()
+
+	serviceUrl := mockServer.URL
+
+	available := checkIfServiceUp(serviceUrl)
+
+	if available == 0 {
+		t.Error("Service not accessible")
+	}
 }