metrics: add /metrics endpoint and console_helm_install_count metric

Works with openshift/console-operator#601 to add
a console_helm_install_count counter vector metric. This change will
increment the counter each time a user installs a Helm chart in the
console.

Closes: https://issues.redhat.com/browse/HELM-235
Signed-off-by: Allen Bai <abai@redhat.com>

pkg/helm/actions/install_chart.go

@@ -1,6 +1,7 @@
 package actions
 
 import (
+	"github.com/openshift/console/pkg/helm/metrics"
 	"helm.sh/helm/v3/pkg/action"
 	"helm.sh/helm/v3/pkg/chart"
 	"helm.sh/helm/v3/pkg/chart/loader"
@@ -40,5 +41,8 @@ func InstallChart(ns, name, url string, vals map[string]interface{}, conf *actio
 	if err != nil {
 		return nil, err
 	}
+
+	metrics.HandleConsoleHelmInstallCount(ch.Metadata.Name, ch.Metadata.Version)
+
 	return release, nil
 }

pkg/helm/metrics/metrics.go

@@ -0,0 +1,34 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"k8s.io/klog/v2"
+)
+
+var (
+	consoleHelmInstallCount = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "console_helm_install_count",
+			Help: "Number of Helm installation from console.",
+		},
+		[]string{"console_helm_chart_name", "console_helm_chart_version"},
+	)
+)
+
+func init() {
+	prometheus.MustRegister(consoleHelmInstallCount)
+}
+
+func HandleConsoleHelmInstallCount(chartName, chartVersion string) {
+	defer recoverMetricPanic()
+
+	klog.V(4).Infof("metric console_helm_install_count: %s %s", chartName, chartVersion)
+	consoleHelmInstallCount.WithLabelValues(chartName, chartVersion).Add(1)
+}
+
+// Reference: https://github.com/openshift/console-operator/blob/master/pkg/console/metrics/metrics.go#L80
+func recoverMetricPanic() {
+	if r := recover(); r != nil {
+		klog.Errorf("Recovering from metric function - %v", r)
+	}
+}

pkg/helm/metrics/metrics_test.go

@@ -0,0 +1,136 @@
+package metrics
+
+import (
+	"bufio"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+const (
+	consoleHelmInstallCountMetric = "console_helm_install_count"
+)
+
+func TestHandleConsoleHelmInstallCountNoRelease(t *testing.T) {
+	consoleHelmInstallCount.Reset()
+	ts := httptest.NewServer(promhttp.Handler())
+	defer ts.Close()
+
+	count := countMetric(t, ts, consoleHelmInstallCountMetric)
+	if count > 0 {
+		t.Errorf("%s should not be available", consoleHelmInstallCountMetric)
+	}
+}
+
+func TestHandleConsoleHelmInstallCountSingleRelease(t *testing.T) {
+	consoleHelmInstallCount.Reset()
+	ts := httptest.NewServer(promhttp.Handler())
+	defer ts.Close()
+
+	chartName, chartVersion := "test-chart", "0.0.1"
+	chartNameLabel, chartVersionLabel := fmt.Sprintf("console_helm_chart_name=\"%v\"", chartName), fmt.Sprintf("console_helm_chart_version=\"%v\"", chartVersion)
+	HandleConsoleHelmInstallCount(chartName, chartVersion)
+
+	count := countMetric(t, ts, consoleHelmInstallCountMetric, chartNameLabel, chartVersionLabel)
+	if count != 1 {
+		t.Errorf("%s with labels %s, %s should be 1: %v", consoleHelmInstallCountMetric, chartNameLabel, chartVersionLabel, count)
+	}
+}
+
+func TestHandleConsoleHelmInstallCountMultipleReleases(t *testing.T) {
+	consoleHelmInstallCount.Reset()
+	ts := httptest.NewServer(promhttp.Handler())
+	defer ts.Close()
+
+	chartName, chartVersion := "test-chart", "0.0.1"
+	chartNameLabel, chartVersionLabel := fmt.Sprintf("console_helm_chart_name=\"%v\"", chartName), fmt.Sprintf("console_helm_chart_version=\"%v\"", chartVersion)
+	HandleConsoleHelmInstallCount(chartName, chartVersion)
+	HandleConsoleHelmInstallCount(chartName, chartVersion)
+
+	count := countMetric(t, ts, consoleHelmInstallCountMetric, chartNameLabel, chartVersionLabel)
+	if count != 2 {
+		t.Errorf("%s with labels %s, %s should be 2: %v", consoleHelmInstallCountMetric, chartNameLabel, chartVersionLabel, count)
+	}
+
+	chartName, chartVersion = "test-chart-2", "0.0.2"
+	chartNameLabel, chartVersionLabel = fmt.Sprintf("console_helm_chart_name=\"%v\"", chartName), fmt.Sprintf("console_helm_chart_version=\"%v\"", chartVersion)
+	HandleConsoleHelmInstallCount(chartName, chartVersion)
+
+	count = countMetric(t, ts, consoleHelmInstallCountMetric, chartNameLabel, chartVersionLabel)
+	if count != 1 {
+		t.Errorf("%s with labels %s, %s should be 1: %v", consoleHelmInstallCountMetric, chartNameLabel, chartVersionLabel, count)
+	}
+
+	count = countMetric(t, ts, consoleHelmInstallCountMetric)
+	if count != 3 {
+		t.Errorf("%s without labels should be 3: %v", consoleHelmInstallCountMetric, count)
+	}
+
+}
+
+func getMetrics(t *testing.T, ts *httptest.Server) *http.Response {
+	res, err := http.Get(ts.URL + "/metrics")
+	if err != nil {
+		t.Errorf("http error: %s", err)
+	}
+
+	if !httpOK(res) {
+		t.Errorf("http error: %d %s", res.StatusCode, http.StatusText(res.StatusCode))
+	}
+	return res
+}
+
+func countMetric(t *testing.T, ts *httptest.Server, metric string, labels ...string) int {
+	res := getMetrics(t, ts)
+	defer res.Body.Close()
+
+	bytes, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		t.Fatalf("read error: %s", err)
+	}
+
+	return countMetricWithLabels(t, string(bytes), metric, labels...)
+}
+
+func countMetricWithLabels(t *testing.T, response, metric string, labels ...string) (count int) {
+	scanner := bufio.NewScanner(strings.NewReader(response))
+	for scanner.Scan() {
+		text := scanner.Text()
+		// skip comments
+		if strings.HasPrefix(text, "#") {
+			continue
+		}
+		if strings.Contains(text, metric) {
+			t.Logf("found %s\n", scanner.Text())
+			curr_count, _ := strconv.Atoi(text[len(text)-1:])
+			// no specific labels, count all
+			if len(labels) == 0 {
+				count += curr_count
+			}
+			// return metric value with specified labels
+			for i, label := range labels {
+				if !strings.Contains(text, label) {
+					break
+				}
+				if i == len(labels)-1 {
+					// return directly since metrics are aggregated
+					return curr_count
+				}
+			}
+		}
+	}
+	return count
+}
+
+func httpOK(resp *http.Response) bool {
+	if resp.StatusCode >= 200 && resp.StatusCode <= 299 {
+		return true
+	}
+	return false
+}

pkg/server/middleware.go

@@ -23,6 +23,13 @@ func authMiddleware(a *auth.Authenticator, hdlr http.HandlerFunc) http.Handler {
 
 func authMiddlewareWithUser(a *auth.Authenticator, handlerFunc func(user *auth.User, w http.ResponseWriter, r *http.Request)) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// Requests from prometheus-k8s have the access token in headers instead of cookies.
+		// This allows metric requests with proper tokens in either headers or cookies.
+		if r.URL.Path == "/metrics" {
+			openshiftSessionCookieName := "openshift-session-token"
+			openshiftSessionCookieValue := r.Header.Get("Authorization")
+			r.AddCookie(&http.Cookie{Name: openshiftSessionCookieName, Value: openshiftSessionCookieValue})
+		}
 		user, err := a.Authenticate(r)
 		if err != nil {
 			klog.V(4).Infof("authentication failed: %v", err)

pkg/server/server.go

@@ -17,6 +17,7 @@ import (
 	"time"
 
 	"github.com/coreos/pkg/health"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 
 	"github.com/openshift/console/pkg/auth"
 	"github.com/openshift/console/pkg/graphql/resolver"
@@ -470,6 +471,10 @@ func (s *Server) HTTPHandler() http.Handler {
 	})
 
 	// Helm Endpoints
+	handle("/metrics", authHandler(func(w http.ResponseWriter, r *http.Request) {
+		promhttp.Handler().ServeHTTP(w, r)
+	}))
+
 	handle("/api/helm/template", authHandlerWithUser(helmHandlers.HandleHelmRenderManifests))
 	handle("/api/helm/releases", authHandlerWithUser(helmHandlers.HandleHelmList))
 	handle("/api/helm/chart", authHandlerWithUser(helmHandlers.HandleChartGet))