Add HTTP metrics when no mesh provider is specified

Implement request-success-rate and request-duration checks using http_request_duration_seconds histogram

pkg/metrics/factory.go

@@ -24,6 +24,10 @@ func NewFactory(metricsServer string, meshProvider string, timeout time.Duration
 
 func (factory Factory) Observer() Interface {
 	switch {
+	case factory.MeshProvider == "none":
+		return &HttpObserver{
+			client: factory.Client,
+		}
 	case factory.MeshProvider == "appmesh":
 		return &EnvoyObserver{
 			client: factory.Client,

pkg/metrics/http.go

@@ -0,0 +1,71 @@
+package metrics
+
+import "time"
+
+var httpQueries = map[string]string{
+	"request-success-rate": `
+	sum(
+		rate(
+			http_request_duration_seconds_count{
+				kubernetes_namespace="{{ .Namespace }}",
+				kubernetes_pod_name=~"{{ .Name }}-[0-9a-zA-Z]+(-[0-9a-zA-Z]+)",
+				status!~"5.*"
+			}[{{ .Interval }}]
+		)
+	) 
+	/ 
+	sum(
+		rate(
+			http_request_duration_seconds_count{
+				kubernetes_namespace="{{ .Namespace }}",
+				kubernetes_pod_name=~"{{ .Name }}-[0-9a-zA-Z]+(-[0-9a-zA-Z]+)"
+			}[{{ .Interval }}]
+		)
+	) 
+	* 100`,
+	"request-duration": `
+	histogram_quantile(
+		0.99,
+		sum(
+			rate(
+				http_request_duration_seconds_bucket{
+					kubernetes_namespace="{{ .Namespace }}",
+					kubernetes_pod_name=~"{{ .Name }}-[0-9a-zA-Z]+(-[0-9a-zA-Z]+)"
+				}[{{ .Interval }}]
+			)
+		) by (le)
+	)`,
+}
+
+type HttpObserver struct {
+	client *PrometheusClient
+}
+
+func (ob *HttpObserver) GetRequestSuccessRate(name string, namespace string, interval string) (float64, error) {
+	query, err := ob.client.RenderQuery(name, namespace, interval, httpQueries["request-success-rate"])
+	if err != nil {
+		return 0, err
+	}
+
+	value, err := ob.client.RunQuery(query)
+	if err != nil {
+		return 0, err
+	}
+
+	return value, nil
+}
+
+func (ob *HttpObserver) GetRequestDuration(name string, namespace string, interval string) (time.Duration, error) {
+	query, err := ob.client.RenderQuery(name, namespace, interval, httpQueries["request-duration"])
+	if err != nil {
+		return 0, err
+	}
+
+	value, err := ob.client.RunQuery(query)
+	if err != nil {
+		return 0, err
+	}
+
+	ms := time.Duration(int64(value*1000)) * time.Millisecond
+	return ms, nil
+}

pkg/metrics/http_test.go

@@ -0,0 +1,74 @@
+package metrics
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestHttpObserver_GetRequestSuccessRate(t *testing.T) {
+	expected := `sum(rate(http_request_duration_seconds_count{kubernetes_namespace="default",kubernetes_pod_name=~"podinfo-[0-9a-zA-Z]+(-[0-9a-zA-Z]+)",status!~"5.*"}[1m]))/sum(rate(http_request_duration_seconds_count{kubernetes_namespace="default",kubernetes_pod_name=~"podinfo-[0-9a-zA-Z]+(-[0-9a-zA-Z]+)"}[1m]))*100`
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		promql := r.URL.Query()["query"][0]
+		if promql != expected {
+			t.Errorf("\nGot %s \nWanted %s", promql, expected)
+		}
+
+		json := `{"status":"success","data":{"resultType":"vector","result":[{"metric":{},"value":[1,"100"]}]}}`
+		w.Write([]byte(json))
+	}))
+	defer ts.Close()
+
+	client, err := NewPrometheusClient(ts.URL, time.Second)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	observer := &HttpObserver{
+		client: client,
+	}
+
+	val, err := observer.GetRequestSuccessRate("podinfo", "default", "1m")
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	if val != 100 {
+		t.Errorf("Got %v wanted %v", val, 100)
+	}
+}
+
+func TestHttpObserver_GetRequestDuration(t *testing.T) {
+	expected := `histogram_quantile(0.99,sum(rate(http_request_duration_seconds_bucket{kubernetes_namespace="default",kubernetes_pod_name=~"podinfo-[0-9a-zA-Z]+(-[0-9a-zA-Z]+)"}[1m]))by(le))`
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		promql := r.URL.Query()["query"][0]
+		if promql != expected {
+			t.Errorf("\nGot %s \nWanted %s", promql, expected)
+		}
+
+		json := `{"status":"success","data":{"resultType":"vector","result":[{"metric":{},"value":[1,"0.100"]}]}}`
+		w.Write([]byte(json))
+	}))
+	defer ts.Close()
+
+	client, err := NewPrometheusClient(ts.URL, time.Second)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	observer := &HttpObserver{
+		client: client,
+	}
+
+	val, err := observer.GetRequestDuration("podinfo", "default", "1m")
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	if val != 100*time.Millisecond {
+		t.Errorf("Got %v wanted %v", val, 100*time.Millisecond)
+	}
+}